Forecast Discussions mentioning "ACARS", "MDCRS", "AIRCRAFT", "TAMDAR", or "AMDAR" received at FSL on 02/16/07


AREA FORECAST DISCUSSION...UPDATE TO AVIATION AND MEDIA SECTIONS.
NWS UPTON NY
915 AM EST WED FEB 14 2007 .MEDIA...ICE STORM WARNING BEING EXPANDED IN COASTAL CT. SEE NYCWSWOKX / WWUS41 KOKX COMING OUT SHORTLY. SEE NYCRR8OKX / SRUS81 KOKX FOR SNOW AMOUNTS FOR NOW. PUBLIC INFO STATEMENTS WILL BE ISSUED AS WE CATCH UP. .EQUIPMENT... ATTENTION ALL USERS...POINT AND CLICK FORECASTS ON THE NWS UPTON WEBPAGE ARE NOT UPDATING AT THIS TIME. OUR REGIONAL HQ HAS BEEN NOTIFIED AND WILL BE WORKING ON THE PROBLEM. THIS PROBLEM APPEARS TO BE AFFECTING NEIGHBORING WFOS INCLUDING BOX/ALY/BGM/PHI AT THIS TIME. USERS CAN FIND UPDATED WEATHER INFORMATION BY CLICKING ON THE /LOCAL WEATHER/ LINK ON THE LEFT HAND SIDE OF THE MAIN WFO UPTON HOMEPAGE...THEN SELECTING THE TEXT PRODUCT OF INTEREST. THE LATEST ZONE FORECAST PRODUCT CAN BE FOUND BY SELECTING THE INDICATED LINK BELOW THE POINT AND CLICK MAP. && .NEAR TERM /TODAY AND TONIGHT/... MORE WARM AIR HAS WORKED IN ALOFT THAN PREVIOUSLY EXPECTED WITH OKX 6Z SOUNDING SHOWING A 100MB LAYER UP TO 3C ABOVE FREEZING FROM 840 TO 740 MB...AND AMDAR SOUNDINGS AT PHI SHOWING A DEEP LAYER ABOVE 3000 FEET OF UP TO 5C. THAT AIR IS WORKING ITS WAY INTO OUR REGION. AS A RESULT HAVE HAD TO SWITCH THE FOCUS TO FREEZING RAIN AS THE MAIN PRECIPITATION THREAT...AND HAVE CUT BACK ON SNOW AMOUNTS AS A RESULT. STILL EXPECT PRECIPITATION TO CHANGE OVER TO RAIN ACROSS EASTERN LONG ISLAND AND COASTAL EASTERN CONNECTICUT...AND LIKELY TO MIX WITH AND POSSIBLY CHANGE TO RAIN ACROSS WESTERN LONG ISLAND...WITH THE BEST CHANCE NEAR THE SOUTH SHORE (INCLUDING SOUTHERN PORTIONS OF NEW YORK CITY). SUMMARY OF CHANGES AS FOLLOWS: HAVE ISSUED AN ICE STORM WARNING FOR MOST OF NORTHEAST NEW JERSEY...NORTHWEST NYC (MANHATTAN AND THE BRONX) AND SOUTHERN WESTCHESTER COUNTY. EXPECT PRECIPITATION THERE TO SWITCH TO PRIMARILY FREEZING RAIN (WITH SOME SLEET AT TIMES) DURING THE MORNING RUSH...AND CONTINUE INTO THE AFTERNOON BEFORE SWITCHING BACK OVER TO SNOW. HAVE THE POTENTIAL FOR 1/2-3/4 OF AN INCH OF ICE ACCRETION THERE WITH 2-5 INCHES OF SNOW/SLEET. RAIN COULD MIX IN BRIEFLY IN EARLY AFTERNOON IN NYC...ESPECIALLY ACROSS SOUTHERN MANHATTAN. CONTINUED WINTER STORM WARNING FOR REMAINDER OF LOWER HUDSON VALLEY (INCLUDING ALL OF ORANGE AND WESTERN PASSAIC) AND INTERIOR WESTERN CT...BUT REDUCED SNOW/SLEET ACCUMULATIONS TO 3 TO 6 INCHES (7-15 ORANGE COUNTY) WITH A 1/4 TO 1/2 INCH OF ICE. NW ORANGE COUNTY SHOULD BE MAINLY SNOW AND SLEET...WITH MORE ICE IN SE PORTIONS OF THAT AREA. CONTINUED WINTER WEATHER ADVISORIES ELSEWHERE...FOR EASTERN CT AND EASTERN SUFFOLK COUNTY ZONES EXPECT 1-2 INCHES SNOW/SLEET AND UP TO .1 ICE AS EXPECT PRECIPITATION TO CHANGE OVER TO ALL RAIN THERE BY AROUND MIDDAY. ACROSS THE REMAINDER OF LONG ISLAND (INCLUDING QUEENS AND BROOKLYN)...STATEN ISLAND...AND COASTAL WESTERN CT EXPECT THE COLD AIR AT THE SURFACE TO HANG IN LONGER (PER 3HR TEMP TRENDS IN ALL AVAILABLE GUIDANCE...AND RECENT TEMPERATURE TRENDS ONLY SHOWING LITTLE TEMPERATURE CHANGE OVERNIGHT...WITH TEMPERATURES STILL IN THE L-M20S ON LONG ISLAND...AND TEENS IN CT WITH DEWPOINTS FROM THE TEENS TO AROUND 20...SHOWING COLD AIR REMAINING IN PLACE. AS A RESULT EXPECT FROM 1/10-1/4 INCH OF ICE IN THAT GROUP BEFORE RAIN MIXES IN BY EARLY AFTERNOON. BRIEF COMMENT ON THE MODELS...PREFER SLIGHTLY MORE OFFSHORE AND QUICKER GFS OVER THE NAM (OUTLIER IN ITS SLOWNESS). GFS HAD GOOD SUPPORT FORM THE CANADIAN AND ECMWF. NO MODEL HAS PROPERLY DIAGNOSED THE WARM AIR ALOFT...SO BUFKIT SOUNDINGS WERE PUTTING TOO MUCH EMPHASIS ON SLEET VICE FREEZING RAIN AS THE PREDOMINATE PRECIP TYPE. IT APPEARS THAT THERE WILL BE SUFFICIENT MOISTURE AVAILABLE AS COLD AIR BUILDS IN BEHIND THE LOW LATE THIS AFTERNOON/EARLY THIS EVENING TO CHANGE PRECIPITATION BACK TO SNOW BEFORE IT ENDS BY MID EVENING. COULD SEE A QUICK BURST OF UP TO 2 INCHES DEPENDING ON LOCATION...AS THERE IS SOME EVIDENCE THAT THE DEFORMATION AXIS ON THE BACK SIDE OF THE SYSTEM COULD CROSS THE AREA...GIVING SUFFICIENT DYNAMICS TO SUPPORT THIS. HAVE EXPANDED EXISTING WIND ADVISORY TO INCLUDE THE REMAINDER OF COASTAL CT AND NYC. COULD SEE SOME GUSTS OF 35-40 KT AT TIMES THIS MORNING OUT AHEAD OF THE LOW AROUND NYC...WHILE AREAS FURTHER EAST COULD EVEN SEE SUSTAINED WINDS NEAR THE WIND ADV CRITERIA. EVEN GREATER RISK OF STRONG WINDS WILL OCCUR BEHIND THE LOW PRESSURE AREA LATE THIS AFTERNOON AND TONIGHT. WIND GUSTS OF 40-50 MPH ARE LIKELY ACROSS THE ADVISORY AREA DURING THIS TIME... WITH A FEW HIGHER GUSTS POSSIBLE. BUFKIT AND OTHER MODEL DATA DOES NOT SUPPORT WIDESPREAD 50 KT GUSTS...SO FEEL THAT WIND ADVISORY WILL SUFFICE RATHER THAN HIGH WIND WARNING. LATER SHIFTS WILL NEED TO MONITOR THOUGH. FOR TEMPERATURES OPTED FOR THE COLDEST AVAILABLE GUIDANCE...EXCEPT OVER FAR EASTERN PORTIONS WHERE BLENDED THE TWO WARMER GUIDANCE VALUES. THINGS THEN GET COLD QUICKLY TONIGHT...WITH ANY LIQUID ON NON-TREATED ROADWAYS FREEZING...COULD MAKE THE END OF THE EVENING COMMUTE TREACHEROUS. EXPECT LOWS GENERALLY IN THE TEENS WITH SINGLE DIGITS N/W OF NYC METRO. GUSTY WINDS WILL PRODUCE WIND CHILLS AROUND ZERO IN COASTAL SECTIONS AND IN THE NEGATIVE SINGLE DIGITS ELSEWHERE. && .SHORT TERM /THURSDAY THROUGH FRIDAY/... COLD AND DRY AS HIGH PRESSURE BUILDS IN FROM THE WEST AND A SERIES OF SHORTWAVES WORK ACROSS THE REGION...BUT WITH LIMITED MOISTURE...WILL RESULT IN AT MOST PARTLY CLOUDY SKY CONDITIONS. FOLLOWED A BLEND OF COLDER GUIDANCE WITH TEMPERATURES STAYING WELL BELOW NORMAL AND FREEZING. && .LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/... LONG TERM APPEARS ON TRACK SO NO CHANGES WERE MADE. LONG TERM SECTION FROM PREVIOUS AFD FOLLOWS: QUIET WEATHER IN STORE THROUGH THE END OF THE WEEK AND THE FIRST HALF OF THE WEEKEND. WESTERLY TO SOUTHWESTERLY WIND FLOW WILL HELP WARM UP TEMPERATURES SLIGHTLY THROUGH THE REMAINDER OF THE PERIOD. TEMPS MAX ARE EXPECTED TO BE IN THE LOWER TO MID 30S WITH LOW TEMPERATURES IN THE MID TEENS TO AROUND 20. THE NEXT SYSTEM TO AFFECT THE LOCAL AREA IS EXPECTED TO APPROACH ON SUNDAY...AT THIS TIME IT LOOKS LIKE THIS SYSTEM WILL BRING A CHANCE OF SNOW ACROSS THE COLDER NORTHERN ZONES AND A MIX OF SNOW AND RAIN ACROSS THE SOUTHERN ZONES. DRY WEATHER RETURNS MONDAY AND TUESDAY AS A RIDGE OF HIGH PRESSURE BUILDS INTO THE AREA. && .AVIATION...(UPDATED!) NOR`EASTER MOVING NORTHEAST LOCATED OF THE DELAWARE COAST WILL PASS OVER EASTERN LONG ISLAND THIS AFTERNOON. COASTAL FRONT BEING ESTABLISHED ACROSS LONG ISLAND. NYC METRO AND KISP TAF WERE AMENDED. MORE CONFIDENCE IN THE WIND FORECAST BACKING AROUND TO NORTHWEST EARLIER IN COLLABORATION WITH ZNY. FAA CC BRIEFED ON CHANGES. P-TYPE MAINLY FZRA IN NYC METRO THEN SN MIXES BACK WITH MORE PL THIS AFTERNOON. KJFK COULD GO TO PLAIN RAIN FOR A PERIOD AROUND 15-16Z...BUT CONFIDENCE IS LOW. THINKING IS KFRG GET TO RA...BUT NOT KJFK - CLOSE CALL. WIND SHEAR ADDED INITIALLY...BUT THIS LIFTS SOON. COMPRESSION PROBLEMS POSSIBLE. LOW PRES MOVES INTO THE GULF OF MAINE LATE THIS THIS EVENING...RESULTING IN STRONG NW AT 20-30G35-40KT THIS EVENING AND TONIGHT. WIND IMPACTS AT KEWR. && .MARINE... COASTAL STORM WILL MOVE THROUGH THE REGION TODAY. GALE WARNINGS ARE NOW POSTED FOR ALL WATERS. WINDS ALREADY GUSTING TO 35 KT AT 08Z AT THE OCEAN BUOYS...AND EXPECT THE HARBOR AND SOUND TO INCREASE TO GALE FORCE EARLY THIS MORNING. FAVORED THE SLIGHTLY FASTER GFS TRACK WITH THE SFC LOW MOVING THROUGH THE COASTAL WATERS TODAY...WHICH TAKES THE LOW JUST EAST OF MONTAUK POINT DURING THE AFTERNOON. WINDS WILL INCREASE TO 30-35 KT SUSTAINED WITH GUSTS OF 40-45 KT LIKELY. COULD SEE AN OCNL/ISOLATED GUST TO 50 KT...BUT NOT EXPECTING THESE TO BE COMMON AND WILL NOT POST STORM WARNING AT THIS POINT. WINDS WILL SHIFT TO NW AS THE LOW PASSES BY...WITH GALE CONDITIONS CONTINUING. GUSTS OF 35-45 KT WILL PREVAIL ACROSS ALL WATERS THROUGH TONIGHT AND THURS MORNING. AGAIN COULD SEE A FEW GUSTS TO 50 KT...BUT EXPECTING THESE TO BE ISOLATED. THE GRADIENT REMAINS TIGHT ON THURS AS THE LOW MOVES SLOWLY THROUGH THE CANADIAN MARITIMES AND HIGH PRESSURE NOSES INTO THE MID ATLANTIC. WINDS SHOULD DROP BELOW GALE FORCE ACROSS THE WRN SOUND AND HARBOR BY THU AFTERNOON...BUT GALES WILL CONTINUE THROUGH THE AFTERNOON ELSEWHERE. EXTENDED THE GALE WARNING OUT THROUGH THU NIGHT FOR THE EASTERN OCEAN ZONES...WHERE CONFIDENCE IS HIGH THAT GUSTS OF 35-40 KT WILL CONTINUE. SEAS ON THE OCEAN TODAY AND TONIGHT WILL GENERALLY RANGE IN THE 10 TO 15 FT RANGE...WHILE BUILDING TO 6 TO 8 FT ON LI SOUND. WW3 GUIDANCE REFLECTED THIS SCENARIO AND WAS FOLLOWED. IN ADDITION TO THE STRONG WINDS...A LONG ENE WILL PUSH WATER INTO LONG ISLAND SOUND...NEW YORK HARBOR AND THE BACK BAYS ALONG THE SOUTH SHORE OF LONG ISLAND. THE HEIGHT AND TIMING OF THE ASTRONOMICAL TIDES ARE HELPFUL FOR PREVENTING SIGNIFICANT COASTAL FLOODING DURING THIS PARTICULAR EVENT. ASTRO TIDES ARE QUITE LOW RIGHT NOW WITH THE RECENT FIRST QUARTER MOON. THUS WE WILL REQUIRE 2-3 FT DEPARTURES TO REACH MINOR FLOODING BENCHMARKS...AND 3 TO 4.5 FT TO REACH MODERATE. ALSO THE GREATEST DEPARTURES WILL OCCUR DURING THE LATE MORNING THROUGH MID AFTERNOON TODAY...WHICH IS AROUND THE TIME OF ASTRO LOW TIDE. DEPARTURES WILL JUST BE STARTING TO BUILD UP DURING THIS MORNINGS HIGH TIDE...AND WINDS ARE EXPECTED TO HAVE SHIFTED OFFSHORE BY THE EVENING HIGH TIDE. TIDAL DEPARTURES OF 2 TO 2 1/2 FEET ABOVE NORMAL ARE EXPECTED ON LONG ISLAND SOUND AND 1 TO 1 1/2 FEET ABOVE NORMAL ALONG THE SOUTH SHORE OF LONG ISLAND AND IN NY HARBOR WED MORNING. THEREFORE AT THIS POINT LOOKING FOR ONLY ISOLATED/LOCAL MINOR COASTAL FLOODING DURING THIS EVENT...WITH WESTERN LONG ISLAND SOUND HAVING THE HIGHEST POTENTIAL. WITH AIR TEMPS DROPPING BELOW FREEZING TONIGHT AND THURS...ALONG WITH GALE FORCE WINDS AND ROUGH SEAS...FREEZING SPRAY WILL BE A CONCERN ON THE OCEAN AND IN LI SOUND. WILL ALSO HAVE TO WATCH OUT FOR LOW WATER PROBLEMS ON THU. WEST WINDS REMAIN STRONG AS THE LOW CONTINUES TO STRENGTHEN WHILE MOVING INTO NORTHERN NEW ENGLAND AND SOUTHEAST CANADA. MRPSSE GUIDANCE SHOWS TIDES DROPPING TO 2-3 FT BELOW NORMAL THU. WITH ALL OF THE OTHER ISSUES TO DEAL WITH IN THE NEAR TERM...WILL NOT ISSUE LOW WATER ADVISORY YET...BUT LATER SHIFTS WILL DEFINITELY NEED TO CONSIDER IT. && .HYDROLOGY... STILL LOOKING AT 1.5 TO 2.5 INCHES OF QPF POSSIBLE WITH THIS SYSTEM...MOST OF THE PRECIPITATION WILL FALL IN THE FROZEN/FREEZING FORM...SO THERE WILL BE LITTLE IMMEDIATE IMPACT ON AREA STREAMS AND RIVERS. OVER EASTERN CT/LONG ISLAND...MINOR URBAN/RURAL FLOODING COULD OCCUR...WITH AROUND 1/2 OF THE QPF BEING PLAIN RAIN ON TOP OF A COATING OF SNOW AND ICE...PROMOTING MAINLY A RUNOFF FLOW. OTHERWISE EXPECT NO SIGNIFICANT QPF THROUGH THE PERIOD. SO OTHER THAN SLIGHT RISES CAUSED BY MELTING OF ANY FROZEN WATER EARLY NEXT WEEK...EXPECT RIVERS TO SLOWLY FALL...EXCEPT FOR FLUCTUATIONS DUE TO AREAS OF ICE FORMATION. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...WINTER WEATHER ADVISORY UNTIL 10 PM EST THIS EVENING FOR CTZ007>012. WIND ADVISORY FROM 9 AM THIS MORNING TO 6 AM EST THURSDAY FOR CTZ007>012. WINTER STORM WARNING UNTIL 10 PM EST THIS EVENING FOR CTZ005- 006. NY...WINTER WEATHER ADVISORY UNTIL 10 PM EST THIS EVENING FOR NYZ075>081. WIND ADVISORY FROM 9 AM THIS MORNING TO 6 AM EST THURSDAY FOR NYZ071>081. WINTER STORM WARNING UNTIL 10 PM EST THIS EVENING FOR NYZ067>070. ICE STORM WARNING UNTIL 6 PM EST THIS AFTERNOON FOR NYZ071>073. NJ...WIND ADVISORY FROM 9 AM THIS MORNING TO 6 AM EST THURSDAY FOR NJZ006. WINTER STORM WARNING UNTIL 10 PM EST THIS EVENING FOR NJZ002. ICE STORM WARNING UNTIL 6 PM EST THIS AFTERNOON FOR NJZ003>006- 011. MARINE...GALE WARNING UNTIL 1 PM EST THURSDAY FOR ANZ335-338. GALE WARNING UNTIL 6 PM EST THURSDAY FOR ANZ330. GALE WARNING UNTIL 6 PM EST THURSDAY FOR ANZ355. GALE WARNING UNTIL 4 AM EST FRIDAY FOR ANZ350-353. && $$ AVIATION...TONGUE SHORT TERM...PFM LONG TERM...PFM MARINE...CJ
AREA FORECAST DISCUSSION...UPDATED
NWS MOUNT HOLLY NJ
925 AM EST WED FEB 14 2007 .UPDATE... SURFACE LOW JUST OFF BUOY 44409 AND MOVING SLOWLY NNE HUGGING THE NJ COAST. BY 00Z LOW WILL BE NEAR CAPE COD. COMPOSITE RADAR SHOWS AN END TO THE PRECIPITATION ACROSS THE DELAWARMA AND MOST OF DELAWARE INTO EXTRME SNJ. WIDE RANGE OF TEMPERATURES UPPER 40S ALONG SOUTHEAST COAST TO THE TEENS NW OF PHL. WILL BE UPDATING SOME PUBLIC PRODUCTS AND CANCELLING SEVERAL WATCHES AND WARNINGS. GOOD MIXTURE CONTINUES IN THE LEHIGH VALLEY AND THIS WILL CONTINUE FOR A COUPLE MORE HOURS. WINDS ON THE SRN DEL COAST AROUND TO THE WEST AND NORTHWEST, SO WE`LL BE SAYING GOODBY TO THE NEAR 50 DEGREE TEMPERATURES. .AVIATION UPDATE... WIDE AREA OF IFR ACROSS THE EASTERN US WITH A POCKET OF VFR WX IN NORTHERN VIRGINIA. AS THE SYSTEM MOVES TO THE NORTHEAST, SOME CLEARING MAY MOVE INTO SOUTHERN PA BUT WITH A RETURN TO COLD AIR ADVECTION, SOME LOWER CLOUDS RETURN IF WE GET THE BREAK AND SNOW SHOWERS IN THE AFTERNOON. WILL TAKE A CLOSER LOOK SHORTLY. && .MARINE...UPDATE MARINE SENT BUT ONLY TO END SOME PCPN THIS MORNING. && EBERWINE .AVIATION UPDATE /12Z-12Z/... THE 6:00 AM TEMP AT KPHL WAS 29 DEGREES, WHICH MIGHT BE THE HIGH FOR THE DAY THERE AS THE WIND CONTINUES TO BACK TO A MORE NORTHERLY DIRECTION. CONDITIONS REMAINED RELATIVELY WARM AT KMIV AND KACY, AND THEY SHOULD STAY ABOVE FREEZING THROUGH MID TO LATE AFTERNOON. HOWEVER, IT`S LOOKING MORE AND MORE LIKELY THAT KPHL, KILG, KPNE AND KTTN WILL REMAIN BELOW FREEZING. MEANWHILE, KABE AND KRDG SHOULD NOT GET MUCH ABOVE THE LOWER 20S TODAY. WITH NOT MUCH AIR TRAFFIC INTO OR OUT OF KPHL OVER THE PAST SEVERAL HOURS, WE WERE UNABLE TO FIND ANY RECENT ACARS DATA. HOWEVER, LOOKING AT THE VAD WIND PROFILE FROM KDIX, IT LOOKS AS THOUGH THE COLD AIR REMAINS ABOUT 3000 FEET THICK OVER KPHL AND VCNTY. QUITE A DEEP LAYER OF COLD AIR TO ERODE WHILE FIGHTING A NORTHEAST SURFACE WIND THAT IS REINFORCING THE COLD AIR IN THE LOWEST LEVELS. AS A RESULT OF THE EXPECTED SURFACE TEMPS, AND WITH A GOOD DEAL OF WARM AIR ALOFT, THE MAIN PRECIP TYPES SHOULD BE SNOW AND SLEET WITH A LITTLE FREEZING RAIN AT KRDG AND KABE, AND FREEZING RAIN WITH SOME SLEET AT KTTN, KPNE, KPHL AND KILG. IT SHOULD REMAIN ALL RAIN AT KMIV AND KACY INTO EARLY AFTERNOON. AS THE WIND BACKS TO THE NORTHWEST THIS AFTERNOON, THE PRECIP SHOULD CHANGE BACK TO SNOW AND SLEET AT THE TAIL END OF THE EVENT FOR ALL EIGHT OF OUR TAF SITES. WE`VE KEPT IFR CEILINGS FOR THE BALANCE OF THIS MORNING. CEILINGS MAY IMPROVE SLIGHTLY, PERHAPS TO 1000 OR 1500 FEET FOR THIS AFTERNOON AND EVENING AS THE WIND BACKS TO THE NORTHWEST. VSBY VALUES SHOULD BOUNCE FROM MVFR TO IFR AT LEAST THROUGH MID AFTERNOON AS PRECIP RATES VARY. BASED ON RADAR DATA AND GUIDANCE, WE`RE CONTINUING TO EXPECT THE HEAVIEST PRECIP THROUGH ABOUT 1500 UTC. THE CLOUD COVER IS NOT EXPECTED TO GO OVER TO SCATTERED UNTIL TONIGHT. && .PREV DISCUSSION... /ISSUED 518 AM EST WED FEB 14 2007/ UPDATE... UPDATED PUBLIC PRODUCTS ISSUED TO DROP THE ADVISORY FOR MARYLANDS EASTERN SHORE COUNTIES. THE COASTAL FLOOD ADVISORY HAS ALSO BEEN CANCELED. PREV DISCUSSION... /ISSUED 417 AM EST WED FEB 14 2007/ SHORT TERM /TODAY THROUGH THURSDAY NIGHT/... A 995 MB LOW WAS LOCATED OVER THE VA COAST EARLY THIS MORNING. PRESSURES ARE FALLING RAPIDLY WITH THE LOW AND IT IS EXPECTED TO TRACK NORTHWARD TODAY ALONG THE COAST. SIGNIFICANT AMOUNTS OF MOISTURE AND DYNAMICS ACCOMPANY THE LOW, SO A WEALTH OF WEATHER PROBLEMS EXPECTED OVER OUR REGION TODAY. AN ICE STORM WARNING HAS BEEN ISSUED FOR MUCH OF THE DELAWARE VALLEY AND UP INTO NE NJ. TEMPERATURES IN THESE AREAS NOT CHANGING TOO MUCH AS A SIGNIFICANT PUNCH OF WARM AIR HAS ARRIVED ALOFT. ICE ACCUMULATIONS OF 1/4 TO 1/2 INCH EXPECTED, WITH PERHAPS 1/2 OF INCH OF SLEET AS WELL. THIS WEATHER WILL HAVE SIGNIFICANT IMPACTS ON TRAVEL ACROSS THE AREA TODAY. TRAVEL, ONLY IF NECESSARY AND PLAN ON A MUCH LONGER THAN NORMAL JOURNEY. IN THE SOUTHERN POCONOS AND NORTHERN NJ, THE PRECIPITATION SHOULD REMAIN ALL SNOW WITH ACCUMULATIONS UP TO A FOOT IN THESE AREAS. THE SNOW SHOULD WIND DOWN EARLY TONIGHT, BUT BRISK WINDS MAY CAUSE SOME BLOWING SNOW ISSUES. WIND CHILL READINGS WILL DROP TO 0 TO -10 TONIGHT. FURTHER TO THE SOUTH, THE WINTER WEATHER ADVISORY IS STILL IN EFFECT FOR THE EASTERN SHORE AREAS OF MD, WHERE TEMPERATURES HAVE LINGERED NEAR FREEZING. I EXPECT TO BE ABLE TO DROP THAT SHORTLY AS TEMPERATURES ARE SLOWLY RISING ABOVE FREEZING TO THE SOUTH. THE ADVISORY IN OTHER AREAS WAS DROPPED EARLIER, AS THE EAST WIND OFF THE OCEAN HAS BROUGHT WARMER TEMPERATURES WITH IT. WEATHER CONDITIONS WILL IMPROVE FROM SOUTH TO NORTH THIS AFTERNOON AS COOLER AND DRIER AIR FLOWS IN FROM THE NW BEHIND THE DEPARTING LOW. THE BRISK CONDITIONS WILL LAST THROUGH THE NIGHT AND INTO THURSDAY WITH LITTLE SNOW EXPECTED, EXCEPT SOME SNOW SHOWERS IN THE POCONOS. LONG TERM /FRIDAY THROUGH TUESDAY/... NO CHANGES WERE MADE TO THE EXTENDED FORECAST FOR THE MORNING ISSUANCE. A CLIPPER SYSTEM MAY BRING SOME SNOW SHOWERS TO THE REGION SATURDAY NIGHT AND SUNDAY. MARINE... WE HAVE NOT MADE MUCH CHANGE TO THE MARINE FORECAST EARLY THIS MORNING. AT 3:00 AM, THE LOW WAS CENTERED OVER EXTREME NORTHEASTERN NORTH CAROLINA. IT WILL ZIP TO THE NORTHEAST, PASSING OVER OR JUST TO THE EAST OF OUR OCEAN WATERS DURING THE LATE MORNING AND EARLY AFTERNOON. IT WILL CONTINUE ON TO SOUTHEASTERN NEW ENGLAND BY EVENING. THE STRONG FLOW, ESPECIALLY ON THE BACK SIDE OF THE SYSTEM, WILL CONTINUE TO NECESSITATE A GALE WARNING. WE HAVE EXTENDED THE GALE WARNING UNTIL NOON ON THURSDAY FOR OUR OCEAN WATERS AND FOR DELAWARE BAY. CONDITIONS SHOULD SETTLE DOWN A BIT FOR FRIDAY AND THE WEEKEND, WITH PERHAPS A CLIPPER TYPE SYSTEM ON SATURDAY NIGHT. && .PHI WATCHES/WARNINGS/ADVISORIES... PA...ICE STORM WARNING UNTIL 10 AM EST THIS MORNING FOR PAZ067>071. WINTER STORM WARNING UNTIL 7 PM EST THIS EVENING FOR PAZ054- 055. FLOOD WATCH THROUGH THIS EVENING FOR PAZ070-071. WINTER STORM WARNING UNTIL NOON EST TODAY FOR PAZ060>062. NJ...ICE STORM WARNING UNTIL 10 AM EST THIS MORNING FOR NJZ008>010- 012-013-015>019. WINTER STORM WARNING UNTIL 7 PM EST THIS EVENING FOR NJZ001. FLOOD WATCH THROUGH THIS EVENING FOR NJZ012-013-015>019. WINTER STORM WARNING UNTIL NOON EST TODAY FOR NJZ007. DE...ICE STORM WARNING UNTIL 10 AM EST THIS MORNING FOR DEZ001. FLOOD WATCH THROUGH THIS EVENING FOR DEZ001. MD...ICE STORM WARNING UNTIL 10 AM EST THIS MORNING FOR MDZ008-012. FLOOD WATCH THROUGH THIS EVENING FOR MDZ008. MARINE...GALE WARNING UNTIL 12 PM EST THURSDAY FOR ANZ430-431-450>455. && $$ SHORT TERM/LONG TERM...OHARA AVIATION/MARINE/TIDES...IOVINO
AREA FORECAST DISCUSSION...UPDATED
NWS MOUNT HOLLY NJ
213 AM EST WED FEB 14 2007 .SHORT TERM /REST OF TONIGHT/... RADAR MOSAIC SHOWING A LARGE AREA OF PRECIPITATION ABOUT TO OVERSPREAD THE AREA. COLD AIR HOLDING TOUGH ALONG THE I-95 CORRIDOR AND ACARS SOUNDING SHOWING FREEZING RAIN SOUNDING AT KPHL RECENTLY. DECIDED TO RAISE ICE STORM WARNING FLAG...AS A SIGNIFICANT PERIOD OF FREEZING RAIN AND SLEET APPEAR IMMINENT. ICE ACCUMULATIONS OF 1/4 TO 1/2 INCH LIKELY. && .PHI WATCHES/WARNINGS/ADVISORIES... PA...ICE STORM WARNING UNTIL 10 AM EST THIS MORNING FOR PAZ067>071. COASTAL FLOOD ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR PAZ069>071. FLOOD WATCH FROM 9 AM EST THIS MORNING THROUGH THIS EVENING FOR PAZ070-071. WINTER STORM WARNING UNTIL NOON EST TODAY FOR PAZ060>062. WINTER STORM WARNING UNTIL 7 PM EST THIS EVENING FOR PAZ054- 055. NJ...ICE STORM WARNING UNTIL 10 AM EST THIS MORNING FOR NJZ008>010- 012-013-015>019. COASTAL FLOOD ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR NJZ012>014-016>027. FLOOD WATCH FROM 9 AM EST THIS MORNING THROUGH THIS EVENING FOR NJZ012-013-015>019. WINTER STORM WARNING UNTIL NOON EST TODAY FOR NJZ007. WINTER STORM WARNING UNTIL 7 PM EST THIS EVENING FOR NJZ001. DE...ICE STORM WARNING UNTIL 10 AM EST THIS MORNING FOR DEZ001. COASTAL FLOOD ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR DEZ001>004. FLOOD WATCH FROM 9 AM EST THIS MORNING THROUGH THIS EVENING FOR DEZ001. MD...ICE STORM WARNING UNTIL 10 AM EST THIS MORNING FOR MDZ008-012. FLOOD WATCH FROM 9 AM EST THIS MORNING THROUGH THIS EVENING FOR MDZ008. WINTER WEATHER ADVISORY UNTIL 7 AM EST THIS MORNING FOR MDZ015- 019-020. MARINE...GALE WARNING UNTIL 7 AM EST THURSDAY FOR ANZ430-431-450>455. && $$ SHORT TERM... LONG TERM... AVIATION... MARINE...
AREA FORECAST DISCUSSION...UPDATED
NWS MOUNT HOLLY NJ
1250 AM EST WED FEB 14 2007 .AVIATION /06Z-06Z/... FOR KPHL, WE`VE KEPT IFR CEILINGS FOR THE BALANCE OF THE OVERNIGHT AND WEDNESDAY MORNING. CEILINGS MAY IMPROVE SLIGHTLY, PERHAPS TO 1000 OR 1500 FEET FOR THIS AFTERNOON AND EVENING AS THE WIND BACKS TO THE NORTHWEST. VSBY VALUES SHOULD BOUNCE FROM MVFR TO IFR AT LEAST THROUGH MID AFTERNOON AS PRECIP RATES VARY. THE SIGNIFICANT CHANGE TO THE FORECAST AT 06Z FOR KPHL, AS WELL AS FOR KILG, KPNE AND KTTN, IT TO KEEP TEMPS AT OR BELOW FREEZING THROUGHOUT THE ENTIRE EVENT. THE MESSAGE FROM MOST OF THE LATEST GUIDANCE IS THAT THE COLD AIR WILL NOT MIX OUT OF THOSE LOCATIONS. RECENT ACARS DATA INDICATE THAT THE FREEZING LEVEL WAS AROUND 3500 FEET AROUND MIDNIGHT OVER KPHL AND VCNTY. QUITE A DEEP LAYER OF COLD AIR TO ERODE WHILE FIGHTING A NORTHEAST SURFACE WIND THAT IS REINFORCING THE COLD AIR AT THE SURFACE. MORE OF A MIX OF FROZEN PRECIP IS ANTICIPATED FOR KABE AND KRDG FOR THE ENTIRE EVENT. MEANWHILE, KMIV AND KACY WILL BENEFIT FROM A LITTLE WARMING AND THEY SHOULD BE MOSTLY RAIN THROUGH MIDDAY, WITH A CHANGE TO SNOW AND SLEET THIS AFTERNOON AT THE TAIL END OF THE EVENT. BASED ON RADAR DATA AND GUIDANCE, WE`RE EXPECTING THE HEAVIEST PRECIP AT OUR EIGHT TAF SITES TO FALL MAINLY BETWEEN 09Z AND 15Z. && .PHI WATCHES/WARNINGS/ADVISORIES... PA...WINTER STORM WARNING UNTIL NOON EST TODAY FOR PAZ060>062- 067>069. COASTAL FLOOD ADVISORY FROM 4 AM EARLY THIS MORNING TO 1 PM EST THIS AFTERNOON FOR PAZ069>071. FLOOD WATCH FROM 9 AM EST THIS MORNING THROUGH THIS EVENING FOR PAZ070-071. WINTER WEATHER ADVISORY UNTIL 9 AM EST THIS MORNING FOR PAZ070- 071. WINTER STORM WARNING UNTIL 7 PM EST THIS EVENING FOR PAZ054- 055. NJ...WINTER STORM WARNING UNTIL NOON EST TODAY FOR NJZ007>010. WINTER WEATHER ADVISORY UNTIL 7 AM EST THIS MORNING FOR NJZ014- 020>022-026-027. COASTAL FLOOD ADVISORY FROM 4 AM EARLY THIS MORNING TO 1 PM EST THIS AFTERNOON FOR NJZ012>014-016>027. FLOOD WATCH FROM 9 AM EST THIS MORNING THROUGH THIS EVENING FOR NJZ012-013-015>019. WINTER WEATHER ADVISORY UNTIL 9 AM EST THIS MORNING FOR NJZ012- 013-015>019. WINTER STORM WARNING UNTIL 7 PM EST THIS EVENING FOR NJZ001. DE...WINTER WEATHER ADVISORY UNTIL 7 AM EST THIS MORNING FOR DEZ002. COASTAL FLOOD ADVISORY FROM 4 AM EARLY THIS MORNING TO 1 PM EST THIS AFTERNOON FOR DEZ001>004. FLOOD WATCH FROM 9 AM EST THIS MORNING THROUGH THIS EVENING FOR DEZ001. WINTER WEATHER ADVISORY UNTIL 9 AM EST THIS MORNING FOR DEZ001. MD...WINTER WEATHER ADVISORY UNTIL 7 AM EST THIS MORNING FOR MDZ015- 019-020. FLOOD WATCH FROM 9 AM EST THIS MORNING THROUGH THIS EVENING FOR MDZ008. WINTER WEATHER ADVISORY UNTIL 9 AM EST THIS MORNING FOR MDZ008- 012. MARINE...GALE WARNING UNTIL 7 AM EST THURSDAY FOR ANZ430-431-450>455. && $$ AVIATION UPDATE...IOVINO
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
640 PM EST THU FEB 15 2007 .AVIATION... LAKE EFFECT SNOW SHOWERS SHOULD CONTINUE TO TRANSLATE EAST OF SBN AND FWA AND WEAKEN EARLY THIS AFTERNOON. SKIES SHOULD BECOME CLEAR TO PARTLY CLOUDY SKIES AS HIGH PRESSURE BUILDS INTO THE AREA. && .SHORT TERM... TONIGHT AND FRIDAY...HAVE ISSUED A WIND CHILL ADVISORY FOR MUCH OF NORTHERN INDIANA AND NORTHWEST OHIO...EXCEPT FOR AREAS NEAR THE MICHIGAN STATE LINE. THE CORE OF ARCTIC AIR IS EXPECTED TO MOVE ACROSS THE AREA TONIGHT AS SKIES BECOME CLEAR/MOSTLY CLEAR EXCEPT FOR FAR SOUTHERN LOWER MICHIGAN AND BORDERING AREAS TO THE SOUTH. PER ACARS/TAMDAR OBS...NAM/WRF HAS INITIALIZED THE UPSTREAM CORE WELL WITH 925 MB TEMPS BETWEEN -18C AND -19C...WHICH WAS EVEN COLDER THAN THE AIRMASS OVER THE AREA THIS MORNING WHEN FWA...DFI AND GUS DROPPED TO BETWEEN -8F AND -12F. SNOW DEPTHS STILL 8 INCHES TO CLOSE TO 2 FEET OVER THE SOUTHERN HALF OF THE AREA...SOUTH OF HIGHWAY 6...AND SUFFICIENT FOR EVEN RECORD COLD LOWS IF CONDITIONS ARE RIGHT. WINDS SHOULD STAY UP ENOUGH TO CAUSE WIND CHILL TEMPERATURES TO FALL TO BETWEEN -20F AND -25F TONIGHT INTO FRIDAY MORNING. NCEP GFS/MAV AND NGM/FWC MOS NOT HANDLING LOWS VERY WELL...POSTING A LARGE WARM BIAS OF AS MUCH AS 17F. NEEDLESS TO SAY...CUT MOS TEMPS SIGNIFICANTLY. CONDITIONS WILL STILL BE CHILLY FRIDAY MORNING AS RETURN FLOW INCREASES...BUT WARM AIR ADVECTION JUST BEGINNING. && .LONG TERM... FRIDAY NIGHT THROUGH THURSDAY. UPR LVL WEATHER PATTERN OVER THE UNITED STATES AND CANADA WILL UNDERGO A PATTERN SHIFT DURING THE EXTENDED PERIOD. COLD POLAR VORTEX LOCATED OVER SE CANADA AND PREDOMINATE NORTHWEST FLOW WILL GRADUALLY WEAKEN AND SHIFT NORTHWARD BY EARLY NEXT WEEK. IN THE MEANTIME...THERE WILL BE A CLIPPER SYSTEM TO CONTEND WITH IN THE IMMEDIATE LONG TERM PERIOD...AS WELL AS ANOTHER ROUND OF LAKE EFFECT SNOW IN ITS WAKE. PREFER THE 12Z GFS VERSUS THE NAM-WRF IN REGARDS TO THE UPCOMING CLIPPER SYSTEM AND WILL THUS USE CLOSELY. MID LVL S/WV WAS PUSHING ONSHORE ACRS BRITISH COLUMBIA THIS AFTN. THIS FEATURE WILL DIVE RAPIDLY SE INTO THE NRN PLAINS ON FRIDAY...THEN IT WILL HEAD TOWARD THE WRN GREAT LAKES/LOWER OHIO VALLEY FRIDAY NIGHT. DECENT ISENTROPIC LIFT/WAA AHEAD OF THE CLIPPER WILL BRING A SWATH OF SNOW TO THE REGION...BEGINNING FRIDAY EVENING AND CONTINUING INTO SATURDAY MORNING. THERE WILL ALSO BE SOME DYNAMICAL LIFT WITH THE UPR LVL S/WV...AIDING IN UPWARD VERTICAL MOTION. THE MODIFIED GARCIA METHOD AND MODEL QPF INDICATE THAT 2 TO 4 INCHES OF SNOW WILL FALL ACROSS THE REGION FROM FRIDAY NIGHT INTO SATURDAY MORNING. AS THE CLIPPER PASSES TO THE SE BY SATURDAY AFTERNOON...SNOW WILL TAPER OFF. TEMPERATURES FRIDAY NIGHT WILL BE NON DIURNAL AS WAA AND WINDS FROM THE SOUTH/SOUTHWEST ALLOW TEMPS TO RISE SLOWLY TOWARD SATURDAY MORNING. THUS...WILL GO WITH AN EARLY EVENING LOW IN THE MID TEENS WITH TEMPS WARMING TO THE UPPER TEENS TO LOWER 20S BY SATURDAY MORNING. HIGHS ON SATURDAY WILL WARM INTO THE UPPER 20S. FOR SATURDAY NIGHT INTO SUNDAY NIGHT...ONE MORE S/WV WILL DIVE SE OUT OF CENTRAL CANADA INTO THE GREAT LAKES REGION. THIS FEATURE WILL BRING A BRIEF REINFORCING SHOT OF ARCTIC AIR. THE COLD AIR MOVING ACRS THE RELATIVELY WARMER WATERS OF LAKE MICHIGAN WILL GENERATE LAKE EFFECT SNOW SHOWERS. CURRENT FORECAST FETCH OF 300 TO 320 IS EXPECTED. HAVE MAINTAINED CURRENT HIGH CHC POPS IN THE FAVORED LAKE EFFECT COUNTIES FOR SATURDAY NIGHT...AND HAVE EXTENDED THE HIGH CHC INTO SUNDAY. LAKE EFFECT SNOW SHOWERS WILL DIMINISH QUICKLY SUNDAY NIGHT AS A RIDGE OF HIGH PRESSURE BUILDS TOWARD THE REGION. TEMPERATURES WILL REMAIN MUCH BELOW NORMAL DURING THIS PERIOD. AS STATED BEFORE...A PATTERN SHIFT IS IN THE OFFING FOR NEXT WEEK. S/WV ACTIVITY WILL COME ONSHORE ACRS THE WEST COAST...AND WILL TAKE A SRN TRAJECTORY ACRS THE SRN UNITED STATES. MEANWHILE...SOME S/WV ENERGY IN THE NRN JET STREAM (A SPLIT FLOW PATTERN) WILL PUSH A COLD FRONT THROUGH THE REGION TUESDAY/TUESDAY NIGHT. MODELS HAVE BEEN INCONSISTENT WITH THE SRN STREAM S/WV ENERGY...OSCILLATING ITS POSITION FROM RUN TO RUN. THE PATTERN THIS WINTER HAS BEEN TO TAKE THESE SRN STREAM S/WVS END FARTHER NORTH THAN FORECAST. MUCH UNCERTAINTY AT THIS POINT...SO WILL WAIT TO SEE HOW THIS ONE PANS OUT. IN THE MEANTIME...WILL JUST FOCUS ON THE NRN STREAM S/WV AND ASSOCD COLD FRONT TUESDAY/TUESDAY NIGHT. PCPN TYPE WILL BE A CONCERN AS TEMPS WILL WARM TO SLIGHTLY ABOVE FREEZING. WILL GO WITH A CHC OF RAIN OR SNOW ON TUESDAY...WITH A CHC OF SNOW TUESDAY NIGHT IN THE WAKE OF THE FRONT. HIGH PRESSURE IS FCST SETTLE ACRS THE FCST REGION WEDNESDAY AND THURSDAY. WILL FCST PARTLY CLOUDY SKIES WITH TEMPS AT OR SLIGHTLY ABOVE NORMAL. && .IWX WATCHES/WARNINGS/ADVISORIES... IN...WIND CHILL ADVISORY FROM 10 PM EST /9 PM CST/ THIS EVENING TO 11 AM EST /10 AM CST/ FRIDAY FOR INZ008-009-012>018-020- 022>027-032>034. MI...NONE. OH...WIND CHILL ADVISORY FROM 10 PM THIS EVENING TO 11 AM EST FRIDAY FOR OHZ004-005-015-016-024-025. LM...SMALL CRAFT ADVISORY UNTIL 7 PM EST FRIDAY FOR LMZ043-046. && $$ SHORT TERM/AVIATION...SKIPPER LONG TERM....HICKMAN
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
1000 PM EST THU FEB 15 2007 .UPDATE... MID/UPR LEVEL CIRCULATION SEEN ON WATER VAPOR IMAGERY TRACKING SEWD INTO NRN AR ATTM...PUSHING SCT MID/HI LEVEL CLDS PRIMARILY OVER DOWNSTATE KY. ACRS THE NRN HALF OF OUR FA...EXPECT JUST SOME CI OVRNGT...SO MOCLR N TO PCLDY SKIES S WILL PREVAIL. NAM HAS BACKED OFF LO STRATUS DEVELOPMENT IT WAS SHOWING WITH THE 18Z RUN...AS INDICATED BY ITS FCST 00Z SOUNDINGS. DID NOT CHG TEMPS MUCH OVERNIGHT...WILL LEAVE WIND CHILLS HIGHLIGHTED IN THE HWO WITH THE COMBO OF TEMPS/WINDS NOT QUITE AS COLD PER WIND CHILLS AS PRVS FCST...AROUND -5 FAR N AND +5 FAR S...BOTTOMING OUT ARND 10Z. DK .SHORT TERM (TONIGHT-FRIDAY)... MAIN FOCUS IN THE SHORT TERM WILL BE OVER THE NEXT 6-9 HOURS. RADAR SHOWING SOMEWHAT WIDESPREAD FLURRY OR -SHSN ACTIVITY DEVELOPING FROM ROUGHLY HOP-SDF-CVG AS OF 18Z. LAPSE RATES ARE VERY STEEP ON LATEST ACARS SOUNDINGS AT SDF (THROUGH THE -15C LEVEL)...BUT LOW LEVELS ARE QUITE DRY. BEST CHANCES FOR -SHSN WILL BE ALONG RELATIVE MAX IN SFC DEWPOINTS...WHICH CURRENTLY STRETCHES FROM WRN KY UP INTO THE SDF-CVG CORRIDOR. GFS LOW LEVEL RH FIELDS PICK UP ON THIS ENHANCED CLOUDINESS AT THE 900/925MB LEVELS...AND TRANSLATE FEATURE SE INTO OUR ERN COUNTIES BY 22-00Z THIS EVENING...AND OUT OF THE CWA SHORTLY THEREAFTER. WILL INCLUDE A "LATE AFTERNOON" PERIOD IN THE ZONES FOR ISLTD -SHSN. NOT EXPECTING ANY ACCUMS OTHER THAN TRACE GIVEN THE RELATIVELY DRY LOW LEVELS. CLOUD COVER TONIGHT WILL PRESENT A CHALLENGE...WITH NAM DEVELOPING WIDESPREAD LOW STRATUS WHILE GFS IS SIGNIFICANTLY DRIER IN THE LOW LEVELS. FEEL THAT NAM IS OVERDEVELOPING LOW STRATUS THIS AFTN OVER THE SNOW FIELDS NORTH OF THE CWA...WHICH IS SEEN IN THE 6-9HR VERIFICATIONS OF THE 12Z RUN...SO WILL SIDE WITH GFS. WILL STILL MAINTAIN AT LEAST 30% CLOUD COVER OVERNIGHT WITH BANDS OF MID/HIGH LEVEL CLOUDS PASSING THROUGH. LOWS TONIGHT WILL BE VERY COLD OVER THE N 1/3 OF THE DISTRICT...MID-UPPER SINGLE DIGITS. WIND CHILLS WILL LIKELY DROP INTO THE -5 TO -10F RANGE BY DAYBREAK...SO WILL HIGHLIGHT THIS IN HAZ WX OUTLOOK SINCE IT IS BORDERLINE ADVISORY CRITERIA. OVER SRN KY...WCI VALUES SHOULD BE WARMER (~ZERO TO 5 ABOVE). SIG WX NIL DURING THE DAYLIGHT HOURS FRIDAY WITH LOW LEVEL FLOW TURNING MORE SOUTHERLY TOWARD LATE AFTN AHEAD OF APPROACHING CLIPPER. SIGNIFICANT THERMAL TROF REMAINS OVER THE CWA...AND EVEN WITH EXPECTED SUNSHINE...TEMPS WILL ONLY BE A FEW DEGREES WARMER THAN TODAY. CS .LONG TERM (FRIDAY NIGHT-THURSDAY)... ...CLIPPER SYSTEM TO BRING A PERIOD OF SNOW TO THE REGION LATE FRIDAY AND SATURDAY... FRIDAY NIGHT THROUGH SUNDAY NIGHT... OVERALL...SHORT TERM MODEL SOLUTIONS ARE COMING INTO SOMEWHAT BETTER AGREEMENT WITH THIS WEEKENDS CLIPPER SYSTEM. 12Z NAM-WRF AND GFS CONTINUE TO SHOW UPPER LEVEL WAVE AND ASSOCIATED SFC LOW TRACKING SOUTHEAST TOWARD THE OHIO VALLEY. THOUGH AS THE SFC LOW GETS HERE...IT WILL BE WEAKENING. GFS AND NAM CONTINUE TO DIFFER ON THE FORECAST TRACK OF THE SYSTEM WITH THE NAM TAKING THE LOW NORTH OF THE RIVER WITH THE GFS A BIT FURTHER SOUTH. THE GFS TIMING IS FASTER THAN THE NAM WHICH WOULD KEEP MUCH OF THE HEAVIEST PRECIPITATION FALLING DURING THE DAY ON SATURDAY. THERMAL PROFILES HAVE TRENDED COLDER OVER THE LAST FEW RUNS AND OVERALL PROFILES SUGGEST SNOW AS THE PREDOMINANT PRECIPITATION. MAIN FORECAST CHALLENGE HERE WHAT WILL BE THE OVERALL TRACK OF THE SYSTEM. SO FAR THIS SEASON...THE NAM HAS OUTPERFORMED THE GFS SOLUTION HANDS DOWN. THE QPF VALUES HAVE BEEN MORE REALISTIC AS WELL AS THE THERMAL PROFILES. THE GFS HAS ALSO TENDED TO BE COLDER AND MORE WET IN TERMS OF QPF. AT THIS TIME...I THINK THE BEST APPROACH WOULD BE TO GO WITH A BLEND OF BOTH MODELS BUT CLOSER TO THE NAM SOLUTION. QPF AMOUNTS THROUGH THE ENTIRE EVENT WILL BE LESS THAN 0.25 INCHES AND WITH EXPECTED WARMTH IN THE PBL DURING THE DAY ON SATURDAY...SNOW RATIOS WILL BE CLOSE TO CLIMO WHICH IS 12:1. SNOW AMOUNTS FROM THE NAM WOULD SUGGEST 1-2 INCHES WHILE THE GFS SUGGESTS 2-4 INCHES. FOR NOW WILL PLAN ON A GENERAL 1-3...BUT MOST LOCATIONS WOULD LIKELY SEE 1-2 INCHES. IF THE SYSTEM TRENDS FURTHER NORTH...LESS SNOW IS LIKELY. TEMPERATURES SATURDAY WILL START OFF COLD WITH OVERNIGHT LOWS IN THE UPPER TEENS TO THE LOWER 20S. STUCK CLOSER THE THE 2M GFS NUMBERS FOR SATURDAY AFTERNOON WITH HIGHS IN THE UPPER 20S TO AROUND 32. AS CLIPPER SYSTEM MOVES EAST...DEEP NORTHWEST FLOW WILL CONTINUE ACROSS THE REGION. WEAK STATIC STABILITY AND LEFT OVER MOISTURE WILL LIKELY PRODUCE SCT SNOW SHOWERS DURING THE DAY ON SUNDAY ACROSS THE NORTHEAST THIRD OF THE FA. FOR THAT REASON HAVE OPTED TO KEEP LOW CHC POPS IN THE FORECAST HERE. TEMPERATURES WILL REMAIN WELL BELOW NORMAL WITH HIGHS IN THE LOW TO MID 20S IN THE NORTH TO THE UPPER 20S IN THE SOUTH. AS HIGH PRESSURE BUILDS IN...SKIES SHOULD CLEAR OUT SUNDAY NIGHT AND TEMPS WILL RAPIDLY COOL. TEMPS MONDAY MORNING WILL BE HIGHLY DEPENDENT ON SNOW COVER. SINCE WE FEEL WE`LL HAVE SOME SNOW ON THE GROUND...LOWS IN THE UPPER SINGLE DIGITS WILL BE POSSIBLE ACROSS THE NORTHEAST SECTIONS WITH MID TEENS ACROSS THE SOUTHWEST. MONDAY THROUGH THURSDAY... EXTENDED MODEL SOLUTIONS CONTINUE TO SHOW A GENERAL MODERATION IN TEMPERATURES OVER THE UPCOMING WEEK. SFC HIGH PRESSURE IS FORECAST TO MOVE EAST OF THE REGION BY LATE MONDAY ALLOWING DEEP SOUTHWESTERLY FLOW TO RETURN TO THE REGION. COMBINATION OF DEEP SW FLOW COMING OFF THE GULF SHOULD RESULT IN SOME SCT LIGHT PRECIPITATION BY TUESDAY. INITIAL PRECIP MAY BE MIXED OR SNOW...BUT WOULD QUICKLY CHANGE TO RAIN AS TEMPS WARM. 00Z GFS ENSEMBLE SOLUTIONS SUPPORT THIS AND CURRENT FCST HAS THIS COVERED WELL. LATEST 12Z GFS HAS TRENDED MORE SOUTHERLY WITH SFC CYCLONE GOING ACROSS THE GULF COAST STATES. THIS IS IN STARK CONTRAST TO THE 06Z GFS RUN. GIVEN THE RATHER POOR RUN TO RUN CONSISTENCY GENERALLY PLAN ON STICKING CLOSE TO THE 00Z GFS ENSEMBLE PACKAGE FOR THIS PERIOD. ENSEMBLE PACKAGE IS A BIT FURTHER NORTH WITH SFC LOW GOING ACROSS THE SOUTHERN STATES. NET RESULT IS A CHANCE OF PRECIPITATION ON WEDNESDAY WITH DRIER CONDITIONS RETURNING BY THU. THERMAL PROFILES SUGGEST PRECIP ON WED WILL BE RAIN AS OVERALL ARCTIC PATTERN LOOSES ITS GRIP ON THE EASTERN THIRD OF THE COUNTRY. -MJ .AVIATION...(00Z TAFS)... VFR THRU THE PD. LIGHT NLY FLO WILL GIVE WAY TO INCREASING SW FLO FRI AS A RIDGE OF HI PRES MOVES ACRS OUR FA TNGT AND EARLY FRI. BY LATE IN THE PD...RIDGE WILL BE POSITIONED ACRS FAR EKY RESULTING IN A SW RETURN FLO. CIGS ARND 040 IN THE LEX VCNTY WILL BECOME SCT BY 03Z. && .LMK WATCHES/WARNINGS/ADVISORIES... KY...NONE. IN...NONE. && $$
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
625 PM EST THU FEB 15 2007 .AVIATION...(00Z TAFS)... VFR THRU THE PD. LIGHT NLY FLO WILL GIVE WAY TO INCREASING SW FLO FRI AS A RIDGE OF HI PRES MOVES ACRS OUR FA TNGT AND EARLY FRI. BY LATE IN THE PD...RIDGE WILL BE POSITIONED ACRS FAR EKY RESULTING IN A SW RETURN FLO. CIGS ARND 040 IN THE LEX VCNTY WILL BECOME SCT BY 03Z. .SHORT TERM (TONIGHT-FRIDAY)... MAIN FOCUS IN THE SHORT TERM WILL BE OVER THE NEXT 6-9 HOURS. RADAR SHOWING SOMEWHAT WIDESPREAD FLURRY OR -SHSN ACTIVITY DEVELOPING FROM ROUGHLY HOP-SDF-CVG AS OF 18Z. LAPSE RATES ARE VERY STEEP ON LATEST ACARS SOUNDINGS AT SDF (THROUGH THE -15C LEVEL)...BUT LOW LEVELS ARE QUITE DRY. BEST CHANCES FOR -SHSN WILL BE ALONG RELATIVE MAX IN SFC DEWPOINTS...WHICH CURRENTLY STRETCHES FROM WRN KY UP INTO THE SDF-CVG CORRIDOR. GFS LOW LEVEL RH FIELDS PICK UP ON THIS ENHANCED CLOUDINESS AT THE 900/925MB LEVELS...AND TRANSLATE FEATURE SE INTO OUR ERN COUNTIES BY 22-00Z THIS EVENING...AND OUT OF THE CWA SHORTLY THEREAFTER. WILL INCLUDE A "LATE AFTERNOON" PERIOD IN THE ZONES FOR ISLTD -SHSN. NOT EXPECTING ANY ACCUMS OTHER THAN TRACE GIVEN THE RELATIVELY DRY LOW LEVELS. CLOUD COVER TONIGHT WILL PRESENT A CHALLENGE...WITH NAM DEVELOPING WIDESPREAD LOW STRATUS WHILE GFS IS SIGNIFICANTLY DRIER IN THE LOW LEVELS. FEEL THAT NAM IS OVERDEVELOPING LOW STRATUS THIS AFTN OVER THE SNOW FIELDS NORTH OF THE CWA...WHICH IS SEEN IN THE 6-9HR VERIFICATIONS OF THE 12Z RUN...SO WILL SIDE WITH GFS. WILL STILL MAINTAIN AT LEAST 30% CLOUD COVER OVERNIGHT WITH BANDS OF MID/HIGH LEVEL CLOUDS PASSING THROUGH. LOWS TONIGHT WILL BE VERY COLD OVER THE N 1/3 OF THE DISTRICT...MID-UPPER SINGLE DIGITS. WIND CHILLS WILL LIKELY DROP INTO THE -5 TO -10F RANGE BY DAYBREAK...SO WILL HIGHLIGHT THIS IN HAZ WX OUTLOOK SINCE IT IS BORDERLINE ADVISORY CRITERIA. OVER SRN KY...WCI VALUES SHOULD BE WARMER (~ZERO TO 5 ABOVE). SIG WX NIL DURING THE DAYLIGHT HOURS FRIDAY WITH LOW LEVEL FLOW TURNING MORE SOUTHERLY TOWARD LATE AFTN AHEAD OF APPROACHING CLIPPER. SIGNIFICANT THERMAL TROF REMAINS OVER THE CWA...AND EVEN WITH EXPECTED SUNSHINE...TEMPS WILL ONLY BE A FEW DEGREES WARMER THAN TODAY. CS .LONG TERM (FRIDAY NIGHT-THURSDAY)... ...CLIPPER SYSTEM TO BRING A PERIOD OF SNOW TO THE REGION LATE FRIDAY AND SATURDAY... FRIDAY NIGHT THROUGH SUNDAY NIGHT... OVERALL...SHORT TERM MODEL SOLUTIONS ARE COMING INTO SOMEWHAT BETTER AGREEMENT WITH THIS WEEKENDS CLIPPER SYSTEM. 12Z NAM-WRF AND GFS CONTINUE TO SHOW UPPER LEVEL WAVE AND ASSOCIATED SFC LOW TRACKING SOUTHEAST TOWARD THE OHIO VALLEY. THOUGH AS THE SFC LOW GETS HERE...IT WILL BE WEAKENING. GFS AND NAM CONTINUE TO DIFFER ON THE FORECAST TRACK OF THE SYSTEM WITH THE NAM TAKING THE LOW NORTH OF THE RIVER WITH THE GFS A BIT FURTHER SOUTH. THE GFS TIMING IS FASTER THAN THE NAM WHICH WOULD KEEP MUCH OF THE HEAVIEST PRECIPITATION FALLING DURING THE DAY ON SATURDAY. THERMAL PROFILES HAVE TRENDED COLDER OVER THE LAST FEW RUNS AND OVERALL PROFILES SUGGEST SNOW AS THE PREDOMINANT PRECIPITATION. MAIN FORECAST CHALLENGE HERE WHAT WILL BE THE OVERALL TRACK OF THE SYSTEM. SO FAR THIS SEASON...THE NAM HAS OUTPERFORMED THE GFS SOLUTION HANDS DOWN. THE QPF VALUES HAVE BEEN MORE REALISTIC AS WELL AS THE THERMAL PROFILES. THE GFS HAS ALSO TENDED TO BE COLDER AND MORE WET IN TERMS OF QPF. AT THIS TIME...I THINK THE BEST APPROACH WOULD BE TO GO WITH A BLEND OF BOTH MODELS BUT CLOSER TO THE NAM SOLUTION. QPF AMOUNTS THROUGH THE ENTIRE EVENT WILL BE LESS THAN 0.25 INCHES AND WITH EXPECTED WARMTH IN THE PBL DURING THE DAY ON SATURDAY...SNOW RATIOS WILL BE CLOSE TO CLIMO WHICH IS 12:1. SNOW AMOUNTS FROM THE NAM WOULD SUGGEST 1-2 INCHES WHILE THE GFS SUGGESTS 2-4 INCHES. FOR NOW WILL PLAN ON A GENERAL 1-3...BUT MOST LOCATIONS WOULD LIKELY SEE 1-2 INCHES. IF THE SYSTEM TRENDS FURTHER NORTH...LESS SNOW IS LIKELY. TEMPERATURES SATURDAY WILL START OFF COLD WITH OVERNIGHT LOWS IN THE UPPER TEENS TO THE LOWER 20S. STUCK CLOSER THE THE 2M GFS NUMBERS FOR SATURDAY AFTERNOON WITH HIGHS IN THE UPPER 20S TO AROUND 32. AS CLIPPER SYSTEM MOVES EAST...DEEP NORTHWEST FLOW WILL CONTINUE ACROSS THE REGION. WEAK STATIC STABILITY AND LEFT OVER MOISTURE WILL LIKELY PRODUCE SCT SNOW SHOWERS DURING THE DAY ON SUNDAY ACROSS THE NORTHEAST THIRD OF THE FA. FOR THAT REASON HAVE OPTED TO KEEP LOW CHC POPS IN THE FORECAST HERE. TEMPERATURES WILL REMAIN WELL BELOW NORMAL WITH HIGHS IN THE LOW TO MID 20S IN THE NORTH TO THE UPPER 20S IN THE SOUTH. AS HIGH PRESSURE BUILDS IN...SKIES SHOULD CLEAR OUT SUNDAY NIGHT AND TEMPS WILL RAPIDLY COOL. TEMPS MONDAY MORNING WILL BE HIGHLY DEPENDENT ON SNOW COVER. SINCE WE FEEL WE`LL HAVE SOME SNOW ON THE GROUND...LOWS IN THE UPPER SINGLE DIGITS WILL BE POSSIBLE ACROSS THE NORTHEAST SECTIONS WITH MID TEENS ACROSS THE SOUTHWEST. MONDAY THROUGH THURSDAY... EXTENDED MODEL SOLUTIONS CONTINUE TO SHOW A GENERAL MODERATION IN TEMPERATURES OVER THE UPCOMING WEEK. SFC HIGH PRESSURE IS FORECAST TO MOVE EAST OF THE REGION BY LATE MONDAY ALLOWING DEEP SOUTHWESTERLY FLOW TO RETURN TO THE REGION. COMBINATION OF DEEP SW FLOW COMING OFF THE GULF SHOULD RESULT IN SOME SCT LIGHT PRECIPITATION BY TUESDAY. INITIAL PRECIP MAY BE MIXED OR SNOW...BUT WOULD QUICKLY CHANGE TO RAIN AS TEMPS WARM. 00Z GFS ENSEMBLE SOLUTIONS SUPPORT THIS AND CURRENT FCST HAS THIS COVERED WELL. LATEST 12Z GFS HAS TRENDED MORE SOUTHERLY WITH SFC CYCLONE GOING ACROSS THE GULF COAST STATES. THIS IS IN STARK CONTRAST TO THE 06Z GFS RUN. GIVEN THE RATHER POOR RUN TO RUN CONSISTENCY GENERALLY PLAN ON STICKING CLOSE TO THE 00Z GFS ENSEMBLE PACKAGE FOR THIS PERIOD. ENSEMBLE PACKAGE IS A BIT FURTHER NORTH WITH SFC LOW GOING ACROSS THE SOUTHERN STATES. NET RESULT IS A CHANCE OF PRECIPITATION ON WEDNESDAY WITH DRIER CONDITIONS RETURNING BY THU. THERMAL PROFILES SUGGEST PRECIP ON WED WILL BE RAIN AS OVERALL ARCTIC PATTERN LOOSES ITS GRIP ON THE EASTERN THIRD OF THE COUNTRY. -MJ && .LMK WATCHES/WARNINGS/ADVISORIES... KY...NONE. IN...NONE. && $$
AREA FORECAST DISCUSSION
NWS BALTIMORE MD/WASHINGTON DC
928 AM EST WED FEB 14 2007 .SHORT TERM /REST OF TODAY/... QUITE THE STORM...XTNSV PNS LISTING SNOW/SLEET/FZRA RECENTLY ISSUED. THX TO ALL WHO CONTRIBUTED TO THIS PRODUCT. I`LL BE PULLING THE WINT STORM WRNG FOR ALL XCPT NERN MD...WL LV THAT IN EFFECT UNTIL NOON. 12Z SFC ANLYS SHOWS STRNG PRES GRAD TO OUR W WHICH WL BE MOVG INTO RGN THIS AFTN. STILL XPCTG GUSTY WINDS WHICH MAY DO ADTNL DAMAGE. I`LL BE LOOKING AT NEED FOR SOME SORT OF WIND PRODUCT FOR THE AFTN HRS. WOODY! && .PREV DISCUSSION... /ISSUED 440 AM EST WED FEB 14 2007/ SHORT TERM (TODAY)... ..SIGNIFICANT WINTER STORM AFFECTING THE REGION... WATER VAPOR LOOP SHOWS THE UPPER LEVEL REFLECTION OF THE WINTER STORM IS MOVING FROM THE NORTHERN MID ATLANTIC INTO NEW ENGLAND...WITH A SHORT WAVE TRAILING BEHIND ACROSS THE TENNESSEE VALLEY. ACARS 400-250MB WIND OBSERVATIONS SHOW A 100-140KT SOUTHWESTERLY JET ACROSS THE EASTERN GREAT LAKES...WITH A 120-160KT WESTERLY JET ACROSS NORTHERN MEXICO AND THE WESTERN COAST OF THE GULF OF MEXICO. 04Z SURFACE ANALYSIS PLACED A 1000MB PRIMARY CYCLONE ACROSS EASTERN KENTUCKY...WITH A COLD FRONT TRAILING SOUTHWEST THROUGH THE CENTRAL GULF OF MEXICO. A SECONDARY 1002MB CYCLONE HAD DEVELOPED ACROSS NORTH CAROLINA...WITH A COASTAL BOUNDARY EXTENDING NORTHEAST THROUGH NORFOLK AND EAST OF THE DELMARVA. CONVECTION HAS BEEN OCCURRING OFF THE MID ATLANTIC COAST. 06Z KIAD RAOB INDICATES COOLING LOW LEVELS COMPARED TO 0445Z KIAD ACARS SOUNDING. THIS IS DUE TO CONTINUED FUNNELING OF COLD AIR FROM NEW ENGLAND AS PRESSURE FALLS OF 9MB IN 3HR ARE OCCURRING ACROSS EASTERN VIRGINIA. OVERALL...THIS IS CONTRIBUTING TO MORE SLEET THAN FREEZING RAIN ACROSS THE CENTRAL FORECAST AREA. SIGNIFICANT ICING HAS BEEN REPORTED IN THE CENTRAL VIRGINIA FOOTHILLS...WITH AN INCH AND A HALF OF ICE...AND DOWNED LARGE TREES AND POWER LINES. WITH THE BULK OF PRECIPITATION ENDING IN CENTRAL VIRGINIA BEFORE SUNRISE...AND BALTIMORE DURING THE MID MORNING...THE WINTER STORM WARNING WAS ADJUSTED TO EXPIRE AT 15Z. WHILE THERE MAY BE AN HOUR OR SO OF FREEZING DRIZZLE ON THE BACKSIDE OF THE STEADY PRECIPITATION...EXPECTING MUCH OF THE REMAINDER OF THE MORNING TO BE PRECIPITATION FREE. SNOW SHOWERS ASSOCIATED WITH THE TENNESSEE VALLEY SHORT WAVE MAY AFFECT THE WESTERN AND NORTHERN FORECAST AREA DURING THE MIDDAY THROUGH MID AFTERNOON. LITTLE IN THE WAY OF SNOWFALL IS EXPECTED...EXCEPT IN FAVORED UPSLOPE AREAS IN THE MOUNTAINS. TEMPERATURES ARE TRICKY TODAY. MODELS DO NOT HAVE A GOOD GRIP ON THE CURRENT COLD WEDGE ACROSS THE REGION. HOWEVER...EXPERIENCE SUGGESTS THAT MIXING MAY OCCUR INTO THE THERMAL RIDGE ACROSS THE EASTERN FORECAST AREA THIS MORNING ON THE BACK SIDE OF THE STORM...BEFORE COLD ADVECTION SETS IN THIS AFTERNOON WITH THE PASSAGE OF THE SHORT WAVE. PRESSURE RISES OF 3-6MB PER 3 HOURS THIS AFTERNOON COINCIDENT WITH THE BEGINNING OF COLD ADVECTION WITH THE PASSAGE OF THE SHORT WAVE SUGGESTS MIXING OF HIGHER MOMENTUM AIR TO THE SURFACE. HELD OFF ON A WIND ADVISORY AS 00Z GFS/NAM BUFKIT FORECAST SOUNDINGS INDICATED WIND GUSTS ONLY BARELY GETTING TO 40KT. EXPERIENCE SUGGESTS TO GO A FEW KNOTS BELOW GUIDANCE DUE TO THE LEVEL OF SURFACE FRICTION. HOWEVER...ANY ICE BEARING TREES WILL HAVE A HIGHER PROBABILITY OF FALLING. THE NEXT SHIFT WILL REEVALUATE THE WIND ISSUE WITH THE EXPIRATION OF THE WINTER STORM WARNING. LONG TERM (TONIGHT THROUGH TUESDAY)... MODELS ARE IN GOOD AGREEMENT INDICATING A MID LEVEL VORT LOBE SWINGING EAST OF THE CWA THIS EVENING...ALLOWING NVA TO BUILD ACROSS THE MID ATLANTIC. NVA WILL SCOUR OUT THE CLOUDS...AND END ANY LINGERING LIGHT PRECIPITATION. THE EXCEPTION WILL BE IN FAVORED UPSLOPE AREAS WHERE FAVORED WIND TRAJECTORIES WILL PRODUCE SOME SNOW SHOWERS TONIGHT. COLD ADVECTION WILL BRING A COLDER AIR MASS ACROSS THE MID ATLANTIC...AND COLD ADVECTION COMBINED WITH A TIGHT GRADIENT AROUND LOW PRESSURE MOVING UP THE EAST COAST WILL HELP TO PRODUCE GUSTY WINDS OVERNIGHT. GFS 850 MB WINDS ARE FORECAST 40-50 KT...AND WITH COLD ADVECTION...A FAIR AMOUNT OF THIS WILL BE ABLE TO COME DOWN IN GUSTS. WILL HAVE TO WATCH FOR THE POTENTIAL OF WIND ADVISORY CRITERIA BEING MET OVER OUR WESTERN ZONES...ESPECIALLY OVER THE HIGHER ELEVATIONS. IN ADDITION...COLDER AIR COMBINED WITH GUSTY WINDS WILL LEAD TO WIND CHILL VALUES AOB -5 DEG F IN OUR WESTERN ZONES. THIS MEETS WIND CHILL ADVISORY CRITERIA...BUT SINCE THIS WILL OCCUR IN THE SECOND PERIOD AND SINCE WE HAVE OTHER WINTER HEADLINES ONGOING...WILL NOT ISSUE A WIND CHILL ADVISORY ATTM. UPSLOPE SNOW SHOWERS WILL LIKELY OCCUR THROUGH THE REST OF THE WEEK...AS W/NW WINDS REINFORCE THE COLD AIR. THE NEXT CHANCE FOR PRECIPITATION ACROSS THE ENTIRE CWA...WHICH WOULD OCCUR IN THE FORM OF SNOW...IS FORECAST OVER THE WEEKEND. GFS AND ECMWF EXHIBIT SOME TIMING DIFFERENCES...SO HAVE CONTINUED WITH CONTINUITY HIGHLIGHTING 20-30 POPS OVER THE WEEKEND WITH DRY YET CONTINUED BELOW CLIMATOLOGY TEMPERATURE CONDITIONS OCCURRING EARLY NEXT WEEK. AVIATION... IFR CEILINGS AND VISIBILITIES WILL PERSIST UNTIL THE STEADY PRECIPITATION ENDS DURING THE EARLY TO MID MORNING. MIXING HEIGHTS WILL DEEPEN THROUGH THE DAY WITH THE ARRIVAL OF COLD ADVECTION. THERE COULD BE SOME SNOW SHOWERS ASSOCIATED WITH THE SHORT WAVE PASSAGE THIS AFTERNOON...HOWEVER CONFIDENCE WAS NOT HIGH ENOUGH TO INCLUDE IN THE 06Z TERMINALS. WINDS WILL BE SHIFTING TO WNW AS THE CYCLONE MOVES TO THE NORTHEAST...WITH GUSTS OF 35KTS EXPECTED. EASTERLY WINDS GUSTING TO 40KT AT 2KFT WILL PRESENT LOW LEVEL WIND SHEAR UNTIL SURFACE WINDS SWING TO NORTHWEST. MARINE... 00Z MET/MAV MOS AT THOMAS POINT INDICATE SUSTAINED WINDS INCREASING TO 20-25KTS THIS AFTERNOON. PROXIMITY NAM/GFS BUFKIT FORECAST SOUNDINGS INDICATE UP TO A 40KT WIND GUST POTENTIAL THIS AFTERNOON. ICE COVERAGE ACROSS THE EXTREME NORTHERN BAY IS CLOSE TO 7-9 TENTHS. GALE CRITERIA IN GUSTS WILL BE MET TONIGHT THROUGH THURSDAY MORNING...BEFORE DROPPING TO SMALL CRAFT CRITERIA. SMALL CRAFT CALIBER SPEEDS MAY PERSIST THROUGH THE REST OF THE WEEK. && .LWX WATCHES/WARNINGS/ADVISORIES... DC...NONE. MD...WINTER WEATHER ADVISORY UNTIL 10 AM EST THIS MORNING FOR MDZ017-018. WINTER STORM WARNING UNTIL 1 PM EST THIS AFTERNOON FOR MDZ005>007-010-011-014. VA...NONE. WV...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL NOON EST TODAY FOR ANZ530>537. GALE WARNING UNTIL 7 AM EST THURSDAY FOR ANZ530>537. && $$ SHORT TERM...
AREA FORECAST DISCUSSION...UPDATED
NWS ALBUQUERQUE NM
900 PM MST THU FEB 15 2007 .UPDATE... ADDED MENTION OF PATCHY DENSE FOG OVERNIGHT TO ZNS 19 AND 26 BUT DONT EXPECT WIDESPREAD FOG TO PERSIST LONG ENOUGH IN ANY ONE AREA TO JUSTIFY A DENSE FOG ADVISORY. ADJUSTED WINDS EXPECTED IN THE NORTHEAST FRIDAY TO JUST UNDER WIND ADVISORY CRITERIA...STILL BREEZY TO WINDY NORTHEAST FRIDAY. 07 && .PREV DISCUSSION...259 PM MST THU FEB 15 2007 18Z SURFACE ANALYSIS SHOWS THE LAST VESTIGES OF A STATIONARY BOUNDARY DRAPED ALONG AND EAST OF THE CENTRAL MOUNTAIN CHAIN. LATEST WATER VAPOR LOOP SHOWS A WEST TO EAST ORIENTED MOISTURE PLUME PUSHING INTO THE PACIFIC NORTHWEST ALONG THE NORTHERN PERIPHERY OF A RIDGE BUILDING INTO CALIFORNIA. A DISORGANIZED UPPER LEVEL DISTURBANCE IS STATIONARY TO THE SOUTH WELL OFFSHORE BAJA CALIFORNIA. 400-250MB AIRCRAFT WIND DATA SHOWS A 90-110 KNOT JET OVER UTAH TRANSLATING EASTWARD AS THE RIDGE PUSHES EAST INTO CALIFORNIA. ONLY CONCERN IN THE SHORT TERM WILL BE WINDS TO THE LEE OF THE CENTRAL MOUNTAIN CHAIN FRIDAY. 12Z NAM BUFKIT PROFILE AT LAS VEGAS INDICATES ATMOSPHERE WILL BE PRIMED FOR STRONG MOUNTAIN WAVE DEVELOPMENT FRIDAY AS THE 90-110 KNOT OVER UTAH TRANSLATES TO THE EAST OF NEW MEXICO. NOT THINKING WINDS WILL BE ALL THAT WIDESPREAD WITH PROFILES INDICATING A DECENT CAPPING INVERSION CLOSE NEAR THE SURFACE...INHIBITING DOWNWARD MOMENTUM TRANSPORT. HOWEVER...THIS BEARS WATCHING AS 12Z METMOS GUIDANCE SHOWS SEVERAL HOURS OF 25-35 KNOT SUSTAINED WINDS AT CLINES CORNERS FRIDAY AFTERNOON. THE AMOUNT OF MIXING WILL ALSO BE COMPLICATED BY SNOW COVER PRESENT ALONG AND EAST OF THE CENTRAL MOUNTAINS. BEYOND FRIDAY...12Z MREF/15Z SREF GUIDANCE SHOWS THE AFOREMENTIONED RIDGE OVER CALIFORNIA BUILDING EASTWARD INTO THE SOUTHWEST CONUS AND CRESTING OVER NEW MEXICO SATURDAY INTO SUNDAY. 12Z GFS/NAM SOLUTIONS SHOW THE UPPER LEVEL DISTURBANCE CURRENTLY OFF THE BAJA WILL TRANSLATE ENERGY NORTHEAST TOWARD NEW MEXICO LATE SATURDAY AND SHEAR APART AS ANOTHER STRONGER TROUGH DIVES SOUTH ALONG THE CALIFORNIA COASTLINE SUNDAY. INCREASED CLOUD COVER AND LEFT A SLIGHT CHANCE OF PRECIP OVER THE SOUTHWEST MOUNTAINS AND UPPER GILA REGION EARLY SUNDAY AS THE FIRST PIECE OF ENERGY SHEARS NORTHEAST INTO NEW MEXICO AND HELPS SATURATE THE ATMOSPHERE AHEAD OF THE STRONGER UPPER LOW OVER SOUTHERN CALIFORNIA. CLOUD COVER AND CHANCE OF PRECIP WILL SLOWLY MOVE IN FROM WEST TO EAST ACROSS THE STATE WITH THE BEST CHANCES LATE MONDAY INTO TUESDAY. ANOTHER STRONGER RIDGE WILL BUILD INTO THE STATE BEHIND THIS SYSTEM BRINGING MORE TRANQUIL WEATHER TO THE STATE LATE NEXT WEEK. && .PRELIMINARY POINT TEMPS/POPS... FARMINGTON...................... 20 52 23 52 / 0 0 0 0 GALLUP.......................... 14 51 16 51 / 0 0 0 0 GRANTS.......................... 16 53 17 53 / 0 0 0 0 GLENWOOD........................ 27 63 31 65 / 0 0 0 0 CHAMA........................... -1 40 4 41 / 0 0 5 0 LOS ALAMOS...................... 15 46 16 45 / 0 0 0 0 RED RIVER....................... -3 37 8 37 / 0 0 0 0 TAOS............................ 6 44 9 44 / 0 0 0 0 SANTA FE........................ 12 47 19 47 / 0 0 0 0 SANTA FE AIRPORT................ 12 48 22 49 / 0 0 0 0 ESPANOLA........................ 17 50 20 50 / 0 0 5 0 ALBUQUERQUE HEIGHTS............. 22 50 28 53 / 0 0 0 0 ALBUQUERQUE VALLEY.............. 18 53 22 55 / 0 0 0 0 ALBUQUERQUE FOOTHILLS........... 19 48 24 51 / 0 0 0 0 ALBUQUERQUE WEST MESA........... 21 50 27 54 / 0 0 0 0 SOCORRO......................... 26 58 30 59 / 0 0 0 0 SANDIA PARK/CEDAR CREST......... 15 45 24 47 / 0 0 0 0 MORIARTY/ESTANCIA............... 4 47 22 46 / 0 0 0 0 CARRIZOZO....................... 23 56 29 59 / 0 0 0 0 RUIDOSO......................... 20 49 28 49 / 0 0 0 0 RATON........................... 12 52 18 47 / 0 0 0 0 LAS VEGAS....................... 15 50 22 49 / 0 0 0 0 ROY............................. 18 53 27 49 / 0 0 0 0 CLAYTON......................... 15 51 25 48 / 0 0 0 0 SANTA ROSA...................... 20 57 28 54 / 0 0 0 0 TUCUMCARI....................... 17 54 27 54 / 5 0 0 0 FORT SUMNER..................... 20 59 29 57 / 5 0 0 0 CLOVIS.......................... 18 58 29 54 / 5 0 0 0 PORTALES........................ 16 60 27 55 / 5 0 0 0 ROSWELL......................... 23 62 31 60 / 0 0 0 0 && .ABQ WATCHES/WARNINGS/ADVISORIES... NONE. && $$ GUYER
AREA FORECAST DISCUSSION...CORRECTED
NWS ALBUQUERQUE NM
248 PM MST WED FEB 14 2007 CORRECTION TO REMOVE ZONES 8 AND 9 FROM WINTER STORM WARNING .DISCUSSION... 18Z SURFACE ANALYSIS SHOWS A STATIONARY BOUNDARY DRAPED SOUTH TO NORTH ALONG THE CENTRAL MOUNTAIN CHAIN WITH A 1040MB HIGH PRES AREA BUILDING DOWN THE CENTRAL HIGH PLAINS INTO THE E PLAINS OF NM. LATEST WATER VAPOR LOOP SHOWS THE SOUTHERN STREAM SHEARED TROUGH AXIS OVER NM TRANSLATING EASTWARD AS A 150-170 KNOT JET SCREAMS EASTWARD INTO TEXAS OUT OF NORTHERN MEXICO...AS INDICATED BY 400-200MB AIRCRAFT WINDS. A NORTHERN STREAM UPPER TROUGH OVER THE CENTRAL HIGH PLAINS IS DROPPING SOUTH TOWARD THE FRONT RANGE. 12Z MREF/15Z SREF GUIDANCE IN GOOD AGREEMENT WITH THE 500MB HEIGHT PATTERN ON THE TIMING OF THE EXITING SOUTHERN STREAM TROUGH TONIGHT INTO THURSDAY AFTERNOON. 12Z NAM/GFS INDICATING SNOWFALL WILL EXIT THE FORECAST AREA WEST OF THE CENTRAL MTN CHAIN THIS EVENING BUT LINGER OVER THE SANGRES...ESTANCIA VALLEY...AND ESPECIALLY THE SACRAMENTO MOUNTAINS AND SOUTHEAST PLAINS THROUGH THURSDAY MORNING. INTERESTINGLY...BOTH MODELS SHOW AN AREA OF SNOW BLOSSOMING OVER THE NORTHERN MTNS THIS EVENING AND PRESSING SOUTH AND EAST THROUGH THE OVERNIGHT HOURS. LATEST IR SATELLITE IMAGERY LATE THIS AFTERNOON DOES INDEED SHOW CLOUD TOPS COOLING OVER SOUTH CENTRAL COLORADO. HPC SNOWFALL ACCUMULATION GRAPHICS ALSO INDICATE THE POTENTIAL FOR ANOTHER 1 TO 2 INCHES OF SNOWFALL OVER PORTIONS OF THE E PLAINS WITH 2 TO 4 INCHES IN THE SANGRES AND SACRAMENTO MTNS. DECIDED TO EXTEND HIGHLIGHTS EAST OF THE CENTRAL MTNS THRU 4AM THURSDAY EXCEPT THE FAR NE CORNER. 12Z NAM CROSS SECTION ALONG THE CENTRAL MTNS SHOWS DECENT LOW LEVEL VERTICAL VELOCITY ABOVE WEAK LOW LEVEL FRONTOGENESIS AND SATURATED EPV...SO CANNOT RULE OUT A FEW MORE INCHES OF SNOW FROM LIGHT TO MODERATE SNOW BANDS OVERNIGHT. EXPECT CLEARING SKIES ACROSS THE REMAINDER OF THE FORECAST WEST OF THE CENTRAL MTNS WITH VERY COLD TEMPS TONIGHT. WENT SEVERAL DEGREES BELOW MOS GUIDANCE EVERYWHERE. WILL ALSO ADD PATCHY FOG IN VALLEY AREAS. BEYOND THURSDAY...MODELS SHOWING A SLOW WARMING TREND WITH CLEAR TO PARTLY CLOUDY SKIES ACROSS THE STATE THROUGH THE WEEKEND AS A RIDGE BUILDS OVER THE SW CONUS. ANOTHER WEAK SOUTHERN STREAM SYSTEM TRIES TO MOVE NORTHEAST INTO THE RIDGE LATE SUNDAY...BUT THIS MAY BE MAINLY CLOUDS. && .PRELIMINARY POINT TEMPS/POPS... FARMINGTON...................... 19 42 22 50 / 0 0 0 0 GALLUP.......................... 10 40 13 46 / 0 0 0 0 GRANTS.......................... 9 39 11 43 / 5 0 0 0 GLENWOOD........................ 25 53 25 59 / 5 0 0 0 CHAMA........................... 1 30 -2 38 / 20 20 20 10 LOS ALAMOS...................... 10 34 15 42 / 20 0 0 5 RED RIVER....................... -1 24 -5 34 / 60 20 20 10 TAOS............................ 6 35 10 41 / 50 5 5 5 SANTA FE........................ 13 36 18 42 / 30 0 0 5 SANTA FE AIRPORT................ 15 37 19 43 / 20 0 0 0 ESPANOLA........................ 17 40 22 48 / 20 0 0 5 ALBUQUERQUE HEIGHTS............. 18 39 21 43 / 10 0 0 0 ALBUQUERQUE VALLEY.............. 14 40 16 46 / 10 0 0 0 ALBUQUERQUE FOOTHILLS........... 16 37 18 40 / 10 0 0 0 ALBUQUERQUE WEST MESA........... 17 38 20 43 / 10 0 0 0 SOCORRO......................... 26 50 28 55 / 10 0 0 0 SANDIA PARK/CEDAR CREST......... 11 34 21 40 / 50 0 0 5 MORIARTY/ESTANCIA............... 15 36 18 43 / 60 0 0 0 CARRIZOZO....................... 24 43 23 52 / 40 5 0 0 RUIDOSO......................... 18 36 20 45 / 60 20 0 0 RATON........................... 6 33 11 49 / 40 5 0 0 LAS VEGAS....................... 7 35 16 46 / 60 0 0 5 ROY............................. 8 33 22 50 / 40 10 0 5 CLAYTON......................... 5 27 20 51 / 40 20 0 0 SANTA ROSA...................... 14 38 23 52 / 60 20 0 5 TUCUMCARI....................... 12 35 22 52 / 50 20 0 0 FORT SUMNER..................... 18 37 19 54 / 60 20 0 5 CLOVIS.......................... 16 37 23 53 / 60 20 0 0 PORTALES........................ 17 38 22 54 / 60 20 0 0 ROSWELL......................... 22 42 27 58 / 70 20 0 0 && .ABQ WATCHES/WARNINGS/ADVISORIES... WINTER STORM WARNING UNTIL 6 PM MST THIS AFTERNOON FOR THE FOLLOWING ZONES...NMZ002-003. WINTER STORM WARNING UNTIL 4 AM MST THURSDAY FOR THE FOLLOWING ZONES...NMZ004-005-010>013-016-017-026. WINTER WEATHER ADVISORY UNTIL 4 AM MST THURSDAY FOR THE FOLLOWING ZONES...NMZ018>021. WINTER WEATHER ADVISORY UNTIL 6 PM MST THIS AFTERNOON FOR THE FOLLOWING ZONES...NMZ014-015. && $$ GUYER
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
1226 PM EST WED FEB 14 2007 .AVIATION /18Z-18Z/... CLASSIC NOREASTER CONTS TO WIND UP OFF THE NJ CST. XPCT CONT PDS OF HEAVY SNOW WITH LIFR CONDS ALL STATIONS THRU ABOUT 00Z. THIS WILL BE FLWD BY PDS OF LGTR SNOW THROUGH ABT 06Z WITH SOMEWHAT HIER CIGS AND VSBYS. MOST STATIONS WILL GO VFR BY 06Z AS THE LOW CONTS TO PULL NE. LES WILL BRING SCT SNOW SHWRS BACK INTO THE REGION...ESP NEAR THE END OF THE PD AS THE FLOW ALIGNS. && .PREV DISCUSSION... /ISSUED 1144 AM EST WED FEB 14 2007/ SHORT TERM /REST OF TODAY/... CURRENT FORECAST IN GOOD SHAPE JUST SOME MINOR ADJUSTMENTS TO AFTERNOON ACCUM AND STORM TOTALS. SFC LOW PRES CURRENTLY DEEPENING RAPIDLY OVER THE SOUTHERN NEW JERSEY COAST. MIXED PRECIP ACROSS SE FA WILL TRANSITION TO ALL SNOW SHORTLY AS COASTAL DEEPENS AND LOW/MID LEVEL FLOW BECOMES N/NE. BEST BANDING SIGNATURES EXPECTED THIS AFTERNOON ACROSS WESTERN CATSKILLS SOUTH AND EAST THROUGH PARTS OF THE SUSQU REGION, NRN TIER OF PA AND INTO THE POCONOS. RRM PREV DISCUSSION... /ISSUED 400 AM EST WED FEB 14 2007/ SHORT TERM /TODAY THROUGH FRIDAY/... MAJOR WINTER STORM BEARING DOWN ON THE REGION THIS MORNING...AS SURFACE LOW WINDS UP ALONG THE VIRGINIA CAPES. MODEL GUIDANCE...OVERALL...IS IN EXCELLENT AGREEMENT ON STORM EVOLUTION...AS NEGATIVE-TILT TROUGH ULTIMATELY CLOSES OFF A MID-LEVEL CIRCULATION BY AFTERNOON OVER NJ OR SOUTHEAST PA. IN RESPONSE...SURFACE WAVE CONTINUES TO DEEPEN...AS IT HEADS UP THE COAST. REGIONAL RADAR LOOPS SHOW QUITE A BIT OF HEAVY PRECIPITATION UPSTREAM...AND WITH VERY STRONG FORCED ASCENT ANTICIPATED...DUE TO THE ABOVE REFERENCED SYSTEMS...WE DON`T HAVE A PROBLEM BUYING OFF ON MODEL PRECIPITATION ESTIMATES OF 1.5-2.5" LIQUID BY EVENING. ADDITIONALLY...THERE ARE EXCELLENT SIGNALS FOR MESOSCALE BANDING THIS AFTERNOON...PARTICULARLY FROM THE TWIN TIERS NORTHWARD. IN-HOUSE RESEARCH SUGGESTS THESE PARTICULAR PARAMETERS MATCH QUITE WELL WITH PAST SIGNIFICANT SNOW EVENTS ACROSS NY AND PA. THE ONE FLY IN THE OINTMENT THIS MORNING IS THE MIXED PRECIPITATION...THAT HAS MADE IT UP INTO NY`S SOUTHERN TIER. THE RUC CAUGHT ONTO THIS POTENTIAL THE BEST...WITH AIRCRAFT SOUNDINGS DURING THE NIGHT AND SOME OF THE SOUNDINGS FROM LAST EVENING SHOWING THE ELEVATED WARY LAYER QUITE WELL. BUT EVEN THE RUC SUGGESTS ANY SLEET WILL BE FAIRLY SHORT LIVED OVER THE TWIN TIERS...AS COLDER AIR AND VERY STRONG UPWARD MOTION TAKE HOLD LATER THIS MORNING. SLEET AND FREEZING RAIN SHOULD HOLD ON A BIT LONGER OVER THE WYOMING VALLEY AND THE POCONOS...BUT WE ANTICIPATE A CHANGE BACK TO ALL SNOW FOR THESE AREAS...AS WELL...BY AFTERNOON. ALL IN ALL...PREVIOUSLY ADVERTISED STORM TOTALS STILL LOOK PRETTY GOOD...AND OTHER THAN SOME RELATIVELY MINOR TWEAKS...WE`RE CONTINUING TO RUN WITH THEM. FINAL AMOUNTS MAY YET ECLIPSE 2` FOR MANY AREAS OF CENTRAL NY AND PA`S NORTHERN TIER...WITH SLIGHTLY "LOWER" TOTALS OF ABOUT 15" FOR THE WYOMING VALLEY AND THE POCONOS. WINDS SHOULD BECOME STRONG AND GUSTY LATER THIS AFTERNOON AND TONIGHT...AS THE PRESSURE GRADIENT TIGHTENS. THIS WILL CREATE MUCH BLOWING AND DRIFTING SNOW...ALONG WITH BITTER COLD WIND CHILLS BY TONIGHT. ALTHOUGH A FEW GUSTS APPROACHING 35 MPH ARE POSSIBLE LATER TODAY AND THIS EVENING...WE THINK THAT BLIZZARD CRITERIA WILL GENERALLY NOT BE MET. THUS...WE THOUGHT IT BEST TO KEEP THINGS SIMPLE AND MAINTAIN THE CURRENT WARNING TYPES AS THEY ARE. IN THIS SAME VEIN...ALTHOUGH WIND CHILL ADVISORY CRITERIA IS EXPECTED TO BE MET TONIGHT AND THURSDAY...WE`LL LET THE MAIN STORM GET OUT OF THE WAY FIRST...BEFORE WE ADD SUCH HEADLINES. BESIDES THE BITTER COLD...THE OTHER CONCERN LATER THIS WEEK WILL BE THE RETURN OF LAKE EFFECT SNOW. AT THIS EARLY JUNCTURE...IT APPEARS THAT THE SOUTHERN TUG HILL REGION COULD BE IN FOR ANOTHER SIGNIFICANT LAKE SNOW EVENT BY LATER THURSDAY...LASTING INTO FRIDAY. ONCE AGAIN...HOWEVER...WE`LL LET THE PRESENT STORM CLEAR THE AREA BEFORE CONSIDERING ANY LAKE EFFECT SNOW WATCHES. -MJ && .BGM WATCHES/WARNINGS/ADVISORIES... NY...HEAVY SNOW WARNING UNTIL 10 PM EST THIS EVENING FOR NYZ009- 015>018-022>025-036-037-044>046-055>057. WINTER STORM WARNING UNTIL 10 PM EST THIS EVENING FOR NYZ062. PA...HEAVY SNOW WARNING UNTIL 10 PM EST THIS EVENING FOR PAZ038-039. WINTER STORM WARNING UNTIL 10 PM EST THIS EVENING FOR PAZ040- 043-044-047-048-072. && $$ AVIATION...DGM
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
1144 AM EST WED FEB 14 2007 .SHORT TERM /REST OF TODAY/... CURRENT FORECAST IN GOOD SHAPE JUST SOME MINOR ADJUSTMENTS TO AFTERNOON ACCUM AND STORM TOTALS. SFC LOW PRES CURRENTLY DEEPENING RAPIDLY OVER THE SOUTHERN NEW JERSEY COAST. MIXED PRECIP ACROSS SE FA WILL TRANSITION TO ALL SNOW SHORTLY AS COASTAL DEEPENS AND LOW/MID LEVEL FLOW BECOMES N/NE. BEST BANDING SIGNATURES EXPECTED THIS AFTERNOON ACROSS WESTERN CATSKILLS SOUTH AND EAST THROUGH PARTS OF THE SUSQU REGION, NRN TIER OF PA AND INTO THE POCONOS. RRM && .PREV DISCUSSION... /ISSUED 400 AM EST WED FEB 14 2007/ SHORT TERM /TODAY THROUGH FRIDAY/... MAJOR WINTER STORM BEARING DOWN ON THE REGION THIS MORNING...AS SURFACE LOW WINDS UP ALONG THE VIRGINIA CAPES. MODEL GUIDANCE...OVERALL...IS IN EXCELLENT AGREEMENT ON STORM EVOLUTION...AS NEGATIVE-TILT TROUGH ULTIMATELY CLOSES OFF A MID-LEVEL CIRCULATION BY AFTERNOON OVER NJ OR SOUTHEAST PA. IN RESPONSE...SURFACE WAVE CONTINUES TO DEEPEN...AS IT HEADS UP THE COAST. REGIONAL RADAR LOOPS SHOW QUITE A BIT OF HEAVY PRECIPITATION UPSTREAM...AND WITH VERY STRONG FORCED ASCENT ANTICIPATED...DUE TO THE ABOVE REFERENCED SYSTEMS...WE DON`T HAVE A PROBLEM BUYING OFF ON MODEL PRECIPITATION ESTIMATES OF 1.5-2.5" LIQUID BY EVENING. ADDITIONALLY...THERE ARE EXCELLENT SIGNALS FOR MESOSCALE BANDING THIS AFTERNOON...PARTICULARLY FROM THE TWIN TIERS NORTHWARD. IN-HOUSE RESEARCH SUGGESTS THESE PARTICULAR PARAMETERS MATCH QUITE WELL WITH PAST SIGNIFICANT SNOW EVENTS ACROSS NY AND PA. THE ONE FLY IN THE OINTMENT THIS MORNING IS THE MIXED PRECIPITATION...THAT HAS MADE IT UP INTO NY`S SOUTHERN TIER. THE RUC CAUGHT ONTO THIS POTENTIAL THE BEST...WITH AIRCRAFT SOUNDINGS DURING THE NIGHT AND SOME OF THE SOUNDINGS FROM LAST EVENING SHOWING THE ELEVATED WARY LAYER QUITE WELL. BUT EVEN THE RUC SUGGESTS ANY SLEET WILL BE FAIRLY SHORT LIVED OVER THE TWIN TIERS...AS COLDER AIR AND VERY STRONG UPWARD MOTION TAKE HOLD LATER THIS MORNING. SLEET AND FREEZING RAIN SHOULD HOLD ON A BIT LONGER OVER THE WYOMING VALLEY AND THE POCONOS...BUT WE ANTICIPATE A CHANGE BACK TO ALL SNOW FOR THESE AREAS...AS WELL...BY AFTERNOON. ALL IN ALL...PREVIOUSLY ADVERTISED STORM TOTALS STILL LOOK PRETTY GOOD...AND OTHER THAN SOME RELATIVELY MINOR TWEAKS...WE`RE CONTINUING TO RUN WITH THEM. FINAL AMOUNTS MAY YET ECLIPSE 2` FOR MANY AREAS OF CENTRAL NY AND PA`S NORTHERN TIER...WITH SLIGHTLY "LOWER" TOTALS OF ABOUT 15" FOR THE WYOMING VALLEY AND THE POCONOS. WINDS SHOULD BECOME STRONG AND GUSTY LATER THIS AFTERNOON AND TONIGHT...AS THE PRESSURE GRADIENT TIGHTENS. THIS WILL CREATE MUCH BLOWING AND DRIFTING SNOW...ALONG WITH BITTER COLD WIND CHILLS BY TONIGHT. ALTHOUGH A FEW GUSTS APPROACHING 35 MPH ARE POSSIBLE LATER TODAY AND THIS EVENING...WE THINK THAT BLIZZARD CRITERIA WILL GENERALLY NOT BE MET. THUS...WE THOUGHT IT BEST TO KEEP THINGS SIMPLE AND MAINTAIN THE CURRENT WARNING TYPES AS THEY ARE. IN THIS SAME VEIN...ALTHOUGH WIND CHILL ADVISORY CRITERIA IS EXPECTED TO BE MET TONIGHT AND THURSDAY...WE`LL LET THE MAIN STORM GET OUT OF THE WAY FIRST...BEFORE WE ADD SUCH HEADLINES. BESIDES THE BITTER COLD...THE OTHER CONCERN LATER THIS WEEK WILL BE THE RETURN OF LAKE EFFECT SNOW. AT THIS EARLY JUNCTURE...IT APPEARS THAT THE SOUTHERN TUG HILL REGION COULD BE IN FOR ANOTHER SIGNIFICANT LAKE SNOW EVENT BY LATER THURSDAY...LASTING INTO FRIDAY. ONCE AGAIN...HOWEVER...WE`LL LET THE PRESENT STORM CLEAR THE AREA BEFORE CONSIDERING ANY LAKE EFFECT SNOW WATCHES. -MJ PREV DISCUSSION... /ISSUED 1235 AM EST WED FEB 14 2007/ AVIATION /06Z-06Z/... WIDESPREAD IFR/LIFR CONDITIONS EXPECTED THROUGH THE MORNING HOURS AS SNOW CONTINUES TO OVERSPREAD THE REGION. WINDS WILL GENERALLY BE NORTHEASTERLY AT 7-10 KTS, AND WILL INCREASE OUT OF THE WEST- NORTHWEST TOMORROW TO AROUND 15 KTS. SOME MIXED PRECIPITATION HAS WORKED ITS WAY INTO AVP THE LAST HOUR, AND THIS COULD SPREAD CLOSE TO BGM OVER NEXT 4 HOURS. -DJP PREV DISCUSSION... /ISSUED 924 PM EST TUE FEB 13 2007/ SHORT TERM /REST OF TONIGHT/... WINTER STORM MOVED IN A FEW HOURS LATER THAN ANTICIPATED...BUT HAS ARRIVED NONETHELESS. LARGE AREA OF LIGHT-MODERATE SNOW ACROSS NRN PA AND OHIO AND HEADED FOR NY. DOMINANT SFC LOW PAST 12 HOURS HEADING INTO THE OH VALLEY...BUT LOW OVER SC IS BEGINNING TO GET THE UPPER HAND. THIS LOW WILL BE THE ONE TO WATCH THE NEXT 10-12 HRS AS IT MOVES OFF THE EAST COAST AND BEGINS TO RAPIDLY DEEPEN BY MORNING. EVENTUAL TRACK OF THIS SYSTEM WILL DETERMINE MOST LIKELY AREA TO BE IMPACTED BY BANDING AND HEAVIEST SNOW. STILL LOOKS LIKE SWATH WILL SET UP OVER CENTRAL CWA TOMORROW AFTERNOON FOR THE HIGHEST TOTALS. FOR THE IMMEDIATE SHORT TERM...NOT A LOT OF CHANGE EXPECTED. AREA OF SNOW HAS OVERSPREAD MOST OF THE AREA WITH MODERATE TO HEAVY SNOW MOVING INTO NEPA AT THIS TIME. THUS FAR...HAVE SEEN 1-2 INCHES OVER NEPA AND ARND ONE INCH OVER SRN TIER. GENERALLY 0.5-1.00 INCH PER HOUR SINCE SNOW HAS STARTED. SLEET/FZRA LINE ALONG AND SOUTH OF I-70 AT PRESENT. BASED ON LATEST 00Z MODELS...THIS LINE SHOULD MOVE INTO CNTRL/ERN PA THRU THE OVERNIGHT AND UP INTO NEPA CTYS BY DAYBREAK. LATEST RUNS SUGGEST SLEET MAY MIX IN FOR A BRIEF PERIOD OF TIME EARLY MORNING FROM BROOME/SUSQUEHANNA CTY EAST. THIS WILL LIKELY LAST APPROX 3 HRS BEFORE COLD AIR RETURNS. SOME BANDING STILL LOOKS LIKELY ACROSS SRN TIER/SUSQUEHANNA AREA AND EAST DURING THE AFTERNOON HOURS. THIS MAY BE THE HEAVIEST PORTION OF THE STORM FOR THE REGION WITH THE GREATEST ACCUMS COMING RIGHT ARND THE AFTERNOON COMMUTE. ALL IN ALL...CURRENT FCST LOOKS IN GOOD SHAPE AND DO NOT PLAN ON MANY CHANGES AT THIS TIME. HAVE RE-ISSUED HEADLINES AND DROPPED AMOUNTS SLIGHTLY OVERNIGHT OVER CNY TO THE 8-12 INCH RANGE. OTHER THAN THAT...WILL LEAVE THINGS ON TRACK FOR THE TIME BEING. DEPENDING ON THE SPEED OF THE SYSTEM ONCE IT INTENSIFIES OFF THE COAST...MAY NEED TO EXTEND WARNING INTO EVENING HOURS. AVIATION /00Z-00Z/... SNOW HAS DEVELOPED THIS EVENING ACROSS ALL TAF SITES AS MAJOR WINTER STORM IMPACTS THE AREA DURING THIS TAF PERIOD. CONDITIONS HAVE DETERIORATED QUICKLY THIS EVENING WITH THE START OF SNOW. WIDESPREAD IFR TO LIFR EXPECTED THROUGH MUCH OF THE NIGHT. IT LOOKS LIKE THE HEAVIEST SNOW MAY FALL LATE MORNING WEDNESDAY THROUGH WEDNESDAY AFTERNOON WHEN A FEW HOURS OF VLIFR ARE LIKELY. WINDS WILL INCREASE OUT OF THE NORTHEAST DURING THE DAY WEDNESDAY WITH SUSTAINED 15-25KTS DURING THE AFTERNOON AND GUSTS TO 35 MPH POSSIBLE. PREV DISCUSSION... /ISSUED 405 PM EST TUE FEB 13 2007/ SHORT TERM /REST OF TONIGHT THROUGH THURSDAY/... HUGE STORM HEADING OUR WAY FOR TONIGHT INTO WED NGT. SNOW IN PA HAS MADE LITTLE PROGRESS AGAINST THE DRY LOW LEVEL AIR. DEWPOINTS BELOW ZERO EVEN INTO PA. SNOW NOW TO ELZ SO WILL START MOVG INTO TWIN TIERS AND NE PA NEXT 3 HOURS THEN GET INTO NE CWA TOWARDS MIDNIGHT. DYNAMICS ARE ABOUT AS GOOD AS CAN BE EXPECTED WITH LOTS OF LIFT AND MOISTURE. COUPLED NRN JET OVER SE CANADA AND SOUTHERN JET IN SE US WILL PROVIDE MUCH UL DIVERGENCE. SFC LOW IN KY WILL TRANSFER TO THE COAST AND SLOW. A SECOND AREA OF PRESSURE FALLS ALONG COAST STARTING TO FORM. THE UL TROF AND LOW IN THE WRN GREAT LAKES BECOMES NEGATIVE TILTED AS IT DIGS SE TOWARDS BGM. LOW LEVEL JET INCREASES TO 60 KTS AS THE LOW BOMBS ON THE COAST BRINGING IN ATLANTIC MOISTURE. FOR NOW GULF OPEN AT MID LEVELS BRINGING IN MORE MODELS. EACH MODEL RUN HAS PUT MORE QPF IN THE CWA AND NOW HAS A GOOD 2 INCHES. AT A CONSERVATIVE 10 TO 1 SNOW RATIO THIS IS 20 INCHES. ACROSS THE NORTH WITH THE COLD AIR AT LOW LEVELS AND LESS WARM AIR ALOFT AMOUNTS COULD GET CLOSE TO 3 FEET. ALSO ACROSS NY BANDING SIGNATURES AS THE COASTAL LOW MOVES INTO SE NEW ENGLAND. IN THE FAR SE SOUNDINGS SHOW A WARM LAYER WHICH WILL CAUSE SLEET THERE LATE TONIGHT INTO WED AFTN. THIS WILL CUT DOWN ON THE SNOW TOTALS SO...ONLY 10 TO 20 INCHES. THE STORM SLOWLY PULLS OUT LATE WED AFTN AND WED EVE. COULD BE SEVERAL MORE INCHES IN THE NE. ALSO WED AFTN AND NGT THE WINDS WILL SHIFT AROUND TO N THEN W AND INCREASE TO 15 TO 25 MPH. SNOW WILL BE DRIFTING WHILE WIND CHILLS DROP BELOW ZERO. WITH THE LOW LEVEL FLOW SHIFTING AROUND OUR EXTREME N COULD STAY IN LAKE ENHANCED SNOW INTO THU WHEN THE STORM WILL FINALLY BE FAR ENOUGH AWAY. ON THU THE LAKE EFFECT GETS GOING AGAIN AS 850 TEMPS FALL BELOW -20C. THE UPPER LEVEL LOW MOVG ACROSS SRN ONTARIO WILL BRING THE DYNAMICS FOR ANOTHER CHC OF HEAVY LES. FOR NOW NOT HITTING IT HARD. WILL ALSO WAIT ON LES WATCH UNTIL SYNOPTIC STORM CLEARS THE AREA. NRN ONEIDA COUNTY AGAIN IN THE BEST AREA FOR A SINGLE BAND. LONG TERM.../THURSDAY NIGHT THROUGH TUESDAY/... BEHIND COASTAL UPPER LEVEL TROF WILL PERSIST ACROSS THE NORTHEAST UNTIL THE END OF EXTENDED PERIOD. OCCASIONAL H5 SHORT WAVES WILL REINFORCE THE UPPER LEVEL TROF AND COLD AIR THROUGH MONDAY BEFORE SOME MODERATION AND RISING HEIGHTS BEGINS ON TUESDAY. THURSDAY NIGHT THROUGH FRIDAY NIGHT, LAKE EFFECT SNOW WILL IMPACT NRN CWA WITH WESTERLY FLOW AND ABUNDANT LOW LEVEL MOISTURE. FRIDAY NIGHT, ACTIVITY WILL WEAKEN AS T85 WARMS AND FLOW BACKS IN ADVANCE OF SFC LOW MOVING INTO OHIO VALLEY. SATURDAY NIGHT/SUNDAY, INCLUDED CHC POPS ENTIRE FA AS WEAK SFC LOW MOVES ACROSS SRN CANADA AND ANOTHER MOVES OFF THE MID ATLANTIC COAST. REST OF EXTENDED LOOKS FAIRLY QUIET UNTIL TUESDAY WHEN NEXT SYSTEM APPROACHES AREA FROM THE OHIO VALLEY. -RRM && .BGM WATCHES/WARNINGS/ADVISORIES... NY...HEAVY SNOW WARNING UNTIL 10 PM EST THIS EVENING FOR NYZ009- 015>018-022>025-036-037-044>046-055>057. WINTER STORM WARNING UNTIL 10 PM EST THIS EVENING FOR NYZ062. PA...HEAVY SNOW WARNING UNTIL 10 PM EST THIS EVENING FOR PAZ038-039. WINTER STORM WARNING UNTIL 10 PM EST THIS EVENING FOR PAZ040- 043-044-047-048-072. && $$

AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
1240 AM EST FRI FEB 16 2007 .AVIATION... MVFR CIGS BEING REPORTED AT BOTH SITE AT THIS TIME. NAM-WRF SHOWS LOTS OF 925 MB MSTR AROUND WITH THIS SLOWLY SHIFTING EAST OVERNIGHT AND SKIES CLEARING BY 12Z. COULD SEE THINGS POTENTIALLY CLEAR EARLIER BUT FOR NOW WILL JUST GO WITH 12Z TIMING. AFTER THAT MAINLY HIGH CLOUDS TO DEAL WITH UNTIL TOWARDS 00Z WHEN EFFECTS OF CLIPPER BEGIN TO ARRIVE. WILL BEGIN TO FINE TUNE A BIT WITH 12Z PACKAGE TO GIVE SOME TIMING AND DETAIL FOR THAT TIME FRAME. && .SHORT TERM... TONIGHT AND FRIDAY...HAVE ISSUED A WIND CHILL ADVISORY FOR MUCH OF NORTHERN INDIANA AND NORTHWEST OHIO...EXCEPT FOR AREAS NEAR THE MICHIGAN STATE LINE. THE CORE OF ARCTIC AIR IS EXPECTED TO MOVE ACROSS THE AREA TONIGHT AS SKIES BECOME CLEAR/MOSTLY CLEAR EXCEPT FOR FAR SOUTHERN LOWER MICHIGAN AND BORDERING AREAS TO THE SOUTH. PER ACARS/TAMDAR OBS...NAM/WRF HAS INITIALIZED THE UPSTREAM CORE WELL WITH 925 MB TEMPS BETWEEN -18C AND -19C...WHICH WAS EVEN COLDER THAN THE AIRMASS OVER THE AREA THIS MORNING WHEN FWA...DFI AND GUS DROPPED TO BETWEEN -8F AND -12F. SNOW DEPTHS STILL 8 INCHES TO CLOSE TO 2 FEET OVER THE SOUTHERN HALF OF THE AREA...SOUTH OF HIGHWAY 6...AND SUFFICIENT FOR EVEN RECORD COLD LOWS IF CONDITIONS ARE RIGHT. WINDS SHOULD STAY UP ENOUGH TO CAUSE WIND CHILL TEMPERATURES TO FALL TO BETWEEN -20F AND -25F TONIGHT INTO FRIDAY MORNING. NCEP GFS/MAV AND NGM/FWC MOS NOT HANDLING LOWS VERY WELL...POSTING A LARGE WARM BIAS OF AS MUCH AS 17F. NEEDLESS TO SAY...CUT MOS TEMPS SIGNIFICANTLY. CONDITIONS WILL STILL BE CHILLY FRIDAY MORNING AS RETURN FLOW INCREASES...BUT WARM AIR ADVECTION JUST BEGINNING. && .LONG TERM... FRIDAY NIGHT THROUGH THURSDAY. UPR LVL WEATHER PATTERN OVER THE UNITED STATES AND CANADA WILL UNDERGO A PATTERN SHIFT DURING THE EXTENDED PERIOD. COLD POLAR VORTEX LOCATED OVER SE CANADA AND PREDOMINATE NORTHWEST FLOW WILL GRADUALLY WEAKEN AND SHIFT NORTHWARD BY EARLY NEXT WEEK. IN THE MEANTIME...THERE WILL BE A CLIPPER SYSTEM TO CONTEND WITH IN THE IMMEDIATE LONG TERM PERIOD...AS WELL AS ANOTHER ROUND OF LAKE EFFECT SNOW IN ITS WAKE. PREFER THE 12Z GFS VERSUS THE NAM-WRF IN REGARDS TO THE UPCOMING CLIPPER SYSTEM AND WILL THUS USE CLOSELY. MID LVL S/WV WAS PUSHING ONSHORE ACRS BRITISH COLUMBIA THIS AFTN. THIS FEATURE WILL DIVE RAPIDLY SE INTO THE NRN PLAINS ON FRIDAY...THEN IT WILL HEAD TOWARD THE WRN GREAT LAKES/LOWER OHIO VALLEY FRIDAY NIGHT. DECENT ISENTROPIC LIFT/WAA AHEAD OF THE CLIPPER WILL BRING A SWATH OF SNOW TO THE REGION...BEGINNING FRIDAY EVENING AND CONTINUING INTO SATURDAY MORNING. THERE WILL ALSO BE SOME DYNAMICAL LIFT WITH THE UPR LVL S/WV...AIDING IN UPWARD VERTICAL MOTION. THE MODIFIED GARCIA METHOD AND MODEL QPF INDICATE THAT 2 TO 4 INCHES OF SNOW WILL FALL ACROSS THE REGION FROM FRIDAY NIGHT INTO SATURDAY MORNING. AS THE CLIPPER PASSES TO THE SE BY SATURDAY AFTERNOON...SNOW WILL TAPER OFF. TEMPERATURES FRIDAY NIGHT WILL BE NON DIURNAL AS WAA AND WINDS FROM THE SOUTH/SOUTHWEST ALLOW TEMPS TO RISE SLOWLY TOWARD SATURDAY MORNING. THUS...WILL GO WITH AN EARLY EVENING LOW IN THE MID TEENS WITH TEMPS WARMING TO THE UPPER TEENS TO LOWER 20S BY SATURDAY MORNING. HIGHS ON SATURDAY WILL WARM INTO THE UPPER 20S. FOR SATURDAY NIGHT INTO SUNDAY NIGHT...ONE MORE S/WV WILL DIVE SE OUT OF CENTRAL CANADA INTO THE GREAT LAKES REGION. THIS FEATURE WILL BRING A BRIEF REINFORCING SHOT OF ARCTIC AIR. THE COLD AIR MOVING ACRS THE RELATIVELY WARMER WATERS OF LAKE MICHIGAN WILL GENERATE LAKE EFFECT SNOW SHOWERS. CURRENT FORECAST FETCH OF 300 TO 320 IS EXPECTED. HAVE MAINTAINED CURRENT HIGH CHC POPS IN THE FAVORED LAKE EFFECT COUNTIES FOR SATURDAY NIGHT...AND HAVE EXTENDED THE HIGH CHC INTO SUNDAY. LAKE EFFECT SNOW SHOWERS WILL DIMINISH QUICKLY SUNDAY NIGHT AS A RIDGE OF HIGH PRESSURE BUILDS TOWARD THE REGION. TEMPERATURES WILL REMAIN MUCH BELOW NORMAL DURING THIS PERIOD. AS STATED BEFORE...A PATTERN SHIFT IS IN THE OFFING FOR NEXT WEEK. S/WV ACTIVITY WILL COME ONSHORE ACRS THE WEST COAST...AND WILL TAKE A SRN TRAJECTORY ACRS THE SRN UNITED STATES. MEANWHILE...SOME S/WV ENERGY IN THE NRN JET STREAM (A SPLIT FLOW PATTERN) WILL PUSH A COLD FRONT THROUGH THE REGION TUESDAY/TUESDAY NIGHT. MODELS HAVE BEEN INCONSISTENT WITH THE SRN STREAM S/WV ENERGY...OSCILLATING ITS POSITION FROM RUN TO RUN. THE PATTERN THIS WINTER HAS BEEN TO TAKE THESE SRN STREAM S/WVS END FARTHER NORTH THAN FORECAST. MUCH UNCERTAINTY AT THIS POINT...SO WILL WAIT TO SEE HOW THIS ONE PANS OUT. IN THE MEANTIME...WILL JUST FOCUS ON THE NRN STREAM S/WV AND ASSOCD COLD FRONT TUESDAY/TUESDAY NIGHT. PCPN TYPE WILL BE A CONCERN AS TEMPS WILL WARM TO SLIGHTLY ABOVE FREEZING. WILL GO WITH A CHC OF RAIN OR SNOW ON TUESDAY...WITH A CHC OF SNOW TUESDAY NIGHT IN THE WAKE OF THE FRONT. HIGH PRESSURE IS FCST SETTLE ACRS THE FCST REGION WEDNESDAY AND THURSDAY. WILL FCST PARTLY CLOUDY SKIES WITH TEMPS AT OR SLIGHTLY ABOVE NORMAL. && .IWX WATCHES/WARNINGS/ADVISORIES... IN...WIND CHILL ADVISORY FROM 10 PM EST /9 PM CST/ THIS EVENING TO 11 AM EST /10 AM CST/ FRIDAY FOR INZ008-009-012>018-020- 022>027-032>034. MI...NONE. OH...WIND CHILL ADVISORY FROM 10 PM THIS EVENING TO 11 AM EST FRIDAY FOR OHZ004-005-015-016-024-025. LM...SMALL CRAFT ADVISORY UNTIL 7 PM EST FRIDAY FOR LMZ043-046. && $$ AVIATION...FISHER SHORT TERM...SKIPPER LONG TERM....HICKMAN
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
MID AM EST FRI FEB 16 2007 .AVIATION...(06Z TAFS)... VFR THRU THE PD. LIGHT NLY FLO WILL GIVE WAY TO INCREASING SW FLO FRI AS A RIDGE OF HI PRES MOVES ACRS OUR FA TNGT AND EARLY FRI. BY LATE IN THE PD...RIDGE WILL BE POSITIONED ACRS FAR EKY RESULTING IN A SW RETURN FLO. MID/UPR LVL LOW DROPPING SEWD THRU NERN AR ATTM...WILL PUSH SOME MID/HI LVL CIGS ACRS THE BWG VCNTY PERIODICALLY OVERNIGHT. SCT LO STRATUS ARND 010 WILL AFFECT THE LEX VCNTY TIL 08Z. .UPDATE... MID/UPR LEVEL CIRCULATION SEEN ON WATER VAPOR IMAGERY TRACKING SEWD INTO NRN AR ATTM...PUSHING SCT MID/HI LEVEL CLDS PRIMARILY OVER DOWNSTATE KY. ACRS THE NRN HALF OF OUR FA...EXPECT JUST SOME CI OVRNGT...SO MOCLR N TO PCLDY SKIES S WILL PREVAIL. NAM HAS BACKED OFF LO STRATUS DEVELOPMENT IT WAS SHOWING WITH THE 18Z RUN...AS INDICATED BY ITS FCST 00Z SOUNDINGS. DID NOT CHG TEMPS MUCH OVERNIGHT...WILL LEAVE WIND CHILLS HIGHLIGHTED IN THE HWO WITH THE COMBO OF TEMPS/WINDS NOT QUITE AS COLD PER WIND CHILLS AS PRVS FCST...AROUND -5 FAR N AND +5 FAR S...BOTTOMING OUT ARND 10Z. DK .SHORT TERM (TONIGHT-FRIDAY)... MAIN FOCUS IN THE SHORT TERM WILL BE OVER THE NEXT 6-9 HOURS. RADAR SHOWING SOMEWHAT WIDESPREAD FLURRY OR -SHSN ACTIVITY DEVELOPING FROM ROUGHLY HOP-SDF-CVG AS OF 18Z. LAPSE RATES ARE VERY STEEP ON LATEST ACARS SOUNDINGS AT SDF (THROUGH THE -15C LEVEL)...BUT LOW LEVELS ARE QUITE DRY. BEST CHANCES FOR -SHSN WILL BE ALONG RELATIVE MAX IN SFC DEWPOINTS...WHICH CURRENTLY STRETCHES FROM WRN KY UP INTO THE SDF-CVG CORRIDOR. GFS LOW LEVEL RH FIELDS PICK UP ON THIS ENHANCED CLOUDINESS AT THE 900/925MB LEVELS...AND TRANSLATE FEATURE SE INTO OUR ERN COUNTIES BY 22-00Z THIS EVENING...AND OUT OF THE CWA SHORTLY THEREAFTER. WILL INCLUDE A "LATE AFTERNOON" PERIOD IN THE ZONES FOR ISLTD -SHSN. NOT EXPECTING ANY ACCUMS OTHER THAN TRACE GIVEN THE RELATIVELY DRY LOW LEVELS. CLOUD COVER TONIGHT WILL PRESENT A CHALLENGE...WITH NAM DEVELOPING WIDESPREAD LOW STRATUS WHILE GFS IS SIGNIFICANTLY DRIER IN THE LOW LEVELS. FEEL THAT NAM IS OVERDEVELOPING LOW STRATUS THIS AFTN OVER THE SNOW FIELDS NORTH OF THE CWA...WHICH IS SEEN IN THE 6-9HR VERIFICATIONS OF THE 12Z RUN...SO WILL SIDE WITH GFS. WILL STILL MAINTAIN AT LEAST 30% CLOUD COVER OVERNIGHT WITH BANDS OF MID/HIGH LEVEL CLOUDS PASSING THROUGH. LOWS TONIGHT WILL BE VERY COLD OVER THE N 1/3 OF THE DISTRICT...MID-UPPER SINGLE DIGITS. WIND CHILLS WILL LIKELY DROP INTO THE -5 TO -10F RANGE BY DAYBREAK...SO WILL HIGHLIGHT THIS IN HAZ WX OUTLOOK SINCE IT IS BORDERLINE ADVISORY CRITERIA. OVER SRN KY...WCI VALUES SHOULD BE WARMER (~ZERO TO 5 ABOVE). SIG WX NIL DURING THE DAYLIGHT HOURS FRIDAY WITH LOW LEVEL FLOW TURNING MORE SOUTHERLY TOWARD LATE AFTN AHEAD OF APPROACHING CLIPPER. SIGNIFICANT THERMAL TROF REMAINS OVER THE CWA...AND EVEN WITH EXPECTED SUNSHINE...TEMPS WILL ONLY BE A FEW DEGREES WARMER THAN TODAY. CS .LONG TERM (FRIDAY NIGHT-THURSDAY)... ...CLIPPER SYSTEM TO BRING A PERIOD OF SNOW TO THE REGION LATE FRIDAY AND SATURDAY... FRIDAY NIGHT THROUGH SUNDAY NIGHT... OVERALL...SHORT TERM MODEL SOLUTIONS ARE COMING INTO SOMEWHAT BETTER AGREEMENT WITH THIS WEEKENDS CLIPPER SYSTEM. 12Z NAM-WRF AND GFS CONTINUE TO SHOW UPPER LEVEL WAVE AND ASSOCIATED SFC LOW TRACKING SOUTHEAST TOWARD THE OHIO VALLEY. THOUGH AS THE SFC LOW GETS HERE...IT WILL BE WEAKENING. GFS AND NAM CONTINUE TO DIFFER ON THE FORECAST TRACK OF THE SYSTEM WITH THE NAM TAKING THE LOW NORTH OF THE RIVER WITH THE GFS A BIT FURTHER SOUTH. THE GFS TIMING IS FASTER THAN THE NAM WHICH WOULD KEEP MUCH OF THE HEAVIEST PRECIPITATION FALLING DURING THE DAY ON SATURDAY. THERMAL PROFILES HAVE TRENDED COLDER OVER THE LAST FEW RUNS AND OVERALL PROFILES SUGGEST SNOW AS THE PREDOMINANT PRECIPITATION. MAIN FORECAST CHALLENGE HERE WHAT WILL BE THE OVERALL TRACK OF THE SYSTEM. SO FAR THIS SEASON...THE NAM HAS OUTPERFORMED THE GFS SOLUTION HANDS DOWN. THE QPF VALUES HAVE BEEN MORE REALISTIC AS WELL AS THE THERMAL PROFILES. THE GFS HAS ALSO TENDED TO BE COLDER AND MORE WET IN TERMS OF QPF. AT THIS TIME...I THINK THE BEST APPROACH WOULD BE TO GO WITH A BLEND OF BOTH MODELS BUT CLOSER TO THE NAM SOLUTION. QPF AMOUNTS THROUGH THE ENTIRE EVENT WILL BE LESS THAN 0.25 INCHES AND WITH EXPECTED WARMTH IN THE PBL DURING THE DAY ON SATURDAY...SNOW RATIOS WILL BE CLOSE TO CLIMO WHICH IS 12:1. SNOW AMOUNTS FROM THE NAM WOULD SUGGEST 1-2 INCHES WHILE THE GFS SUGGESTS 2-4 INCHES. FOR NOW WILL PLAN ON A GENERAL 1-3...BUT MOST LOCATIONS WOULD LIKELY SEE 1-2 INCHES. IF THE SYSTEM TRENDS FURTHER NORTH...LESS SNOW IS LIKELY. TEMPERATURES SATURDAY WILL START OFF COLD WITH OVERNIGHT LOWS IN THE UPPER TEENS TO THE LOWER 20S. STUCK CLOSER THE THE 2M GFS NUMBERS FOR SATURDAY AFTERNOON WITH HIGHS IN THE UPPER 20S TO AROUND 32. AS CLIPPER SYSTEM MOVES EAST...DEEP NORTHWEST FLOW WILL CONTINUE ACROSS THE REGION. WEAK STATIC STABILITY AND LEFT OVER MOISTURE WILL LIKELY PRODUCE SCT SNOW SHOWERS DURING THE DAY ON SUNDAY ACROSS THE NORTHEAST THIRD OF THE FA. FOR THAT REASON HAVE OPTED TO KEEP LOW CHC POPS IN THE FORECAST HERE. TEMPERATURES WILL REMAIN WELL BELOW NORMAL WITH HIGHS IN THE LOW TO MID 20S IN THE NORTH TO THE UPPER 20S IN THE SOUTH. AS HIGH PRESSURE BUILDS IN...SKIES SHOULD CLEAR OUT SUNDAY NIGHT AND TEMPS WILL RAPIDLY COOL. TEMPS MONDAY MORNING WILL BE HIGHLY DEPENDENT ON SNOW COVER. SINCE WE FEEL WE`LL HAVE SOME SNOW ON THE GROUND...LOWS IN THE UPPER SINGLE DIGITS WILL BE POSSIBLE ACROSS THE NORTHEAST SECTIONS WITH MID TEENS ACROSS THE SOUTHWEST. MONDAY THROUGH THURSDAY... EXTENDED MODEL SOLUTIONS CONTINUE TO SHOW A GENERAL MODERATION IN TEMPERATURES OVER THE UPCOMING WEEK. SFC HIGH PRESSURE IS FORECAST TO MOVE EAST OF THE REGION BY LATE MONDAY ALLOWING DEEP SOUTHWESTERLY FLOW TO RETURN TO THE REGION. COMBINATION OF DEEP SW FLOW COMING OFF THE GULF SHOULD RESULT IN SOME SCT LIGHT PRECIPITATION BY TUESDAY. INITIAL PRECIP MAY BE MIXED OR SNOW...BUT WOULD QUICKLY CHANGE TO RAIN AS TEMPS WARM. 00Z GFS ENSEMBLE SOLUTIONS SUPPORT THIS AND CURRENT FCST HAS THIS COVERED WELL. LATEST 12Z GFS HAS TRENDED MORE SOUTHERLY WITH SFC CYCLONE GOING ACROSS THE GULF COAST STATES. THIS IS IN STARK CONTRAST TO THE 06Z GFS RUN. GIVEN THE RATHER POOR RUN TO RUN CONSISTENCY GENERALLY PLAN ON STICKING CLOSE TO THE 00Z GFS ENSEMBLE PACKAGE FOR THIS PERIOD. ENSEMBLE PACKAGE IS A BIT FURTHER NORTH WITH SFC LOW GOING ACROSS THE SOUTHERN STATES. NET RESULT IS A CHANCE OF PRECIPITATION ON WEDNESDAY WITH DRIER CONDITIONS RETURNING BY THU. THERMAL PROFILES SUGGEST PRECIP ON WED WILL BE RAIN AS OVERALL ARCTIC PATTERN LOOSES ITS GRIP ON THE EASTERN THIRD OF THE COUNTRY. -MJ .AVIATION...(00Z TAFS)... VFR THRU THE PD. LIGHT NLY FLO WILL GIVE WAY TO INCREASING SW FLO FRI AS A RIDGE OF HI PRES MOVES ACRS OUR FA TNGT AND EARLY FRI. BY LATE IN THE PD...RIDGE WILL BE POSITIONED ACRS FAR EKY RESULTING IN A SW RETURN FLO. CIGS ARND 040 IN THE LEX VCNTY WILL BECOME SCT BY 03Z. && .LMK WATCHES/WARNINGS/ADVISORIES... KY...NONE. IN...NONE. && $$
AREA FORECAST DISCUSSION
NWS BALTIMORE MD/WASHINGTON DC
310 AM EST FRI FEB 16 2007 .SHORT TERM /TODAY THROUGH TONIGHT/... WATER VAPOR LOOP SHOWS A DEEPENING UPPER LOW NEARING THE CANADIAN MARITIMES...AS A SHORT WAVE MOVES EAST INTO THE TENNESSEE VALLEY. ACARS 400-250MB WIND OBSERVATIONS SHOW A 190-210KT SOUTHWESTERLY JET FROM THE GULF STATES THROUGH THE CAROLINAS. 04Z SURFACE ANALYSIS PLACED A DECAYING COLD FRONT ACROSS THE GULF STATES. A 1033MB ANTICYCLONE DOMINATED THE CENTRAL CONUS. STRATO-CU GENERATED BY COLD ADVECTION ACROSS THE GREAT LAKES IS AFFECTING THE MOUNTAINS AND MARYLAND/WEST VIRGINIA PAN HANDLE REGION EARLY THIS MORNING. EXPECT DISSIPATING TREND THROUGH THE DAY AS ANTICYCLONIC FLOW BUILDS NORTHEAST ACROSS THE LOWER GREAT LAKES BEHIND THE SHORT WAVE. THE APPROACH OF THE SHORT WAVE WILL SERVE TO ALLOW MID AND UPPER LEVEL CLOUDS TO DEVELOP ALONG THE UPPER LEVEL JET AXIS EARLY THIS MORNING ACROSS THE SOUTHEAST ZONES...BEFORE THE JET AXIS PUSHES SOUTHEAST OF THE REGION. PRESSURE GRADIENT WILL SUPPORT SOME WIND GUSTS OF 20 MPH TODAY. WITH THE CORE OF THE COLD AIR ALOFT WILL BE PROGRESSING TO THE NORTHEAST...EXPECT HIGH TEMPERATURES ABOUT A CATEGORY WARMER THAN YESTERDAY. ANTICIPATE CLEAR TO MOSTLY CLEAR CONDITIONS TONIGHT IN BETWEEN TWO SYSTEMS. WINDS WILL DECOUPLE WITH THE SURFACE RIDGE AXIS ACROSS THE MID ATLANTIC. GIVEN A DRY ATMOSPHERE...CLEAR SKIES...AND SNOW/SLEET PACK...EXPECT TEMPERATURES TO FALL QUICKLY. THE EXCEPTION SHOULD BE IN THE HIGHER TERRAIN ABOVE 2500FT WHERE COUPLED FLOW CONTINUES TO CARRY WARMER AIR ALOFT INTO THE REGION. && .AVIATION... COLD ADVECTION STRATO-CU WILL AFFECT MAINLY KMRB AND POSSIBLY KIAD DURING THE MORNING...BEFORE DISSIPATING. GRADIENT WILL SUPPORT WIND GUSTS AROUND 20KTS AFTER DAYBREAK. && .MARINE... 00Z MET/MAV MOS AT THOMAS POINT INDICATE SUSTAINED WINDS JUST ABOVE 15 KNOTS TODAY...AND NEAR 10 KNOTS TONIGHT. PROXIMITY 00Z NAM/GFS BUFKIT FORECAST SOUNDINGS INDICATE 20-25KT WIND GUST POTENTIAL THROUGH THIS EVENING. ICE COVERAGE ACROSS THE EXTREME NORTHERN BAY IS CLOSE TO 7-9 TENTHS. SMALL CRAFT ADVISORIES WILL BE LIKELY SUNDAY INTO MONDAY WITH MORE COLD ADVECTION AND STRONG WINDS MOVING IN BEHIND A PAIR OF SHORT WAVES THIS WEEKEND. && .TIDES... CURRENT TIDAL DEPARTURES ARE A FOOT TO A FOOT AND A HALF BELOW ASTRONOMICAL PREDICTIONS...DUE TO A RECENT BLOWOUT. THE LUNAR CYCLE IS WANING TO A NEW MOON (3 PERCENT FULL). THE CHESAPEAKE BAY OPERATIONAL FORECAST SYSTEM AND THE NOAA EXTRATROPICAL STORM SURGE MODEL MAINTAIN CURRENT TIDAL DEPARTURES THROUGH THIS AFTERNOON. && .LONG TERM /SATURDAY THROUGH THURSDAY/... THIS WEEKEND A PAIR OF CLIPPER SHORT WAVES WILL MOVE THROUGH THE NW FLOW AROUND THE EASTERN UPPER TROUGH. THE FIRST WILL BEGIN MOVING IN SATURDAY MORNING ALTHOUGH THE BULK OF IT WILL AFFECT US SAT AFTERNOON INTO SAT NIGHT. THE WAVE ACTUALLY PASSES JUST S OF US SO THERE IS A CHC OF LIGHT PRECIP. ALSO THERE IS A FAIR AMOUNT OF MID LVL MOISTURE WITH IT FOR A CLIPPER. TEMPS ARE CERTAINLY COLD ENOUGH THAT THERE WILL BE NO QUESTION ANYTHING WILL BE SNOW. LOWEST LVLS OF THE ATMOS ARE DRY HOWEVER AND ANY SNOW WILL HAVE TO OVERCOME THAT...ESP OVER THE LOW LANDS. WILL HAVE CHC POPS FOR MOST EXCEPT LIKELY IN THE MOUNTAINS AND DEF SNOW ON THE UPSLOPE SIDE. LATE SUNDAY ANOTHER WEAKER CLIPPER COMES THROUGH...THE LAST ONE. THAT HAS A MORE COMPACT SHAPE TO THE VORTICITY...BUT MOISTURE APPEARS TO BE LACKING FOR NOW. AFTER THAT...A MODERATION TREND IS IN ORDER AS THE UPPER FLOW BECOMES MORE ZONAL THROUGH 240 HOURS. TOWARD MID WEEK A STATIONARY FRONT TAKES UP RESIDENCE OVER THE AREA WHICH WOULD BRING A CHC OF RAIN WITH IT STREAMING UP ALONG THE FRONT FROM SW TO NE AND OVER THE MID ATLANTIC. && .LWX WATCHES/WARNINGS/ADVISORIES... DC...NONE. MD...WIND CHILL ADVISORY UNTIL 9 AM EST THIS MORNING FOR MDZ003-501- 502. VA...WIND CHILL ADVISORY UNTIL 9 AM EST THIS MORNING FOR VAZ021-028. WV...WIND CHILL ADVISORY UNTIL 9 AM EST THIS MORNING FOR WVZ050>052- 054-055-501>504. MARINE...SMALL CRAFT ADVISORY UNTIL 10 PM EST THIS EVENING FOR ANZ530>537. && $$ SHORT TERM/AVIATION/TIDES...ROGOWSKI LONG TERM...STRONG MARINE...ROGOWSKI/STRONG

AREA FORECAST DISCUSSION
NWS BALTIMORE MD/WASHINGTON DC
1106 AM EST FRI FEB 16 2007 .SHORT TERM /REST OF TODAY/... SURFACE ANALYSIS FROM 15Z SHOWS HIGH PRESSURE CENTERED OVER SOUTH TEXAS AND EXTENDING NORTH EAST THROUGH THE MID ATLANTIC. WITH THE EXCEPTION OF THE FAR NORTHWESTERN ZONES...THE CWA IS SUNNY WITH TEMPERATURES WARMING INTO THE 20S. GUSTY WEST WINDS CONTINUE ACROSS THE REGION. UPDATE THIS MORNING IS MAINLY FOR A MORE OPTIMISTIC CLOUD COVER AND ADJUSTMENT OF LINGERING UPSLOPE SNOW SHOWERS AS WELL AS TO REMOVE MORNING WORDING. SKY COVER CHANGES WILL HAVE LITTLE IMPACT ON THE WORDING TEXT OVERALL...MAYBE A FEW MOSTLY SUNNY TO SUNNY CHANGES. BASED ON SATELLITE TRENDS...UPSLOPE SNOW SHOWERS ARE DISSIPATING FROM SOUTH TO NORTH...SO HAVE REMOVED THE SHOWERS FROM HIGHLAND AND PENDLETON COUNTY. UPDATES WILL BE OUT SHORTLY. && .PREV DISCUSSION... /ISSUED 906 AM EST FRI FEB 16 2007/ SHORT TERM /REST OF TODAY/... QUICK UPDATE THIS MORNING TO ALLOW THE WIND CHILL ADVISORY TO EXPIRE. TEMPERATURES HAVE WARMED ENOUGH TO KEEP WIND CHILL VALUES ABOVE CRITERIA. WILL MOST HAVE UPDATE AROUND NOON FOR THE DISSIPATING UPSLOPE SNOW SHOWERS AND TO REMOVE ADDITIONAL MORNING WORDING. PREV DISCUSSION... /ISSUED 310 AM EST FRI FEB 16 2007/ SHORT TERM /TODAY THROUGH TONIGHT/... WATER VAPOR LOOP SHOWS A DEEPENING UPPER LOW NEARING THE CANADIAN MARITIMES...AS A SHORT WAVE MOVES EAST INTO THE TENNESSEE VALLEY. ACARS 400-250MB WIND OBSERVATIONS SHOW A 190-210KT SOUTHWESTERLY JET FROM THE GULF STATES THROUGH THE CAROLINAS. 04Z SURFACE ANALYSIS PLACED A DECAYING COLD FRONT ACROSS THE GULF STATES. A 1033MB ANTICYCLONE DOMINATED THE CENTRAL CONUS. STRATO-CU GENERATED BY COLD ADVECTION ACROSS THE GREAT LAKES IS AFFECTING THE MOUNTAINS AND MARYLAND/WEST VIRGINIA PAN HANDLE REGION EARLY THIS MORNING. EXPECT DISSIPATING TREND THROUGH THE DAY AS ANTICYCLONIC FLOW BUILDS NORTHEAST ACROSS THE LOWER GREAT LAKES BEHIND THE SHORT WAVE. THE APPROACH OF THE SHORT WAVE WILL SERVE TO ALLOW MID AND UPPER LEVEL CLOUDS TO DEVELOP ALONG THE UPPER LEVEL JET AXIS EARLY THIS MORNING ACROSS THE SOUTHEAST ZONES...BEFORE THE JET AXIS PUSHES SOUTHEAST OF THE REGION. PRESSURE GRADIENT WILL SUPPORT SOME WIND GUSTS OF 20 MPH TODAY. WITH THE CORE OF THE COLD AIR ALOFT WILL BE PROGRESSING TO THE NORTHEAST...EXPECT HIGH TEMPERATURES ABOUT A CATEGORY WARMER THAN YESTERDAY. ANTICIPATE CLEAR TO MOSTLY CLEAR CONDITIONS TONIGHT IN BETWEEN TWO SYSTEMS. WINDS WILL DECOUPLE WITH THE SURFACE RIDGE AXIS ACROSS THE MID ATLANTIC. GIVEN A DRY ATMOSPHERE...CLEAR SKIES...AND SNOW/SLEET PACK...EXPECT TEMPERATURES TO FALL QUICKLY. THE EXCEPTION SHOULD BE IN THE HIGHER TERRAIN ABOVE 2500FT WHERE COUPLED FLOW CONTINUES TO CARRY WARMER AIR ALOFT INTO THE REGION. AVIATION... COLD ADVECTION STRATO-CU WILL AFFECT MAINLY KMRB AND POSSIBLY KIAD DURING THE MORNING...BEFORE DISSIPATING. GRADIENT WILL SUPPORT WIND GUSTS AROUND 20KTS AFTER DAYBREAK. MARINE... 00Z MET/MAV MOS AT THOMAS POINT INDICATE SUSTAINED WINDS JUST ABOVE 15 KNOTS TODAY...AND NEAR 10 KNOTS TONIGHT. PROXIMITY 00Z NAM/GFS BUFKIT FORECAST SOUNDINGS INDICATE 20-25KT WIND GUST POTENTIAL THROUGH THIS EVENING. ICE COVERAGE ACROSS THE EXTREME NORTHERN BAY IS CLOSE TO 7-9 TENTHS. SMALL CRAFT ADVISORIES WILL BE LIKELY SUNDAY INTO MONDAY WITH MORE COLD ADVECTION AND STRONG WINDS MOVING IN BEHIND A PAIR OF SHORT WAVES THIS WEEKEND. TIDES... CURRENT TIDAL DEPARTURES ARE A FOOT TO A FOOT AND A HALF BELOW ASTRONOMICAL PREDICTIONS...DUE TO A RECENT BLOWOUT. THE LUNAR CYCLE IS WANING TO A NEW MOON (3 PERCENT FULL). THE CHESAPEAKE BAY OPERATIONAL FORECAST SYSTEM AND THE NOAA EXTRATROPICAL STORM SURGE MODEL MAINTAIN CURRENT TIDAL DEPARTURES THROUGH THIS AFTERNOON. LONG TERM /SATURDAY THROUGH THURSDAY/... THIS WEEKEND A PAIR OF CLIPPER SHORT WAVES WILL MOVE THROUGH THE NW FLOW AROUND THE EASTERN UPPER TROUGH. THE FIRST WILL BEGIN MOVING IN SATURDAY MORNING ALTHOUGH THE BULK OF IT WILL AFFECT US SAT AFTERNOON INTO SAT NIGHT. THE WAVE ACTUALLY PASSES JUST S OF US SO THERE IS A CHC OF LIGHT PRECIP. ALSO THERE IS A FAIR AMOUNT OF MID LVL MOISTURE WITH IT FOR A CLIPPER. TEMPS ARE CERTAINLY COLD ENOUGH THAT THERE WILL BE NO QUESTION ANYTHING WILL BE SNOW. LOWEST LVLS OF THE ATMOS ARE DRY HOWEVER AND ANY SNOW WILL HAVE TO OVERCOME THAT...ESP OVER THE LOW LANDS. WILL HAVE CHC POPS FOR MOST EXCEPT LIKELY IN THE MOUNTAINS AND DEF SNOW ON THE UPSLOPE SIDE. LATE SUNDAY ANOTHER WEAKER CLIPPER COMES THROUGH...THE LAST ONE. THAT HAS A MORE COMPACT SHAPE TO THE VORTICITY...BUT MOISTURE APPEARS TO BE LACKING FOR NOW. AFTER THAT...A MODERATION TREND IS IN ORDER AS THE UPPER FLOW BECOMES MORE ZONAL THROUGH 240 HOURS. TOWARD MID WEEK A STATIONARY FRONT TAKES UP RESIDENCE OVER THE AREA WHICH WOULD BRING A CHC OF RAIN WITH IT STREAMING UP ALONG THE FRONT FROM SW TO NE AND OVER THE MID ATLANTIC. && .LWX WATCHES/WARNINGS/ADVISORIES... DC...NONE. MD...NONE. VA...NONE. WV...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 10 PM EST THIS EVENING FOR ANZ530>537. && $$ SHORT TERM...SAR
AREA FORECAST DISCUSSION
NWS BALTIMORE MD/WASHINGTON DC
906 AM EST FRI FEB 16 2007 .SHORT TERM /REST OF TODAY/... QUICK UPDATE THIS MORNING TO ALLOW THE WIND CHILL ADVISORY TO EXPIRE. TEMPERATURES HAVE WARMED ENOUGH TO KEEP WIND CHILL VALUES ABOVE CRITERIA. WILL MOST HAVE UPDATE AROUND NOON FOR THE DISSIPATING UPSLOPE SNOW SHOWERS AND TO REMOVE ADDITIONAL MORNING WORDING. && .PREV DISCUSSION... /ISSUED 310 AM EST FRI FEB 16 2007/ SHORT TERM /TODAY THROUGH TONIGHT/... WATER VAPOR LOOP SHOWS A DEEPENING UPPER LOW NEARING THE CANADIAN MARITIMES...AS A SHORT WAVE MOVES EAST INTO THE TENNESSEE VALLEY. ACARS 400-250MB WIND OBSERVATIONS SHOW A 190-210KT SOUTHWESTERLY JET FROM THE GULF STATES THROUGH THE CAROLINAS. 04Z SURFACE ANALYSIS PLACED A DECAYING COLD FRONT ACROSS THE GULF STATES. A 1033MB ANTICYCLONE DOMINATED THE CENTRAL CONUS. STRATO-CU GENERATED BY COLD ADVECTION ACROSS THE GREAT LAKES IS AFFECTING THE MOUNTAINS AND MARYLAND/WEST VIRGINIA PAN HANDLE REGION EARLY THIS MORNING. EXPECT DISSIPATING TREND THROUGH THE DAY AS ANTICYCLONIC FLOW BUILDS NORTHEAST ACROSS THE LOWER GREAT LAKES BEHIND THE SHORT WAVE. THE APPROACH OF THE SHORT WAVE WILL SERVE TO ALLOW MID AND UPPER LEVEL CLOUDS TO DEVELOP ALONG THE UPPER LEVEL JET AXIS EARLY THIS MORNING ACROSS THE SOUTHEAST ZONES...BEFORE THE JET AXIS PUSHES SOUTHEAST OF THE REGION. PRESSURE GRADIENT WILL SUPPORT SOME WIND GUSTS OF 20 MPH TODAY. WITH THE CORE OF THE COLD AIR ALOFT WILL BE PROGRESSING TO THE NORTHEAST...EXPECT HIGH TEMPERATURES ABOUT A CATEGORY WARMER THAN YESTERDAY. ANTICIPATE CLEAR TO MOSTLY CLEAR CONDITIONS TONIGHT IN BETWEEN TWO SYSTEMS. WINDS WILL DECOUPLE WITH THE SURFACE RIDGE AXIS ACROSS THE MID ATLANTIC. GIVEN A DRY ATMOSPHERE...CLEAR SKIES...AND SNOW/SLEET PACK...EXPECT TEMPERATURES TO FALL QUICKLY. THE EXCEPTION SHOULD BE IN THE HIGHER TERRAIN ABOVE 2500FT WHERE COUPLED FLOW CONTINUES TO CARRY WARMER AIR ALOFT INTO THE REGION. AVIATION... COLD ADVECTION STRATO-CU WILL AFFECT MAINLY KMRB AND POSSIBLY KIAD DURING THE MORNING...BEFORE DISSIPATING. GRADIENT WILL SUPPORT WIND GUSTS AROUND 20KTS AFTER DAYBREAK. MARINE... 00Z MET/MAV MOS AT THOMAS POINT INDICATE SUSTAINED WINDS JUST ABOVE 15 KNOTS TODAY...AND NEAR 10 KNOTS TONIGHT. PROXIMITY 00Z NAM/GFS BUFKIT FORECAST SOUNDINGS INDICATE 20-25KT WIND GUST POTENTIAL THROUGH THIS EVENING. ICE COVERAGE ACROSS THE EXTREME NORTHERN BAY IS CLOSE TO 7-9 TENTHS. SMALL CRAFT ADVISORIES WILL BE LIKELY SUNDAY INTO MONDAY WITH MORE COLD ADVECTION AND STRONG WINDS MOVING IN BEHIND A PAIR OF SHORT WAVES THIS WEEKEND. TIDES... CURRENT TIDAL DEPARTURES ARE A FOOT TO A FOOT AND A HALF BELOW ASTRONOMICAL PREDICTIONS...DUE TO A RECENT BLOWOUT. THE LUNAR CYCLE IS WANING TO A NEW MOON (3 PERCENT FULL). THE CHESAPEAKE BAY OPERATIONAL FORECAST SYSTEM AND THE NOAA EXTRATROPICAL STORM SURGE MODEL MAINTAIN CURRENT TIDAL DEPARTURES THROUGH THIS AFTERNOON. LONG TERM /SATURDAY THROUGH THURSDAY/... THIS WEEKEND A PAIR OF CLIPPER SHORT WAVES WILL MOVE THROUGH THE NW FLOW AROUND THE EASTERN UPPER TROUGH. THE FIRST WILL BEGIN MOVING IN SATURDAY MORNING ALTHOUGH THE BULK OF IT WILL AFFECT US SAT AFTERNOON INTO SAT NIGHT. THE WAVE ACTUALLY PASSES JUST S OF US SO THERE IS A CHC OF LIGHT PRECIP. ALSO THERE IS A FAIR AMOUNT OF MID LVL MOISTURE WITH IT FOR A CLIPPER. TEMPS ARE CERTAINLY COLD ENOUGH THAT THERE WILL BE NO QUESTION ANYTHING WILL BE SNOW. LOWEST LVLS OF THE ATMOS ARE DRY HOWEVER AND ANY SNOW WILL HAVE TO OVERCOME THAT...ESP OVER THE LOW LANDS. WILL HAVE CHC POPS FOR MOST EXCEPT LIKELY IN THE MOUNTAINS AND DEF SNOW ON THE UPSLOPE SIDE. LATE SUNDAY ANOTHER WEAKER CLIPPER COMES THROUGH...THE LAST ONE. THAT HAS A MORE COMPACT SHAPE TO THE VORTICITY...BUT MOISTURE APPEARS TO BE LACKING FOR NOW. AFTER THAT...A MODERATION TREND IS IN ORDER AS THE UPPER FLOW BECOMES MORE ZONAL THROUGH 240 HOURS. TOWARD MID WEEK A STATIONARY FRONT TAKES UP RESIDENCE OVER THE AREA WHICH WOULD BRING A CHC OF RAIN WITH IT STREAMING UP ALONG THE FRONT FROM SW TO NE AND OVER THE MID ATLANTIC. && .LWX WATCHES/WARNINGS/ADVISORIES... DC...NONE. MD...NONE. VA...NONE. WV...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 10 PM EST THIS EVENING FOR ANZ530>537. && $$ SHORT TERM UPDATE...SAR PREV DISCUSSION...ROGOWSKI/STRONG

AREA FORECAST DISCUSSION
NWS MARQUETTE MI
440 PM EST FRI FEB 16 2007 .SHORT TERM (TONIGHT AND SAT)... LARGE SCALE PATTERN WITH RIDGE OVR PACIFIC AND TROUGH OVR EASTERN CANADA SHOWING SIGNS OF EASING. CENTER OF TROUGH NOW NEAR LABORADOR WHILE STRONG SHORTWAVE TROUGH OFF THE WEST CONUS OVR N PACIFIC CONTINUES EAST TOWARD THE RIDGE. NW FLOW ALOFT STILL IN PLACE FM CNTRL CANADA INTO MUCH OF CNTRL CONUS. AFTER BRIEF SHOT OF ARCTIC AIR MOVING INTO UPR LAKES THIS WEEKEND...DEVELOPING ZONAL FLOW WILL BRING IN A WARMER PATTERN NEXT WEEK. IN THE MEANTIME...EXPECT ISOLD SNOW SHOWERS AND FLURRIES TONIGHT DUE TO WARM AIR ADVECTION ONGOING ALOFT. DRY AIR SEEN ON EARLY AFTN TAMDAR FM KSAW CONTINUES TO LIMIT COVERAGE OF THE PCPN. EVENTUALLY LATE TONIGHT INTO SAT WILL HAVE COLD ADVECTION/LES ISSUES TO BATTLE. THE WARMER TEMPS AT SFC TODAY THANKS TO SW WINDS OUT AHEAD OF LOW PRES TROUGH DROPPING INTO MN. TEMPS IMMEDIATELY BEHIND THE TROUGH NOT TOO DIFFERENT FM THOSE AHEAD OF IT. COLDER AIR LAGS WELL BEHIND THE FRONT. JUST ALOFT THOUGH...TEMPS FM H9-H85 COOL STEADILY THROUGH SAT AND THIS WILL HELP RAMP UP LES LATE TONIGHT. LARGE SCALE FEATURES ARE PRETTY MINIMAL THROUGH SAT. THERE IS A SHORTWAVE CURRENTLY OVR MANITOBA BUT MAIN LIFT WITH THE FEATURE MISS UPR MI TO THE N. UKMET/GFS INITIALIZED BEST WITH THE FEATURE...AND GFS SOUNDINGS SHOW INVERSION HEIGHT RESPONDS LITTLE TO THE WAVE. SO...EXPECT MOSTLY PURE LES AFTER TROUGH MOVES THROUGH LATE TONIGHT. TEMPS AT TOP OF INVERSION ARE FAVORABLE FOR BEST SNOW GROWTH SO MODERATE ACCUMS ARE EXPECTED IN NW FLOW CONVERGENCE AREAS OF ECNTRL UPR MI. INHERITED A LES WATCH FOR SAT THROUGH SUN. WHAT TO DO WITH THIS HEADLINE AND WHETHER TO POST ANY ADDITIONAL LES HEADLINES WAS MAIN CONCERN OF THE SHORT TERM. SOUNDINGS SHOW CONDITIONS BECOME MORE FAVORABLE FOR HEAVY LES SAT NIGHT INTO SUN SO THAT IS WHEN THE VERY HEAVY SNOW WILL LIKELY OCCUR. HOWEVER...SINCE THERE WILL BE AT LEAST LOCALLY HEAVY LES ON SAT WENT AHEAD AND BEGAN WARNING LATE TONIGHT FOR THE PREVIOUS WATCH AREA. NW WINDS FAVOR WESTERN LUCE FOR MODERATE ACCUMS ON SAT THEN BECOME UNFAVORABLE SAT NIGHT AS WINDS BECOME MORE NORTHERLY. RELATIVELY SHORT DURATION TO THE LES...SO ONLY ISSUED AN ADVY FOR LUCE. .LONG TERM (SAT NIGHT THRU FRI)... PERIOD OF HEAVIEST LES WILL OCCUR SAT NIGHT OVER ALGER/NRN SCHOOLCRAFT AND POSSIBLY FAR NW LUCE COUNTIES AS SHORTWAVE RACES SE ACROSS THE UPPER GREAT LAKES. GFS/NAM FCST SOUNDINGS SHOW THE RESPONSE TO SHORTWAVE AS INVERSION HEIGHTS RISE FROM AROUND 5KFT TO 7-8KFT. INCREASING LAND BREEZE COMPONENT TO WIND OFF ONTARIO SHOULD FOCUS MAIN LES MOSTLY TO THE W OF LUCE COUNTY AS THE NIGHT PROGRESSES. IN FACT...WOULD NOT BE SURPRISED TO SEE SHSN END OVER ALL BUT THE FAR NW PART OF THE COUNTY. CONVERGENCE WILL BECOME INCREASINGLY FOCUSED OVER ALGER COUNTY...AND WITH SHORTWAVE SUPPORT IN THE EVENING AND DECENT INTERSECTION OF UPWARD MOTION WITH FAVORABLE DENDRITIC SNOW GROWTH TEMPS...WOULD NOT BE SURPRISED TO SEE UP TO 8 INCHES OF SNOW ACCUMULATION JUST DURING SAT NIGHT. ADVY TYPE ACCUMULATIONS MAY OCCUR OVER PARTS OF NE DELTA/SRN SCHOOLCRAFT COUNTY SAT NIGHT...BUT THIS WILL DEPEND LARGELY ON WHETHER ONE OR TWO DOMINATE BANDS CAN TAKE SHAPE. CLOUDS HAVE PREVENTED A LOOK AT THE ICE COVER OVER WRN LAKE SUPERIOR TODAY...BUT ICE APPEARED TO BE FAIRLY EXTENSIVE IN RECENT DAYS. EVEN SO...ICE COVER AWAY FROM BAYS AND PROTECTED AREAS TENDS TO SHIFT QUITE A BIT WITH ANY KIND OF DECENT WIND...SO THERE IS NO WAY REALLY TO KNOW WHAT THE COVERAGE WILL BE SAT NIGHT. FOR NOW...WILL ASSUME ICE COVER WILL PLAY A ROLE IN LIMITING LES...HOLDING ACCUMULATIONS TO JUST A FEW INCHES. GOGEBIC COUNTY SHOULD BE IMPACTED MOST BY THE LIMITING AFFECTS OF THE ICE COVER. LES WILL WIND DOWN FROM W TO E SUN AS SFC HIGH PRES RIDGE APPROACHES...INVERSIONS FALL TO 3-5KFT...AND DRIER AIR ARRIVES. PATTERN CHANGE WILL BE UNDERWAY EARLY NEXT WEEK AS FLOW GOES ZONAL...CUTTING OFF ARCTIC AIR AND SPREADING PACIFIC AIR ACROSS THE CONUS. THE WARM UP WILL BE INITIATED BY A SHORTWAVE HEADING ALONG THE U.S./CANADA BORDER MON/TUE. BEFORE THAT HAPPENS...SFC HIGH PRES RIDGE WILL QUICKLY SLIDE ACROSS UPPER MI SAT EVENING. THIS WILL BRING AN END TO -SHSN OVER THE NE FCST SAT EVENING...AND IT WILL PROVIDE AN OPPORTUNITY FOR TEMPS TO PLUMMET EARLY AS WINDS DROP TO LIGHT/CALM. HOW MUCH TEMPS FALL WILL BE THE QUESTION AS RETURN FLOW QUICKLY DEVELOPS AFTER RIDGE PASSAGE...AND MID/HIGH CLOUDS BEGIN INCREASING IN DEVELOPING STRONG WAA/ISENTROPIC ASCENT PATTERN. HAVE OPTED TO GO A BIT BLO GUIDANCE (AROUND 0F) OVER THE E HALF OF FCST AREA WHERE THERE MAY BE A BETTER OVERLAP OF LIMITED CLOUD COVER AND LIGHT/CALM WINDS. TEMPS SHOULD STEADY OUT AND THEN RISE SOME OVERNIGHT...AND HAVE INDICATED SUCH A TREND IN HRLY TEMP GRIDS. SOME -SN WILL PROBABLY DEVELOP IN THE WAA/ISENTROPIC ASCENT REGIME...BUT THERE IS ALWAYS THE DIFFICULTY IN DETERMINING WHEN THE DRY LOW-LEVELS WILL MOISTEN SUFFICIENTLY TO ALLOW SNOW TO REACH THE GROUND. HAVE INCLUDED CHC POPS AFTER MIDNIGHT...BUT THAT MAY BE A BIT TOO QUICK. WITH WAA REGIME CONTINUING MON...HAVE MAINTAINED GOING FCST OF CHC/SLIGHT CHC POPS. GUIDANCE LOOKED A BIT TOO AMBITIOUS WITH WARM UP ON MON...SO KEPT TEMPS A COUPLE OF DEGREES LWR THAN GUIDANCE. TUE THRU FRI...THIS WILL DEFINITELY BE A WARMER PERIOD THAN HAS BEEN THE CASE THE LAST COUPLE OF WEEKS (TEMPS SHOULD BE ABOVE NORMAL EACH DAY). PROJECTED PATTERN IS SOMEWHAT REMINISCENT OF THE MILD SPLIT FLOW PATTERN THAT DOMINATED EARLIER IN THE WINTER. MAIN ACTION WILL BE CONFINED TO THE SOUTHERN CONUS...LEAVING UPPER MI WITH VERY LIMITED PCPN CHANCES AS NRN STREAM SYSTEMS PASS MOSTLY TO THE N OF HERE. SO THE LACK OF SIGNIFICANT COLD SEASON SYNOPTIC PCPN FOR THE AREA WILL CONTINUE. THERE HAVE BEEN SOME HINTS THAT A MORE ACTIVE PATTERN MAY DEVELOP BEYOND THIS PERIOD WITH THE POTENTIAL FOR SIGNIFICANT PCPN PRODUCING SYSTEMS TO MOVE FROM THE SW STATES INTO THE GREAT LAKES REGION. IN THE MEANTIME...ROUGH CONSENSUS OF THE MEDIUM RANGE MODELS SUGGESTS ONE SHORTWAVE WILL BE EXITING THE AREA TUE WITH ANOTHER APPROACHING MIDWEEK. AS ALWAYS...TIMING WILL BE UNCERTAIN...AND THIS IS ILLUSTRATED BY THE ECWMF BEING ABOUT 12HRS OR SO FASTER WITH THE MIDWEEK SYSTEM THAN GFS AND CANADIAN MODEL. WILL LEAN TOWARD THE ECMWF WHICH WAS INCORPORATED TO A LARGE DEGREE INTO HPC GUIDANCE. IN ANYCASE...PCPN CHANCES WILL BE MINIMAL WITH BOTH SYSTEMS. IN FACT...WILL ONLY CARRY A MENTION OF -SN/FLURRIES TUE AS TRACK OF NEXT SHORTWAVE SHOULD BE FAR ENOUGH N TO KEEP ANY WAA PCPN ASSOCIATED WITH IT TO THE N OF HERE. DRY WEATHER SHOULD THEN CONTINUE THRU FRI. LES WILL BE ABSENT DURING THIS ENTIRE PERIOD AS AIRMASS WILL BE TOO WARM. LATE IN THE WEEK...WILL WATCH FOR A TROF MOVING ONSHORE OVER THE W COAST TO INITIATE LOW PRES DEVELOPMENT OVER THE SRN ROCKIES PER GFS/ECMWF RUNS. IT WILL EVENTUALLY TURN INTO A MAJOR PCPN PRODUCER THAT COULD TRACK INTO THE GREAT LAKES REGION JUST BEYOND THIS FCST PERIOD PER RECENT ECMWF RUNS. && .MQT WATCHES/WARNINGS/ADVISORIES... LAKE EFFECT SNOW WARNING FROM 4 AM SAT TO 7 PM EST SUN MIZ006-085. LAKE EFFECT SNOW ADVISORY FROM 4 AM SAT TO 1 AM EST SUN MIZ007. && $$ ROLFSON
AREA FORECAST DISCUSSION
NWS ALBUQUERQUE NM
249 PM MST FRI FEB 16 2007 .DISCUSSION... 18Z SURFACE ANALYSIS SHOWS A LEE TROUGH EXTENDING FROM THE PERMIAN BASIN NORTH THROUGH THE EASTERN PLAINS OF NEW MEXICO TO AN AREA OF LOW PRESSURE OVER EASTERN COLORADO. LATEST WATER VAPOR LOOP SHOWS A VERY LARGE UPPER LEVEL WAVE OVER THE CENTRAL PLAINS STATES MOVING SOUTHEAST TOWARD THE MIDWEST. 400-200MB AIRCRAFT WIND DATA SHOWS A 110-130 KNOT JET TRANSLATING SOUTHEAST ACROSS THE CENTRAL ROCKIES ALONG THE BACKSIDE OF THE UPPER LEVEL WAVE. CURRENT OBSERVATIONS TO THE LEE OF THE CENTRAL MOUNTAIN CHAIN INDICATE WINDS ARE JUST BELOW WIND ADVISORY CRITERIA...EXCEPT LOCALLY AT CLINES CORNERS WHICH WAS GUSTING UP TO 48 MPH EARLIER THIS AFTERNOON. EXPECT GUSTY WINDS TO CONTINUE IN MANY AREAS THROUGH SUNSET AS THE SURFACE PRESSURE GRADIENT SLOWLY DECREASES OVER THE EASTERN PLAINS. 12Z MREF AND 15Z SREF GUIDANCE ALONG WITH 12Z NAM/GFS/UKMET/ECMWF CONTINUE TO SHOW A MID AND UPPER LEVEL RIDGE DEVELOPING OVER THE STATE THROUGH SUNDAY AFTERNOON. A BRIEF SURFACE COLD FRONT WILL SWING INTO THE NORTHEAST CORNER OF THE STATE LATE TONIGHT INTO SATURDAY BRINGING TEMPS DOWN 15-20 DEGREES FROM THIS AFTERNOON. LEE TROUGHING WILL DEVELOP ONCE AGAIN SUNDAY REBOUNDING TEMPS INTO THE 60S ACROSS MUCH OF THE NORTHEAST. HIGH CLOUDINESS WILL SPREAD OVER THE STATE FROM THE SOUTHWEST LATE SUNDAY AHEAD OF A DISORGANIZED UPPER LEVEL DISTURBANCE MOVING IN FROM THE BAJA. THIS SYSTEM WILL LIKELY SERVE ONLY TO MOISTEN THE MID AND UPPER LEVELS OF THE ATMOSPHERE AHEAD OF A MORE POTENT SYSTEM SLATED TO MOVE INTO THE DESERT SOUTHWEST LATE MONDAY AND TUESDAY. ENSEMBLE GUIDANCE IS ALREADY INDICATING GOOD AGREEMENT WITH THIS SYSTEM. BEST POPS WILL BE LATE MONDAY INTO TUESDAY AND 700MB TEMPS WILL BE COLD ENOUGH TO PRODUCE YET ANOTHER ROUND OF VALLEY RAIN SHOWERS AND WELCOME MOUNTAIN SNOWS. && .PRELIMINARY POINT TEMPS/POPS... FARMINGTON...................... 24 51 24 52 / 0 0 0 5 GALLUP.......................... 18 50 19 53 / 0 0 0 5 GRANTS.......................... 21 50 21 53 / 0 0 0 5 GLENWOOD........................ 32 64 34 65 / 0 0 0 10 CHAMA........................... -3 40 2 43 / 5 0 0 0 LOS ALAMOS...................... 16 45 16 46 / 0 0 0 0 RED RIVER....................... 4 36 9 40 / 5 0 0 0 TAOS............................ 13 44 11 47 / 0 0 0 5 SANTA FE........................ 20 43 20 47 / 0 0 0 5 SANTA FE AIRPORT................ 22 46 18 49 / 0 0 0 5 ESPANOLA........................ 17 49 15 50 / 0 0 0 5 ALBUQUERQUE HEIGHTS............. 29 53 29 55 / 0 0 0 5 ALBUQUERQUE VALLEY.............. 24 55 26 57 / 0 0 0 5 ALBUQUERQUE FOOTHILLS........... 28 51 27 53 / 0 0 0 5 ALBUQUERQUE WEST MESA........... 28 52 28 54 / 0 0 0 5 SOCORRO......................... 30 58 29 58 / 0 0 0 5 SANDIA PARK/CEDAR CREST......... 21 48 22 48 / 0 0 0 5 MORIARTY/ESTANCIA............... 17 46 20 50 / 0 0 0 0 CARRIZOZO....................... 28 55 30 55 / 0 0 0 0 RUIDOSO......................... 26 48 28 50 / 0 0 0 0 RATON........................... 17 44 17 50 / 0 0 0 0 LAS VEGAS....................... 20 44 21 51 / 0 0 0 5 ROY............................. 25 45 27 55 / 0 0 0 0 CLAYTON......................... 23 43 26 58 / 0 0 0 0 SANTA ROSA...................... 24 51 29 61 / 0 0 0 0 TUCUMCARI....................... 20 49 27 60 / 0 0 0 0 FORT SUMNER..................... 28 54 28 63 / 0 0 0 0 CLOVIS.......................... 19 51 27 62 / 0 0 0 0 PORTALES........................ 18 52 26 61 / 0 0 0 0 ROSWELL......................... 27 56 30 63 / 0 0 0 0 && .ABQ WATCHES/WARNINGS/ADVISORIES... NONE. && $$ GUYER