Forecast Discussions mentioning "ACARS", "MDCRS", "AIRCRAFT", "TAMDAR", or "AMDAR" received at FSL on 03/03/07

AREA FORECAST DISCUSSION
NWS SAN DIEGO CA
935 AM PST FRI MAR 2 2007 .SYNOPSIS... BUILDING HIGH PRESSURE ALOFT AND DEVELOPING SANTA ANA CONDITIONS WILL BRING WARMER WEATHER THIS WEEKEND. GUSTY NORTHEAST WINDS WILL INCREASE THROUGH AND BELOW THE SOME MOUNTAIN PASSES TODAY...AND A WIND ADVISORY IS IN EFFECT IN SAN BERNARDINO COUNTY UNTIL 2 PM. STRONGER...POTENTIALLY DAMAGING SANTA ANA WINDS WILL ARRIVE LATE TONIGHT AND CONTINUE THROUGH SUNDAY. THE WEATHER WILL BE MUCH WARMER THIS WEEKEND...ESPECIALLY WEST OF THE MOUNTAINS WHERE RECORD HIGHS ARE WITHIN REACH. ONSHORE FLOW WILL RETURN EARLY NEXT WEEK BRINGING COOLER WEATHER. && .DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE... SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO COUNTIES... .SHORT TERM...TODAY THROUGH SUNDAY... FIRST PULSE OF DEVELOPING SANTA ANA WIND EVENT HAS ARRIVED OVER SAN BERNARDINO MOUNTAINS AND INLAND EMPIRE. RECENT ACARS OBSERVATIONS AND 12Z NAM12 MODEL SHOW NORTHEAST 25-35 KT WIND CAJON PASS TO SANTA ANA RIVER VALLEY BETWEEN 2500-10000 FEET SAN BERNARDINO COUNTY THIS MORNING. WIND GUST PROGRAM BASED ON MORNING SOUNDINGS SUPPORT GUSTS BETWEEN 40 AND 50 MPH. CURRENT WIND ADVISORY LOOKS GOOD MENTIONINNG GUSTS OVER 45 MPH SO NO CHANGES PLANNED. A SECOND PULSE ARRIVES THIS EVENING AND BROADENS AND STRENGTHENS DURING THE NIGHT INTO MID MORNING HOURS SATURDAY AS UPPER LEVEL HIGH PRESSURE RIDGE BUILDS ALONG 125 WEST LONGITUDE AND SURFACE HIGH BUILDS TO +1040 MB OVER NORTHEAST UTAH.. THIS YIELDS AN OFFSHORE PRESSURE GRADIENT OF 23 MB SATURDAY MORNING...SO SUSTAINED NORTHEAST WINDS 35 TO 45 MPH WITH GUSTS 60 TO 80 MPH DURING THE PEAK OF THIS EPISODE ARE ANTICIPATED. THE PRESSURE GRADIENT TEMPORARILY WEAKENS TO 15 MB MID DAY SATURDAY AND THE RIDGE ALOFT MOVES ONSHORE AT THIS TIME. THESE SYNOPTIC CHANGES COUPLED WITH THE DIURNAL HEATING SHOULD TEMPORARILY WEAKEN THE WINDS..DROPPING DOWN TO ADVISORY STRENGTH IN MOST LOCATIONS. THE THIRD AND FINAL SHOT ARRIVES SATURDAY NIGHT/SUNDAY MORNING WHEN SURFACE PRESSURE GRADIENT RESTRENGTHENS TO AROUND 19 MB. THIS FINAL IMPULSE SHOULD MAINLY EFFECT RIVERSIDE/SAN DIEGO COUNTIES DUE TO SURFACE HIGH PRESSURE CELL SLIPPING SOUTHEASTWARD AND THE WEAKENED SUBSIDENCE ALOFT CAUSED BY THE UPPER LEVEL RIDGE MOVING EAST BETWEEN 115-110 WEST LONGITUDE. FOR THIS THIRD PERIOD SUSTAINED EAST 25-40 MPH WITH GUSTS 60 MPH ARE ANTICIPATED. CURRENTLY THERE IS A HIGH WIND WATCH OUT FOR ALL THE MOUNTAINS AND VALLEYS FROM 4 AM SATURDAY THROUGH 2 PM SUNDAY. WILL BE UPGRADING THIS TO A WARNING IN THE AFTERNOON FORECAST PACKAGE BUT WITH DIFFERENT START AND STOP TIMES FOR THE VARIOUS MOUNTAINS/VALLEYS AS THE FLOW BECOMES MORE/LESS PERPENDICULAR WITH RIDGE AXIS. CURRENT THINKING ON START/STOP TIMES ARE AS FOLLOWS... HIGH WIND WARNING SAN BERNARDINO MOUNTAINS/INLAND EMPIRE/SANTA ANA MOUNTAINS FROM 7 PM THIS EVENING UNTIL 2 PM SATURDAY AND FOLLOWUP WITH ANOTHER WIND ADVISORY FOR INLAND EMPIRE/SANTA ANA MOUNTAINS FROM 2 PM SATURDAY-2 PM SUNDAY... A HIGH WIND WARNING FOR BANNING PASS/RIVERSIDE COUNTY MOUNTAINS FROM 1 AM SATURDAY UNTIL 2 PM SUNDAY... AND A HIGH WIND WARNING FOR SAN DIEGO COUNTY MOUNTAINS/ INLAND VALLEYS FROM 4 AM SATURDAY UNTIL 2 PM SUNDAY. SATURDAY IS CURRENTLY FORECAST TO BE THE WARMEST DAY WEST OF THE MOUNTAINS AND SEVERAL RECORD HIGHS ARE WITHIN REACH OVER SAN DIEGO COUNTY...WHILE ELSEWHERE TEMPERATURES WILL RANGE 10-15 DEGREES ABOVE NORMAL. SUNDAY COULD BE JUST AS WARM...THE MITIGATING FACTOR IS HOW MUCH SUNSHINE WILL BE BLOCKED BY THE UPPER LEVEL MOISTURE BROUGHT IN FROM THE SOUTHWEST BY THE APPROACHING SUBTROPICAL UPPER LEVEL TROUGH. .FIRE WEATHER... THE DRY OFFSHORE FLOW AND WARM WEATHER WILL INCREASE THE FIRE WEATHER POTENTIAL...BUT THE RECENT RAIN AND MOUNTAIN SNOW HAS ELEVATED THE FUEL MOISTURE. WILL CONTINUE TO MONITOR THE FIRE SITUATION...BUT IT APPEARS THAT THE HIGHEST THREAT WILL BE SUNDAY AFTER A 24-36 HOUR PERIOD OF DRY SANTA ANA WINDS LOWERS THE FUEL MOISTURE CONTENT SUFFICIENTLY. VERY DRY CONDITIONS WILL CONTINUE INTO MONDAY OVER THE MOUNTAINS AND DESERT AND THE WINDS WILL BE SHIFTING TO THE SOUTH AND INCREASING AS A TROUGH MOVES INLAND. AT THIS TIME NO FIRE WEATHER WATCH IS ANTICIPATED. && .LONG TERM...MONDAY THROUGH FRIDAY THE AFOREMENTIONED TROUGH MOVING INLAND ON MONDAY WILL GENERATE INCREASING MID AND HIGH LEVEL CLOUDS AS WELL AS SOME STRATUS/FOG ACROSS COAST AND VALLEYS...HOWEVER THE LAYER BETWEEN 2500 AND 8000 FEET REMAINS VERY DRY...SO ANY PRECIPITATION THAT MIGHT GET GENERATED BY LIFTING OF THE MID LEVEL MOISTURE WILL EVAPORATE BEFORE REACHING THE GROUND AND THE MARINE LAYER WILL NOT HAVE A STRONG SUBSIDENCE INVERSION IN PLACE PRIOR THAT WOULD SUPPORT COMPLETE SATURATION LEADING TO DRIZZLE AS IT BEGINS TO LIFT. WEAK HIGH PRESSURE RIDGE BUILDS BEHIND THE TROUGH ON TUESDAY...AND LATEST MODEL TIMING HAS NEXT TROUGH MOVING ACROSS SOUTHWEST CALIFORNIA LATE WEDNESDAY/THURSDAY...STILL LOOKING TOO ANEMIC TO GENERATE PRECIPITATION...FOLLOWED BY BUILDING HIGH PRESSURE RIDGE ON FRIDAY...IN SHORT CONTINUED DRY NEXT WEEK. && .AVIATION... 021530Z...DEVELOPING OFFSHORE FLOW WILL RESULT IN LITTLE OR NO MARINE LAYER THROUGH SATURDAY. AS A RESULT...EXPECT A MOSTLY CLEAR SKY WITH UNRESTRICTED VISIBILITIES AT ALL AREA AIRPORTS THROUGH SATURDAY. THE OFFSHORE FLOW WILL RESULT IN GUSTY NORTHEAST WINDS THROUGH AND BELOW MOUNTAIN PASSES AND CANYONS WITH ASSOCIATED UP AND DOWN DRAFTS AND LOW LEVEL WIND SHEAR THROUGH SATURDAY...ESPECIALLY VICINITY KONT. && .SGX WATCHES/WARNINGS/ADVISORIES... WIND ADVISORY FOR THE SAN BERNARDINO MOUNTAINS AND INLAND EMPIRE UNTIL 2 PM. SEE LAXNPWSGX. HIGH WIND WATCH FOR ALL MOUNTAINS AND INLAND VALLEYS FROM 4 AM SATURDAY UNTIL 2 PM SUNDAY. SEE LAXNPWSGX. && $$ PUBLIC/FIRE WEATHER...BALFOUR AVIATION/MARINE.......HORTON
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
633 AM CST THU FEB 29 2007 .DISCUSSION FOR ZONES/GRIDS... 410 AM CST MAJOR LATE WINTER/EARLY SPRING STORM CONTINUES TO DEEPEN EARLY THIS MORNING. POWERFUL JET MAX MEASURED AT 160KTS ON OUN 00Z RAOB CONTINUES TO PUNCH NORTHEASTWARD ACROSS THE MID MS VALLEY...WITH CLOSED UPPER CIRCULATION NOW FORMED OVER THE EASTERN KS/NE BORDER. SURFACE LOW...CURRENTLY ON THE KS/MO BORDER...CONTINUES TO DEEPEN AS IT MOVES NORTHEAST. STRONG PRESSURE FALLS NOTED INTO CENTRAL IL WHERE WAA MAXIMIZED BUT PROGGED SLOWING AND TURN TO MORE NORTHWARD TRACK OF THE LOW ACROSS EASTERN IA LATER THIS MORNING AND THIS AFTERNOON APPEARS TO BE CORRECT NOW THAT CLOSED UPPER LOW HAS FORMED. LAREG AREA OF RAIN AND THUNDERSTORMS CONTINUES TO SPREAD ACROSS NORTHERN IL EARLY THIS MORNING AS 75KT LOW LEVEL JET PROVIDES FORCING ABOVE THE SURFACE WARM FRONT EXTENDING EASTWARD ACROSS CENTRAL IL. STRONG ISENTROPIC LIFT AND THETA-E ADVECTION THRU MID LEVELS COUPLED WITH DIVERGENCE ALOFT AT LEFT EXIT REGION OF UPPER JET RESULTING IN STRONG DEEP UVV. WITH MID LEVEL LAPSE RATES NEAR MOIST ADIABATIC CAPE ABOVE BOUNDARY LAYER LIMITED THOUGH VERTICAL EXTENT OF STRONGER CELLS AND FREEZING LEVEL ACROSS NORTHERN IL BETWEEN 8-9K FT AGL...SOME SMALL HAIL REACHING THE GROUND. WAA AREA OF RAIN TO MOVE NORTH WITH H8 FRONT PROGGED TO SOUTHERN WI AND LOWER MI BY 18Z BUT CONTINUED CONVECTIVE DEVELOPMENT UPSTREAM OCCURRING AND EXPECTED TO CONTINUE WITH DESTABALIZATION AS MID LEVELS START TO COOL AS MID-UPPER TROUGH AXIS CROSSES THE MS VALLEY. SEVERE POTENTIAL FROM CENTRL IL INTO SOUTHERN PORTION OF FA THIS AFTERNOON WHERE DESTABILIZATION WILL BE GREATEST. STRONG WIND FIELD PRESENTS DAMAGING WIND THREAT UNTIL OCCLUDED FRONT SWEEPS NORTHEASTWARD THROUGH NORTHERN IL. FROPA WILL USHER IN STRONG SW SURFACE WINDS FOR TONIGHT AND FRI...SLOWLY DROPPING OFF AS THE STACKED SYSTEM GRADUALLY WEAKENS AS IT MOVCES ACROSS THE GREAT LAKES FRI NIGHT. RADAR ESTIMATES UP TO .5 INCH RAIN FROM HEAVIER CELLS ALREADY EARLY THIS MORNING AND WITH AN ADDITIONAL 1 AVERAGE EXPECTED LATER THIS MORNING AND THIS AFTERNOON THE FLOOD WATCH WILL CONTINUE. COLD AIR RAPIDLY WRAPS AROUND THE LOW. H8 TEMPS PLUNGE FROM PLUS 7 TO PLUS 10C ACROSS THE FA AT 18Z TO MINUS 7 TO MINUS 9 BY 06Z. FROPA LATE TODAY SHOULD END MOST/ALL PRECIP BUT WITH SYSTEM SLOWING AS IT MOVES FROM IA TO SOUTHERN WI TONIGHT MOISTURE WILL ALSO WRAP AROUND THE CIRCULATION BRINGING SOME LIGHT SNOW TO THE FA LATE TONIGHT AND FRI. TRS && .AVIATION... THE FIRST ROUND OF THUNDERSTORMS WILL MOVE THROUGH BY 9 AM CST. LOOKING AT THE ACARS SOUNDING THE THUNDERSTORMS THIS MORNING ARE ELEVATED. THE LOCAL WRF ARW SHOWS THE WARM FRONT MOVING NORTH INTO THE TAF FORECAST AREA BY 21 UTC. WE CAN EXPECT MORE THUNDERSTORMS LATER TODAY. WILL HAVE A TEMPO GROUP FOR MODERATE SHOWERS FROM 15 TO 18 UTC AS THE WARM FRONT APPROACH NORTHEAST ILLINOIS. THEN A DRY SLOT MAY MOVE INTO THE AREA AS THE LOW MOVE INTO WISCONSIN AND TO MICHIGAN. AS THE COLD AIR MOVES INTO NORTHERN ILLINOIS SNOW IS EXPECTED AFTER 07 UTC. THE WIND IS NOT FORECAST TO SWITCH TO THE NORTHWEST UNTIL FRIDAY AFTERNOON. && .LOT WATCHES/WARNINGS/ADVISORIES... .IL...FLOOD WARNING PORTIONS KANKAKEE AND UPPER IL RIVERS. FLOOD WATCH THRU 12Z FRIDAY. .IN...FLOOD WARNING PORTIONS KANKAKEE RIVER. FLOOD WATCH THRU 12Z FRIDAY. .LM...GALE WARNING OPEN WATERS 09Z THURSDAY THRU 09Z FRIDAY. SMALL CRAFT ADVISORY NEARSHORE 02Z THURSDAY THRU 09Z FRIDAY. && $$
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
930 PM EST FRI MAR 2 2007 .UPDATE... STRONG WINDS AT LEX HAVE BEEN MORE PERSISTENT THAN EXPECTED EARLIER...AND HAVE ISSUED ANOTHER SPS FOR THE BLUEGRASS THROUGH 1030 PM EST TO COVER THESE GUSTS. SHOULD SEE A DIMINISHING TREND AFTERWARD. IN OTHER SECTIONS OF THE CWA WINDS HAVE SUBSIDED. AREA OF MID/HIGH LEVEL CLOUDS CURRENTLY OVER THE CWA ASSOC WITH UPPER LEVEL JET STREAK ARE PRODUCING SOME DECENT RADAR RETURNS OVER SRN/ERN PARTS OF THE CWA. EVEN IN THE PRESENCE OF 25-30 DEGREE T-TD SPREADS...FEEL THAT AT LEAST SOME SPRINKLES ARE POSSIBLE THROUGH THE EARLY OVERNIGHT PERIOD IN THESE AREAS. WILL UPDATE THE FCST TO ACCOUNT FOR THIS. BASED ON LATEST OUTPUT FROM NAM/RUC...PCPN ASSOC WITH VIGOROUS UPPER WAVE OVER MIDWEST SHOULD HOLD OFF UNTIL MID-DAY SATURDAY...WHICH IS IN-LINE WITH CURRENT FCST. UPDATED FCST OUT BY 10 PM EST. CS && .SHORT TERM (TONIGHT AND SATURDAY) SOME MAJOR PROBLEMS TO DEAL WITH IN THE SHORT TERM. FIRST AND FOREMOST IS THE STRONG AND GUSTY WINDS THIS AFTERNOON AND EVENING. A TIGHT PRESSURE GRADIENT AROUND THE DEEP GREAT LAKES LOW PRESSURE IS CAUSING WIND GUSTS FROM 40 TO 50 MPH AT TIMES ACROSS N CNTRL KY AND S CNTRL INDIANA THAT WILL DIMINISHING DURING THE EVENING HOURS. SO KEPT THE WIND ADVISORY ACROSS THE SAME AREA UNTIL 00Z TONIGHT. ON SATURDAY AS THE CLOSED 500 MB LOW OVER STARTS TO LIFT EAST NORTHEAST TOWARDS SOUTHERN CANADA...A RATHER VIGOROUS SHORT WAVE ROTATES AROUND THE SOUTH SIDE AROUND THIS CLOSED CIRCULATION AND BRINGS A BURST OF COLDER AIR THAT IS RELATIVELY MOIST IN THE LOWER LEVELS UP TO ABOUT THE 700 MB LEVEL. THERE IS ALSO SOME DECENT SYNOPTIC SCALE LIFT...SO THERE IS AT LEAST A CHANCE OF RAIN OR SNOW ON SATURDAY. WILL GO WITH 30 PERCENT NRN TWO THIRDS OF FA AND 20 PCT ACROSS THE SOUTH. WITH INCREASED CLOUDS AND PCPN THREAT ALONG WITH GOOD COLD AIR ADVECTION...WILL GO WITH MAX TEMPS A FEW DEGS BELOW THE MAV FCSTS FOR SATURDAY. THIS AGREES WELL WITH IND..ILN AND PAH FCSTS TOO. --21 .LONG TERM (SATURDAY NIGHT THROUGH FRIDAY)... MEDIUM AND LONG TERM MODELS HAVE BEEN FAIRLY CONSISTENT THE LAST FEW DAYS...LATEST DAY 5 AND 6 VERIFICATION SCORES SHOW THE CANADIAN LEADING THE PACK THE LAST TWO DAYS WITH THE EURO AND GFS JUST BEHIND. GFS HAS BEEN SOLID THROUGH DAY 5...WILL FOLLOW THERE AND THEN LEAN TOWARDS THE EURO THROUGH THE REST OF THE PERIOD...IT HAS BEEN STABLE AND HAS MUCH SUPPORT FROM THE HIGH PERFORMING CANADIAN. SATURDAY NIGHT THROUGH MONDAY... UPPER LEVEL TROUGH ROTATING THROUGH THE FORECAST AREA SATURDAY NIGHT WILL CREATE SOME FORCING...ALONG WITH A MODEST AMOUNT OF MOISTURE THROUGH THE COLUMN...WILL ALLOW FOR CHANCE OF SNOW SHOWERS THROUGH THE NIGHT. LITTLE ACCUMULATION...BUT A SLIGHT WHITENING OF SURFACES LOOKS POSSIBLE. MUCH DRIER AIR STARTS TO ADVECT INTO THE OHIO VALLEY EARLY SUNDAY FROM THE WEST AS THE UPPER LEVEL TROUGH MOVES EAST OF THE APPALACHIANS. COLD DAY SUNDAY WITH THE COMBO OF H850 TEMPS NEAR -10C AND SOME LINGERING CLOUDS EARLY...BUT WILL GIVE FINALLY TO ALLOW FOR A MOSTLY SUNNY AFTERNOON. BOTH SATURDAY NIGHT AND SUNDAY MAY BE SOMEWHAT BREEZY WITH SOME GUSTS NEAR 25 MPH POSSIBLE. SLIGHT WAA DEVELOPS LATE SUNDAY AS SURFACE HI SHIFTS FROM THE SOUTHERN ROCKIES INTO THE WESTERN GULF STATES BRINGING WARMER AIR IN FROM THE PLAINS. H850 TEMPS CLIMB TO AROUND +2C BY MONDAY AFTERNOON AND NEAR FULL SUN...TEMPS WILL CLIMB BACK TO SEASONAL EARLY MARCH LEVELS. TUESDAY THROUGH FRIDAY AREA SANDWICHED BETWEEN THE RIDGING ACROSS THE WESTERN PLAINS AND THE NORTHEASTERN TROUGH...CREATING A WNW FLOW OVER THE OHIO VALLEY. TROUGH CONTINUES TO SLOWLY MOVE FURTHER EAST OFF THE COAST WITH INCREASING HEIGHTS OVER THE OHIO VALLEY INTO THURSDAY AS THE RIDGING FLATTENS AND DRIFTS EAST TOWARDS THE REGION. PATTERN BECOMES NEARLY ZONAL OVER THE ENTIRE CONUS BY FRIDAY. BACKDOOR COLD FRONT LOOKS TO PUSH INTO OR NEAR THE FORECAST AREA TUESDAY...AS LARGE SURFACE HIGH MOVES FROM JUST SOUTH OF HUDSON BAY INTO THE NORTHEAST BY WEDNESDAY MORNING. TEMPS MAY EB SLIGHTLY COOLER TUESDAY THAN MONDAY AS A FEW MORE CLOUDS AND SLIGHTLY COOLER AIR ALOFT WORKS INTO THE MID OHIO VALLEY. AS THE RIDGING MOVES MORE INTO THE AREA ALONG WITH A MORE SOUTHERLY FLOW WEDNESDAY INTO THURSDAY TEMPS LOOKS TO BE ABOVE NORMAL EACH DAY WITH PLENTY OF SUNSHINE. COLD FRONT LOOKS TO BE POISED TO DROP INTO THE FORECAST AREA ON FRIDAY...AS CLOUDS INCREASE EARLY. AREA OF LOW PRESSURE WILL DEVELOP ACROSS THE SOUTHERN PLAINS AND MOVE UP THROUGH THE REGION DURING THE DAY...WITH BEST PRECIP CHANCES LOOKING TO BE IN THE AFTN/EVEN. TEMPERATURES DO NOT LOOK AS COOL BEHIND THE FRONT AS THEY DID THE LAST FEW RUNS...WHICH GOES INLINE BETTER WITH THE LATEST INDICES(PNA/NAO/EPO). THEY CONTINUE TO INDICATE THE PERIOD THROUGH THE MIDDLE OF MONTH SHOULD FAVOR AT LEAST NORMAL TO SLIGHTLY ABOVE NORMAL. SCHOTT && .AVIATION (00Z TAFS)... IMPRESSIVE WINDS THIS AFTERNOON OVER THE ENTIRE CWA WITH GUSTS AS HIGH AS 46KTS AT KLEX AROUND 21Z. STEEP LAPSE RATES UP TO 600MB ON RECENT ACARS SOUNDINGS FROM KSDF...MORE REMINISCENT OF SOUNDINGS SEEN IN THE HIGH PLAINS DURING THE SUMMER. WINDS ARE FCST TO DROP OFF DRAMATICALLY BETWEEN 0Z-2Z THIS EVENING PER LATEST RUC. EVEN WITH SCT RADAR RETURNS...LITTLE IF ANY PRECIP FCST TO REACH THE SFC THIS EVENING GIVEN TEMP-DWPT SPREADS ON THE ORDER OF 35 DEGREES. THEY WOULD CERTAINLY NOT BE ENOUGH TO RESTRICT VSBYS AT TAF SITES...BUT ANY VIRGA WOULD BE CAPABLE OF PRODUCING LOCALIZED DOWNDRAFTS. VERY LATE TONIGHT...BUT MORE SO TOMORROW...CHCS FOR -SHRA ARE FCST...WITH A FEW -SHSN POSSIBLE AT SDF/LEX TERMINALS DURING THE AFTN AS BOUNDARY LAYER COOLS PER NAM FCST SOUNDINGS. WILL HANDLE WITH VCSH FOR TIME BEING DUE TO UNCERTAINTIES IN COVERAGE. CS && .LMK WATCHES/WARNINGS/ADVISORIES... KY...NONE. IN...NONE. && $$
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
655 PM EST FRI MAR 2 2007 .UPDATE... QUICK UPDATE TO EXPIRE THE WIND ADVISORY. WILL CONTINUE AN SPS THROUGH 9 PM EST TO ACCOUNT FOR GUSTS UP TO 25 OR 30 MPH. WINDS SHOULD SUBSIDE TO 5-15 MPH RANGE AFTERWARD. CS .AVIATION (00Z TAFS)... IMPRESSIVE WINDS THIS AFTERNOON OVER THE ENTIRE CWA WITH GUSTS AS HIGH AS 46KTS AT KLEX AROUND 21Z. STEEP LAPSE RATES UP TO 600MB ON RECENT ACARS SOUNDINGS FROM KSDF...MORE REMINISCENT OF SOUNDINGS SEEN IN THE HIGH PLAINS DURING THE SUMMER. WINDS ARE FCST TO DROP OFF DRAMATICALLY BETWEEN 0Z-2Z THIS EVENING PER LATEST RUC. EVEN WITH SCT RADAR RETURNS...LITTLE IF ANY PRECIP FCST TO REACH THE SFC THIS EVENING GIVEN TEMP-DWPT SPREADS ON THE ORDER OF 35 DEGREES. THEY WOULD CERTAINLY NOT BE ENOUGH TO RESTRICT VSBYS AT TAF SITES...BUT ANY VIRGA WOULD BE CAPABLE OF PRODUCING LOCALIZED DOWNDRAFTS. VERY LATE TONIGHT...BUT MORE SO TOMORROW...CHCS FOR -SHRA ARE FCST...WITH A FEW -SHSN POSSIBLE AT SDF/LEX TERMINALS DURING THE AFTN AS BOUNDARY LAYER COOLS PER NAM FCST SOUNDINGS. WILL HANDLE WITH VCSH FOR TIME BEING DUE TO UNCERTAINTIES IN COVERAGE. CS && .SHORT TERM (TONIGHT AND SATURDAY) SOME MAJOR PROBLEMS TO DEAL WITH IN THE SHORT TERM. FIRST AND FOREMOST IS THE STRONG AND GUSTY WINDS THIS AFTERNOON AND EVENING. A TIGHT PRESSURE GRADIENT AROUND THE DEEP GREAT LAKES LOW PRESSURE IS CAUSING WIND GUSTS FROM 40 TO 50 MPH AT TIMES ACROSS N CNTRL KY AND S CNTRL INDIANA THAT WILL DIMINISHING DURING THE EVENING HOURS. SO KEPT THE WIND ADVISORY ACROSS THE SAME AREA UNTIL 00Z TONIGHT. ON SATURDAY AS THE CLOSED 500 MB LOW OVER STARTS TO LIFT EAST NORTHEAST TOWARDS SOUTHERN CANADA...A RATHER VIGOROUS SHORT WAVE ROTATES AROUND THE SOUTH SIDE AROUND THIS CLOSED CIRCULATION AND BRINGS A BURST OF COLDER AIR THAT IS RELATIVELY MOIST IN THE LOWER LEVELS UP TO ABOUT THE 700 MB LEVEL. THERE IS ALSO SOME DECENT SYNOPTIC SCALE LIFT...SO THERE IS AT LEAST A CHANCE OF RAIN OR SNOW ON SATURDAY. WILL GO WITH 30 PERCENT NRN TWO THIRDS OF FA AND 20 PCT ACROSS THE SOUTH. WITH INCREASED CLOUDS AND PCPN THREAT ALONG WITH GOOD COLD AIR ADVECTION...WILL GO WITH MAX TEMPS A FEW DEGS BELOW THE MAV FCSTS FOR SATURDAY. THIS AGREES WELL WITH IND..ILN AND PAH FCSTS TOO. --21 .LONG TERM (SATURDAY NIGHT THROUGH FRIDAY)... MEDIUM AND LONG TERM MODELS HAVE BEEN FAIRLY CONSISTENT THE LAST FEW DAYS...LATEST DAY 5 AND 6 VERIFICATION SCORES SHOW THE CANADIAN LEADING THE PACK THE LAST TWO DAYS WITH THE EURO AND GFS JUST BEHIND. GFS HAS BEEN SOLID THROUGH DAY 5...WILL FOLLOW THERE AND THEN LEAN TOWARDS THE EURO THROUGH THE REST OF THE PERIOD...IT HAS BEEN STABLE AND HAS MUCH SUPPORT FROM THE HIGH PERFORMING CANADIAN. SATURDAY NIGHT THROUGH MONDAY... UPPER LEVEL TROUGH ROTATING THROUGH THE FORECAST AREA SATURDAY NIGHT WILL CREATE SOME FORCING...ALONG WITH A MODEST AMOUNT OF MOISTURE THROUGH THE COLUMN...WILL ALLOW FOR CHANCE OF SNOW SHOWERS THROUGH THE NIGHT. LITTLE ACCUMULATION...BUT A SLIGHT WHITENING OF SURFACES LOOKS POSSIBLE. MUCH DRIER AIR STARTS TO ADVECT INTO THE OHIO VALLEY EARLY SUNDAY FROM THE WEST AS THE UPPER LEVEL TROUGH MOVES EAST OF THE APPALACHIANS. COLD DAY SUNDAY WITH THE COMBO OF H850 TEMPS NEAR -10C AND SOME LINGERING CLOUDS EARLY...BUT WILL GIVE FINALLY TO ALLOW FOR A MOSTLY SUNNY AFTERNOON. BOTH SATURDAY NIGHT AND SUNDAY MAY BE SOMEWHAT BREEZY WITH SOME GUSTS NEAR 25 MPH POSSIBLE. SLIGHT WAA DEVELOPS LATE SUNDAY AS SURFACE HI SHIFTS FROM THE SOUTHERN ROCKIES INTO THE WESTERN GULF STATES BRINGING WARMER AIR IN FROM THE PLAINS. H850 TEMPS CLIMB TO AROUND +2C BY MONDAY AFTERNOON AND NEAR FULL SUN...TEMPS WILL CLIMB BACK TO SEASONAL EARLY MARCH LEVELS. TUESDAY THROUGH FRIDAY AREA SANDWICHED BETWEEN THE RIDGING ACROSS THE WESTERN PLAINS AND THE NORTHEASTERN TROUGH...CREATING A WNW FLOW OVER THE OHIO VALLEY. TROUGH CONTINUES TO SLOWLY MOVE FURTHER EAST OFF THE COAST WITH INCREASING HEIGHTS OVER THE OHIO VALLEY INTO THURSDAY AS THE RIDGING FLATTENS AND DRIFTS EAST TOWARDS THE REGION. PATTERN BECOMES NEARLY ZONAL OVER THE ENTIRE CONUS BY FRIDAY. BACKDOOR COLD FRONT LOOKS TO PUSH INTO OR NEAR THE FORECAST AREA TUESDAY...AS LARGE SURFACE HIGH MOVES FROM JUST SOUTH OF HUDSON BAY INTO THE NORTHEAST BY WEDNESDAY MORNING. TEMPS MAY EB SLIGHTLY COOLER TUESDAY THAN MONDAY AS A FEW MORE CLOUDS AND SLIGHTLY COOLER AIR ALOFT WORKS INTO THE MID OHIO VALLEY. AS THE RIDGING MOVES MORE INTO THE AREA ALONG WITH A MORE SOUTHERLY FLOW WEDNESDAY INTO THURSDAY TEMPS LOOKS TO BE ABOVE NORMAL EACH DAY WITH PLENTY OF SUNSHINE. COLD FRONT LOOKS TO BE POISED TO DROP INTO THE FORECAST AREA ON FRIDAY...AS CLOUDS INCREASE EARLY. AREA OF LOW PRESSURE WILL DEVELOP ACROSS THE SOUTHERN PLAINS AND MOVE UP THROUGH THE REGION DURING THE DAY...WITH BEST PRECIP CHANCES LOOKING TO BE IN THE AFTN/EVEN. TEMPERATURES DO NOT LOOK AS COOL BEHIND THE FRONT AS THEY DID THE LAST FEW RUNS...WHICH GOES INLINE BETTER WITH THE LATEST INDICES(PNA/NAO/EPO). THEY CONTINUE TO INDICATE THE PERIOD THROUGH THE MIDDLE OF MONTH SHOULD FAVOR AT LEAST NORMAL TO SLIGHTLY ABOVE NORMAL. SCHOTT && .LMK WATCHES/WARNINGS/ADVISORIES... KY...NONE. IN...NONE. && $$
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
615 PM EST FRI MAR 2 2007 .AVIATION (00Z TAFS)... IMPRESSIVE WINDS THIS AFTERNOON OVER THE ENTIRE CWA WITH GUSTS AS HIGH AS 46KTS AT KLEX AROUND 21Z. STEEP LAPSE RATES UP TO 600MB ON RECENT ACARS SOUNDINGS FROM KSDF...MORE REMINISCENT OF SOUNDINGS SEEN IN THE HIGH PLAINS DURING THE SUMMER. WINDS ARE FCST TO DROP OFF DRAMATICALLY BETWEEN 0Z-2Z THIS EVENING PER LATEST RUC. EVEN WITH SCT RADAR RETURNS...LITTLE IF ANY PRECIP FCST TO REACH THE SFC THIS EVENING GIVEN TEMP-DWPT SPREADS ON THE ORDER OF 35 DEGREES. THEY WOULD CERTAINLY NOT BE ENOUGH TO RESTRICT VSBYS AT TAF SITES...BUT ANY VIRGA WOULD BE CAPABLE OF PRODUCING LOCALIZED DOWNDRAFTS. VERY LATE TONIGHT...BUT MORE SO TOMORROW...CHCS FOR -SHRA ARE FCST...WITH A FEW -SHSN POSSIBLE AT SDF/LEX TERMINALS DURING THE AFTN AS BOUNDARY LAYER COOLS PER NAM FCST SOUNDINGS. WILL HANDLE WITH VCSH FOR TIME BEING DUE TO UNCERTAINTIES IN COVERAGE. CS && .SHORT TERM (TONIGHT AND SATURDAY) SOME MAJOR PROBLEMS TO DEAL WITH IN THE SHORT TERM. FIRST AND FOREMOST IS THE STRONG AND GUSTY WINDS THIS AFTERNOON AND EVENING. A TIGHT PRESSURE GRADIENT AROUND THE DEEP GREAT LAKES LOW PRESSURE IS CAUSING WIND GUSTS FROM 40 TO 50 MPH AT TIMES ACROSS N CNTRL KY AND S CNTRL INDIANA THAT WILL DIMINISHING DURING THE EVENING HOURS. SO KEPT THE WIND ADVISORY ACROSS THE SAME AREA UNTIL 00Z TONIGHT. ON SATURDAY AS THE CLOSED 500 MB LOW OVER STARTS TO LIFT EAST NORTHEAST TOWARDS SOUTHERN CANADA...A RATHER VIGOROUS SHORT WAVE ROTATES AROUND THE SOUTH SIDE AROUND THIS CLOSED CIRCULATION AND BRINGS A BURST OF COLDER AIR THAT IS RELATIVELY MOIST IN THE LOWER LEVELS UP TO ABOUT THE 700 MB LEVEL. THERE IS ALSO SOME DECENT SYNOPTIC SCALE LIFT...SO THERE IS AT LEAST A CHANCE OF RAIN OR SNOW ON SATURDAY. WILL GO WITH 30 PERCENT NRN TWO THIRDS OF FA AND 20 PCT ACROSS THE SOUTH. WITH INCREASED CLOUDS AND PCPN THREAT ALONG WITH GOOD COLD AIR ADVECTION...WILL GO WITH MAX TEMPS A FEW DEGS BELOW THE MAV FCSTS FOR SATURDAY. THIS AGREES WELL WITH IND..ILN AND PAH FCSTS TOO. --21 .LONG TERM (SATURDAY NIGHT THROUGH FRIDAY)... MEDIUM AND LONG TERM MODELS HAVE BEEN FAIRLY CONSISTENT THE LAST FEW DAYS...LATEST DAY 5 AND 6 VERIFICATION SCORES SHOW THE CANADIAN LEADING THE PACK THE LAST TWO DAYS WITH THE EURO AND GFS JUST BEHIND. GFS HAS BEEN SOLID THROUGH DAY 5...WILL FOLLOW THERE AND THEN LEAN TOWARDS THE EURO THROUGH THE REST OF THE PERIOD...IT HAS BEEN STABLE AND HAS MUCH SUPPORT FROM THE HIGH PERFORMING CANADIAN. SATURDAY NIGHT THROUGH MONDAY... UPPER LEVEL TROUGH ROTATING THROUGH THE FORECAST AREA SATURDAY NIGHT WILL CREATE SOME FORCING...ALONG WITH A MODEST AMOUNT OF MOISTURE THROUGH THE COLUMN...WILL ALLOW FOR CHANCE OF SNOW SHOWERS THROUGH THE NIGHT. LITTLE ACCUMULATION...BUT A SLIGHT WHITENING OF SURFACES LOOKS POSSIBLE. MUCH DRIER AIR STARTS TO ADVECT INTO THE OHIO VALLEY EARLY SUNDAY FROM THE WEST AS THE UPPER LEVEL TROUGH MOVES EAST OF THE APPALACHIANS. COLD DAY SUNDAY WITH THE COMBO OF H850 TEMPS NEAR -10C AND SOME LINGERING CLOUDS EARLY...BUT WILL GIVE FINALLY TO ALLOW FOR A MOSTLY SUNNY AFTERNOON. BOTH SATURDAY NIGHT AND SUNDAY MAY BE SOMEWHAT BREEZY WITH SOME GUSTS NEAR 25 MPH POSSIBLE. SLIGHT WAA DEVELOPS LATE SUNDAY AS SURFACE HI SHIFTS FROM THE SOUTHERN ROCKIES INTO THE WESTERN GULF STATES BRINGING WARMER AIR IN FROM THE PLAINS. H850 TEMPS CLIMB TO AROUND +2C BY MONDAY AFTERNOON AND NEAR FULL SUN...TEMPS WILL CLIMB BACK TO SEASONAL EARLY MARCH LEVELS. TUESDAY THROUGH FRIDAY AREA SANDWICHED BETWEEN THE RIDGING ACROSS THE WESTERN PLAINS AND THE NORTHEASTERN TROUGH...CREATING A WNW FLOW OVER THE OHIO VALLEY. TROUGH CONTINUES TO SLOWLY MOVE FURTHER EAST OFF THE COAST WITH INCREASING HEIGHTS OVER THE OHIO VALLEY INTO THURSDAY AS THE RIDGING FLATTENS AND DRIFTS EAST TOWARDS THE REGION. PATTERN BECOMES NEARLY ZONAL OVER THE ENTIRE CONUS BY FRIDAY. BACKDOOR COLD FRONT LOOKS TO PUSH INTO OR NEAR THE FORECAST AREA TUESDAY...AS LARGE SURFACE HIGH MOVES FROM JUST SOUTH OF HUDSON BAY INTO THE NORTHEAST BY WEDNESDAY MORNING. TEMPS MAY EB SLIGHTLY COOLER TUESDAY THAN MONDAY AS A FEW MORE CLOUDS AND SLIGHTLY COOLER AIR ALOFT WORKS INTO THE MID OHIO VALLEY. AS THE RIDGING MOVES MORE INTO THE AREA ALONG WITH A MORE SOUTHERLY FLOW WEDNESDAY INTO THURSDAY TEMPS LOOKS TO BE ABOVE NORMAL EACH DAY WITH PLENTY OF SUNSHINE. COLD FRONT LOOKS TO BE POISED TO DROP INTO THE FORECAST AREA ON FRIDAY...AS CLOUDS INCREASE EARLY. AREA OF LOW PRESSURE WILL DEVELOP ACROSS THE SOUTHERN PLAINS AND MOVE UP THROUGH THE REGION DURING THE DAY...WITH BEST PRECIP CHANCES LOOKING TO BE IN THE AFTN/EVEN. TEMPERATURES DO NOT LOOK AS COOL BEHIND THE FRONT AS THEY DID THE LAST FEW RUNS...WHICH GOES INLINE BETTER WITH THE LATEST INDICES(PNA/NAO/EPO). THEY CONTINUE TO INDICATE THE PERIOD THROUGH THE MIDDLE OF MONTH SHOULD FAVOR AT LEAST NORMAL TO SLIGHTLY ABOVE NORMAL. SCHOTT && .LMK WATCHES/WARNINGS/ADVISORIES... KY...WIND ADVISORY UNTIL 7 PM EST THIS EVENING FOR NORTH HALF OF CENTRAL KY. IN...WIND ADVISORY UNTIL 7 PM EST THIS EVENING FOR ALL OF SOUTH CENTRAL INDIANA. && $$
AREA FORECAST DISCUSSION
NWS JACKSON KY
659 AM EST THU MAR 1 2007 .SHORT TERM.../TODAY THROUGH FRIDAY NIGHT/ WEATHER REMINISCENT OF EARLY SPRING WINDING UP ACROSS THE MS RVR AND INTO THE OH/TN VALLEYS. FEW SVR STORMS ALREADY BEING REPORTED OVER WRN KY AND EXPECT THIS TO CONTINUE MOVING EAST TODAY. LOW LVL JET BETWEEN 925-850 MB WITH VAD WINDS OF 50-55 KTS. INVERSION HAS SO FAR KEPT THESE WINDS OFF THE SFC BUT WILL EXPECT MIXING WITH THE RISING SUN. NOSE OF 150+ KT JET TO ACCOMPANY STORMS INTO CNTRL/ERN KY SO UPPER DIVERGENCE TO ADD TO SVR PUNCH. NAM BUFR INDICATING GOOD UNI- DIRECTIONAL SHEAR... INDICATING DAMAGING WINDS AND HAIL TO BE THE GREATEST THREATS. HOWEVER CAPE NOT IMPRESSIVE AND BEST INSTABILITY LOOKS TO BE ELEVATED BUT FNTL DYNAMICS MAY OVERCOME THIS LACK. MOST PCPN TO CLEAR THE STATE BY 06Z WITH COOLER BY NOT YET COLD AIR AS WEST WINDS BEHIND THE FNT DO NOT TAP THE COLDER AIR OVER THE NRN PLAINS. .LONG TERM.../SATURDAY THROUGH WEDNESDAY/ SAT TO SEE VERY LITTLE DIURNAL TEMP RISE AS LOW TRACKS UP THE ST LAWRENCE AND WINDS SHIFT TO NW. STILL A DRY FCST EXCEPT THAT THE LOW LVLWINDS WILL TAP LK MI TO BRING CHC OF LK EFFECT/UPSLOPE FLURRIES TO OUR CWFA. ANY PCPN WILL BE VERY LIGHT AND LITTLE SNOW ACCUM EXPECTED. HIGH PRESS TO BUILD INTO THE GULF STATES KEEPING ANY STORM TRACK TO OUR NORTH AND PROVIDING AT BEST ONLY A GLANCING BLOW TO OUR AREA WITH THE BULK OF WEATHER CONFINED TO SRN CANADA AND THE NRN GT LKS. && .AVIATION.../12Z TO 12Z/...UPDATED WILL CONTINUE TO CARRY LLWS AS OBS ARE CARRYING LIGHT WINDS AT THE SFC WHILE THE JKL 88D VAD WIND PROFILER IS SHOWING A STRONG WINDS INCREASING OUT OF THE SOUTH AT 40 TO 50+ KTS JUST 1KFT OFF THE SFC. ALSO HAD A PIREP FROM AN AIRCRAFT TAKING OFF FROM SDF WITH A LLWS OF -15KT DURING TAKEOFF. WIND SHEAR WILL CONTINUE...AND SOME OF THE STRONGER WINDS SHOULD BEGIN TO MIX DOWN TO THE SURFACE AFTER SUNRISE. WILL CARRY GUSTS TO BETWEEN 25 AND 30 KT AT ALL TERMINALS THROUGH THE DAY AS WE TAP INTO A STRONG 65 TO 75 KT SOUTHERLY JET THAT WILL DEVELOP JUST A FEW THOUSAND FT OFF THE GROUND. OTHERWISE...GULF MOISTURE WILL CONTINUE TO STREAM INTO THE AREA. SHOWERS AND THUNDERSTORMS HAVE ALREADY ENTERED INTO THE SME AND LOZ AREAS. HOWEVER...THERE IS A NOTICEABLE WEAKENING TREND AS THUNDERSTORMS PUSH INTO LESS FAVORABLE ENVIRONMENT IN THE INTERMOUNTAIN PORTIONS OF EASTERN KENTUCKY. SUSPECT THAT SE DOWNSLOPE COMPONENT PROBABLY PLAYING A ROLE IN HELPING TO RETARD OVERALL INSTABILITY ACROSS THE AREA. THUNDERSTORMS WILL EVENTUALLY REACH FURTHER EAST LATER TODAY. BASED ON FCST SOUNDINGS AND UPSTREAM OBS...TRENDED TOWARDS LOWER MVFR CIGS AS THE DAY PROGRESSES. VISBY WILL REACH IFR LEVELS LATER THIS EVENING WITH MORE INTENSE THUNDERSTORMS. APPEARS THAT THE COLD FRONT WILL MOVE THROUGH THE TAF SITES BETWEEN 9 PM AND MIDNIGHT THURSDAY. THE MAIN THREAT FOR SEVERE WEATHER IN OUR AREA BE IN A WINDOW ROUGHLY FROM 4 PM TO MIDNIGHT. && .JKL WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SHORT TERM...DUSTY LONG TERM....DUSTY AVIATION...RAY
AREA FORECAST DISCUSSION
NWS BALTIMORE MD/WASHINGTON DC
949 PM EST FRI MAR 2 2007 .SHORT TERM UPDATE /REST OF TONIGHT AND SATURDAY/... INFRARED IMAGERY INDICATES A COUPLE OF AREA OF CLOUDINESS NEAR US THIS EVENING...ONE TO OUR SOUTH IN THE CAROLINAS ASSOCIATED WITH A POWERFUL 170 KT UPPER JET...AND ANOTHER ALONG AND WEST OF THE MTNS BEING SUPPORTED BY MID LEVEL POSITIVE VORTICITY ADVECTION. REGIONAL RADARS ALSO SHOW SOME LIGHT PRECIPITATION ACROSS PORTIONS OF CENTRAL PA...FAR WESTERN MD AND THE STATE OF WV. NAM AND GFS ARE IN GOOD AGREEMENT CURVING THE UPPER JET FURTHER NORTH TONIGHT...ALLOWING SOME OF THE HIGH LEVEL CLOUDINESS TO SNEAK INTO OUR SOUTHERN CWA. IN ADDITION...MID LEVEL CLOUDINESS WILL ADVECT TOWARD THE EAST...SO WILL TRANSITION THE GENERALLY CLEAR SKY THIS EVENING TO A PARTLY CLOUDY ONE AFTER MIDNIGHT. GIVEN ACTIVITY ON RADAR...INCREASING PVA AND STEEPENING LAPSE RATES...WILL ALLOW FOR SHOWERS (RAIN OR SNOW) WEST OF THE BLUE RIDGE OVERNIGHT...HIGHEST POPS AROUND 40 ALONG OUR WESTERN BORDER. DO NOT EXPECT SHOWERS TO CROSS THE BLUE RIDGE OVERNIGHT... ...HOWEVER DO EXPECT SOME SHOWERS TO BECOME PREVALENT EAST OF THE MTNS ON SATURDAY...ESPECIALLY DURING THE AFTERNOON DUE TO A COMBINATION OF INSTABILITY AND PVA THAT WILL PARTNER WITH A COLD FRONT. CONFIDENCE OF THUNDER CONTINUES TO BE LOW...SO HAVE NOT INTRODUCED A MENTION OF THUNDER ATTM. IF ANY THUNDER DEVELOPS...FORECAST BUFKIT SOUNDINGS FROM THE NAM AND GFS INDICATE THAT GUSTY WINDS AND SMALL HAIL WILL BE POSSIBLE. EVEN OUTSIDE OF THUNDER...SHOWERS THEMSELVES WILL BE CAPABLE OF TRANSFERRING GUSTIER WINDS TO THE SURFACE. && .AVIATION /02Z-24Z/... VFR CONDITIONS EXPECTED TO PREVAIL THROUGH 24Z. INSTABILITY SHOWERS MAY OCCUR SATURDAY AFTERNOON...AND COULD RESTRICT CIGS AND/OR VSBYS INTO MVFR AND BRING GUSTY WINDS. GIVEN LOW CONFIDENCE OF LOCATION OF SHOWERS THIS FAR OUT...HAVE NOT EXPLICITLY INCLUDED IN TAFS ATTM. && .MARINE... SW WINDS ABOUT 10 KT EXPECTED OVERNIGHT...INCREASING INTO SMALL CRAFT CRITERIA ON SATURDAY. SMALL CRAFT ADVISORY REMAINS IN EFFECT SATURDAY AND SATURDAY NIGHT. && .PREV DISCUSSION... /ISSUED 607 PM EST FRI MAR 2 2007/ MARINE UPDATE... HAVE ALLOWED THE SMALL CRAFT HEADLINE ON THE WATERS TO EXPIRE AT 6 PM. SENORS OVER AND NEAR THE WATERS HAVE SHOWN A DIMINISHING OF GUSTS THE PAST COUPLE OF HOURS...BELOW SMALL CRAFT CRITERIA. PREV DISCUSSION... /ISSUED 304 PM EST FRI MAR 2 2007/ SHORT TERM /TONIGHT THROUGH SATURDAY/... WATER VAPOR LOOP SHOWS AN UPPER LOW SPINNING OVER THE MIDWEST...WITH A DRY INTRUSION PROGRESSING NORTHEAST THROUGH THE APPALACHIANS AND EASTERN GREAT LAKES. ACARS 400-250MB WIND OBSERVATIONS REVEAL A 150-190KT WESTERLY JET ACROSS THE SOUTHERN CONUS...WHICH CURLS NORTHEAST THROUGH THE MID ATLANTIC. 11Z SURFACE ANALYSIS PLACED A 979MB OCCLUDED CYCLONE ACROSS CENTRAL WISCONSIN. THE OCCLUDED/COLD FRONT EXTENDED FROM THE CYCLONE EAST ACROSS THE EASTERN GREAT LAKES...THEN SOUTH THROUGH THE EASTERN PORTION OF THE CAROLINAS AND SOUTHWEST INTO THE CENTRAL GULF OF MEXICO. A WARM FRONT EXTENDED NORTHEAST FROM MANASSAS TOWARD LONG ISLAND. SEVERAL SECONDARY COLD FRONTS STRETCH SOUTHWEST AND WEST FROM THE OCCLUDED CYCLONE ACROSS THE CENTRAL CONUS. A TROUGH WAS NOTED IN THE LEE OF THE APPALACHIANS. WITH CLEAR SKIES AND DRYING BOUNDARY LAYER...DECOUPLING SHOULD OCCUR THIS EVENING. THE OPENING UP OF THE GREAT LAKES UPPER LOW WILL ALLOW STEEPER LAPSE RATES TO MOVE DOWNSTREAM INTO THE MID ATLANTIC REGION. EXPECT CLOUDS TO INVADE FROM THE NORTHWEST LATE TONIGHT AS A RESULT. CANT RULE OUT LIGHT SNOW SHOWERS ACROSS THE MOUNTAINS AS LAPSE RATES STEEPEN. LAPSE RATES CONTINUE TO STEEPEN THROUGHOUT THE DAY SATURDAY. THE SECONDARY COLD FRONT SHOULD BE MOVING THROUGH THE FORECAST AREA DURING AFTERNOON AND EVENING...COINCIDENT WITH THE TROUGH ALOFT. THIS SHOULD BE ENOUGH TO ENCOURAGE THE FORMATION OF SCATTERED SHOWERS. IF THEY DO DEVELOP...THE SHOWERS WILL HAVE HIGH BASES...WITH AN INVERTED-V SOUNDING DISPLAYED BY BOTH 12Z NAM/GFS BUFKIT FORECAST SOUNDINGS. EVAPORATIVE COOLING EFFECTS COULD LEAD TO LOCALLY HIGHER WIND GUSTS WITHIN RAIN SHOWERS. SNOW SHOWERS WILL BECOME MORE PREVALENT AND BEGIN TO INCREASE IN INTENSITY ACROSS THE MOUNTAINS WITH THE PASSAGE OF THE SECONDARY COLD FRONT DURING THE AFTERNOON. LONG TERM /SATURDAY NIGHT THROUGH FRIDAY/... THE LONG RANGE FORECAST WILL BE FAIRLY QUIET...WITH TWO MINOR SYSTEMS EXPECTED TO IMPACT THE FORECAST AREA ON SATURDAY NIGHT AND A SECOND STRONGER SYSTEM BY THE END OF NEXT WEEK. THE 500MB PATTERN IS STILL QUITE ACTIVE AT THE BEGINNING OF THE LONG TERM. A STRONG SHORTWAVE IS DIGGING SOUTH OVER TEXAS...WITH A LONGWAVE TROUGH ALONG THE EASTERN SEABOARD. THE SHORTWAVE ENERGY MOVES EAST OVER THE GULF STATES THROUGH SUNDAY NIGHT AND INTO THE ATLANTIC ALONG WITH THE LONGWAVE TROUGH. NORTHWEST FLOW ALOFT WILL PERSIST THROUGH MIDWEEK. THE FLOW BEGINS TO TURN MORE ZONAL IN NATURE AS AN UPPER LOW AND ASSOCIATED SHORTWAVE MOVE EAST OVER THE GULF STATES JUST AHEAD OF A DIGGING TROUGH OVER THE ROCKIES. THE GULF STATES UPPER LOW/SHORTWAVE IS EXPECTED TO STAY SOUTH OF THE CWFA...AND THE TROUGH OVER THE ROCKIES WILL MOVE INTO THE MID MISSISSIPPI VALLEY ON FRIDAY. A WEAK REINFORCING FRONTAL BOUNDARY WILL BE MAKING ITS WAY EAST OVER THE CWFA SATURDAY NIGHT. THE MAIN CHANGE TO THE GRIDS HERE WILL BE TO CHANGE THE PTYPE TO ALL SNOW. THE 850MB AND SURFACE TEMPERATURES WILL BE COLD ENOUGH FOR SNOW. THE GFS IS NOT PRODUCING MUCH QPF WITH THIS SYSTEM EAST OF THE ALLEGANY FRONT. THE FRONT SHOULD BE EAST OF THE CWFA BY EARLY SUNDAY WITH UPSLOPE SNOW SHOWERS CONTINUING THROUGH LATE SUNDAY. A SECOND WEAK FRONTAL BOUNDARY IS LIKELY ON TUESDAY...BUT LOOKS LIKE A DRY FROPA. WEDNESDAY AND THURSDAY LOOK DRY AS HIGH PRESSURE BUILDS OVER THE AREA. THE NEXT SYSTEM IS ON TRACK FOR THE FRIDAY/SATURDAY TIME FRAME. AVIATION... WINDS EXPECTED TO DECOUPLE WITH SUNSET. EXPECT LOW TO MID LEVEL CLOUDS TO SPREAD ACROSS THE REGION FROM THE NORTHWEST LATE TONIGHT AS LAPSE RATES STEEPEN WITH THE APPROACH OF A MID LEVEL TROUGH. EXPECT WINDS TO VEER AND BEGIN TO GUST DURING THE AFTERNOON. MARINE... 12Z ETA/GFS MOS AT THOMAS POINT INDICATE SUSTAINED WINDS WILL FALL TO 10KT TONIGHT...AND RISE BACK INTO THE 15-20KT RANGE TOMORROW AFTERNOON. 12Z NAM/GFS PROXIMITY FORECAST SOUNDINGS INDICATE WIND GUST POTENTIAL OF 30-35 KNOTS TOMORROW AFTERNOON. WILL RAISE A SMALL CRAFT COINCIDENT WITH THE APPROACH OF THE SECONDARY COLD FRONT. RAIN SHOWERS TOMORROW AFTERNOON MAY CONTAIN LOCALLY HIGHER WIND GUSTS. MARINERS SHOULD MONITOR FOR LATER FORECASTS. WIND SHOULD PICK UP BEHIND THE FRONTAL PASSAGE ON SUNDAY OVER THE MARINE WATERS. SMALL CRAFT CONDITIONS ARE LIKELY. && .LWX WATCHES/WARNINGS/ADVISORIES... DC...NONE. MD...NONE. VA...NONE. WV...NONE. MARINE...SMALL CRAFT ADVISORY FROM 10 AM SATURDAY TO 5 AM EST SUNDAY FOR ANZ530>537. && $$ SHORT TERM UPDATE/AVIATION/MARINE...B.PELOQUIN PREV DISCUSSION...ROGOWSKI/N.LISTEMAA
AREA FORECAST DISCUSSION
NWS BALTIMORE MD/WASHINGTON DC
607 PM EST FRI MAR 2 2007 .MARINE UPDATE... HAVE ALLOWED THE SMALL CRAFT HEADLINE ON THE WATERS TO EXPIRE AT 6 PM. SENORS OVER AND NEAR THE WATERS HAVE SHOWN A DIMINISHING OF GUSTS THE PAST COUPLE OF HOURS...BELOW SMALL CRAFT CRITERIA. && .PREV DISCUSSION... /ISSUED 304 PM EST FRI MAR 2 2007/ SHORT TERM /TONIGHT THROUGH SATURDAY/... WATER VAPOR LOOP SHOWS AN UPPER LOW SPINNING OVER THE MIDWEST...WITH A DRY INTRUSION PROGRESSING NORTHEAST THROUGH THE APPALACHIANS AND EASTERN GREAT LAKES. ACARS 400-250MB WIND OBSERVATIONS REVEAL A 150-190KT WESTERLY JET ACROSS THE SOUTHERN CONUS...WHICH CURLS NORTHEAST THROUGH THE MID ATLANTIC. 11Z SURFACE ANALYSIS PLACED A 979MB OCCLUDED CYCLONE ACROSS CENTRAL WISCONSIN. THE OCCLUDED/COLD FRONT EXTENDED FROM THE CYCLONE EAST ACROSS THE EASTERN GREAT LAKES...THEN SOUTH THROUGH THE EASTERN PORTION OF THE CAROLINAS AND SOUTHWEST INTO THE CENTRAL GULF OF MEXICO. A WARM FRONT EXTENDED NORTHEAST FROM MANASSAS TOWARD LONG ISLAND. SEVERAL SECONDARY COLD FRONTS STRETCH SOUTHWEST AND WEST FROM THE OCCLUDED CYCLONE ACROSS THE CENTRAL CONUS. A TROUGH WAS NOTED IN THE LEE OF THE APPALACHIANS. WITH CLEAR SKIES AND DRYING BOUNDARY LAYER...DECOUPLING SHOULD OCCUR THIS EVENING. THE OPENING UP OF THE GREAT LAKES UPPER LOW WILL ALLOW STEEPER LAPSE RATES TO MOVE DOWNSTREAM INTO THE MID ATLANTIC REGION. EXPECT CLOUDS TO INVADE FROM THE NORTHWEST LATE TONIGHT AS A RESULT. CANT RULE OUT LIGHT SNOW SHOWERS ACROSS THE MOUNTAINS AS LAPSE RATES STEEPEN. LAPSE RATES CONTINUE TO STEEPEN THROUGHOUT THE DAY SATURDAY. THE SECONDARY COLD FRONT SHOULD BE MOVING THROUGH THE FORECAST AREA DURING AFTERNOON AND EVENING...COINCIDENT WITH THE TROUGH ALOFT. THIS SHOULD BE ENOUGH TO ENCOURAGE THE FORMATION OF SCATTERED SHOWERS. IF THEY DO DEVELOP...THE SHOWERS WILL HAVE HIGH BASES...WITH AN INVERTED-V SOUNDING DISPLAYED BY BOTH 12Z NAM/GFS BUFKIT FORECAST SOUNDINGS. EVAPORATIVE COOLING EFFECTS COULD LEAD TO LOCALLY HIGHER WIND GUSTS WITHIN RAIN SHOWERS. SNOW SHOWERS WILL BECOME MORE PREVALENT AND BEGIN TO INCREASE IN INTENSITY ACROSS THE MOUNTAINS WITH THE PASSAGE OF THE SECONDARY COLD FRONT DURING THE AFTERNOON. LONG TERM /SATURDAY NIGHT THROUGH FRIDAY/... THE LONG RANGE FORECAST WILL BE FAIRLY QUIET...WITH TWO MINOR SYSTEMS EXPECTED TO IMPACT THE FORECAST AREA ON SATURDAY NIGHT AND A SECOND STRONGER SYSTEM BY THE END OF NEXT WEEK. THE 500MB PATTERN IS STILL QUITE ACTIVE AT THE BEGINNING OF THE LONG TERM. A STRONG SHORTWAVE IS DIGGING SOUTH OVER TEXAS...WITH A LONGWAVE TROUGH ALONG THE EASTERN SEABOARD. THE SHORTWAVE ENERGY MOVES EAST OVER THE GULF STATES THROUGH SUNDAY NIGHT AND INTO THE ATLANTIC ALONG WITH THE LONGWAVE TROUGH. NORTHWEST FLOW ALOFT WILL PERSIST THROUGH MIDWEEK. THE FLOW BEGINS TO TURN MORE ZONAL IN NATURE AS AN UPPER LOW AND ASSOCIATED SHORTWAVE MOVE EAST OVER THE GULF STATES JUST AHEAD OF A DIGGING TROUGH OVER THE ROCKIES. THE GULF STATES UPPER LOW/SHORTWAVE IS EXPECTED TO STAY SOUTH OF THE CWFA...AND THE TROUGH OVER THE ROCKIES WILL MOVE INTO THE MID MISSISSIPPI VALLEY ON FRIDAY. A WEAK REINFORCING FRONTAL BOUNDARY WILL BE MAKING ITS WAY EAST OVER THE CWFA SATURDAY NIGHT. THE MAIN CHANGE TO THE GRIDS HERE WILL BE TO CHANGE THE PTYPE TO ALL SNOW. THE 850MB AND SURFACE TEMPERATURES WILL BE COLD ENOUGH FOR SNOW. THE GFS IS NOT PRODUCING MUCH QPF WITH THIS SYSTEM EAST OF THE ALLEGANY FRONT. THE FRONT SHOULD BE EAST OF THE CWFA BY EARLY SUNDAY WITH UPSLOPE SNOW SHOWERS CONTINUING THROUGH LATE SUNDAY. A SECOND WEAK FRONTAL BOUNDARY IS LIKELY ON TUESDAY...BUT LOOKS LIKE A DRY FROPA. WEDNESDAY AND THURSDAY LOOK DRY AS HIGH PRESSURE BUILDS OVER THE AREA. THE NEXT SYSTEM IS ON TRACK FOR THE FRIDAY/SATURDAY TIME FRAME. AVIATION... WINDS EXPECTED TO DECOUPLE WITH SUNSET. EXPECT LOW TO MID LEVEL CLOUDS TO SPREAD ACROSS THE REGION FROM THE NORTHWEST LATE TONIGHT AS LAPSE RATES STEEPEN WITH THE APPROACH OF A MID LEVEL TROUGH. EXPECT WINDS TO VEER AND BEGIN TO GUST DURING THE AFTERNOON. MARINE... 12Z ETA/GFS MOS AT THOMAS POINT INDICATE SUSTAINED WINDS WILL FALL TO 10KT TONIGHT...AND RISE BACK INTO THE 15-20KT RANGE TOMORROW AFTERNOON. 12Z NAM/GFS PROXIMITY FORECAST SOUNDINGS INDICATE WIND GUST POTENTIAL OF 30-35 KNOTS TOMORROW AFTERNOON. WILL RAISE A SMALL CRAFT COINCIDENT WITH THE APPROACH OF THE SECONDARY COLD FRONT. RAIN SHOWERS TOMORROW AFTERNOON MAY CONTAIN LOCALLY HIGHER WIND GUSTS. MARINERS SHOULD MONITOR FOR LATER FORECASTS. WIND SHOULD PICK UP BEHIND THE FRONTAL PASSAGE ON SUNDAY OVER THE MARINE WATERS. SMALL CRAFT CONDITIONS ARE LIKELY. && .LWX WATCHES/WARNINGS/ADVISORIES... DC...NONE. MD...NONE. VA...NONE. WV...NONE. MARINE...SMALL CRAFT ADVISORY FROM 10 AM SATURDAY TO 5 AM EST SUNDAY FOR ANZ530>537. && $$ MARINE UPDATE...B.PELOQUIN PREV DISCUSSION...ROGOWSKI/N.LISTEMAA
AREA FORECAST DISCUSSION
NWS BALTIMORE MD/WASHINGTON DC
304 PM EST FRI MAR 2 2007 .SHORT TERM /TONIGHT THROUGH SATURDAY/... WATER VAPOR LOOP SHOWS AN UPPER LOW SPINNING OVER THE MIDWEST...WITH A DRY INTRUSION PROGRESSING NORTHEAST THROUGH THE APPALACHIANS AND EASTERN GREAT LAKES. ACARS 400-250MB WIND OBSERVATIONS REVEAL A 150-190KT WESTERLY JET ACROSS THE SOUTHERN CONUS...WHICH CURLS NORTHEAST THROUGH THE MID ATLANTIC. 11Z SURFACE ANALYSIS PLACED A 979MB OCCLUDED CYCLONE ACROSS CENTRAL WISCONSIN. THE OCCLUDED/COLD FRONT EXTENDED FROM THE CYCLONE EAST ACROSS THE EASTERN GREAT LAKES...THEN SOUTH THROUGH THE EASTERN PORTION OF THE CAROLINAS AND SOUTHWEST INTO THE CENTRAL GULF OF MEXICO. A WARM FRONT EXTENDED NORTHEAST FROM MANASSAS TOWARD LONG ISLAND. SEVERAL SECONDARY COLD FRONTS STRETCH SOUTHWEST AND WEST FROM THE OCCLUDED CYCLONE ACROSS THE CENTRAL CONUS. A TROUGH WAS NOTED IN THE LEE OF THE APPALACHIANS. WITH CLEAR SKIES AND DRYING BOUNDARY LAYER...DECOUPLING SHOULD OCCUR THIS EVENING. THE OPENING UP OF THE GREAT LAKES UPPER LOW WILL ALLOW STEEPER LAPSE RATES TO MOVE DOWNSTREAM INTO THE MID ATLANTIC REGION. EXPECT CLOUDS TO INVADE FROM THE NORTHWEST LATE TONIGHT AS A RESULT. CANT RULE OUT LIGHT SNOW SHOWERS ACROSS THE MOUNTAINS AS LAPSE RATES STEEPEN. LAPSE RATES CONTINUE TO STEEPEN THROUGHOUT THE DAY SATURDAY. THE SECONDARY COLD FRONT SHOULD BE MOVING THROUGH THE FORECAST AREA DURING AFTERNOON AND EVENING...COINCIDENT WITH THE TROUGH ALOFT. THIS SHOULD BE ENOUGH TO ENCOURAGE THE FORMATION OF SCATTERED SHOWERS. IF THEY DO DEVELOP...THE SHOWERS WILL HAVE HIGH BASES...WITH AN INVERTED-V SOUNDING DISPLAYED BY BOTH 12Z NAM/GFS BUFKIT FORECAST SOUNDINGS. EVAPORATIVE COOLING EFFECTS COULD LEAD TO LOCALLY HIGHER WIND GUSTS WITHIN RAIN SHOWERS. SNOW SHOWERS WILL BECOME MORE PREVALENT AND BEGIN TO INCREASE IN INTENSITY ACROSS THE MOUNTAINS WITH THE PASSAGE OF THE SECONDARY COLD FRONT DURING THE AFTERNOON. && .LONG TERM /SATURDAY NIGHT THROUGH FRIDAY/... THE LONG RANGE FORECAST WILL BE FAIRLY QUIET...WITH TWO MINOR SYSTEMS EXPECTED TO IMPACT THE FORECAST AREA ON SATURDAY NIGHT AND A SECOND STRONGER SYSTEM BY THE END OF NEXT WEEK. THE 500MB PATTERN IS STILL QUITE ACTIVE AT THE BEGINNING OF THE LONG TERM. A STRONG SHORTWAVE IS DIGGING SOUTH OVER TEXAS...WITH A LONGWAVE TROUGH ALONG THE EASTERN SEABOARD. THE SHORTWAVE ENERGY MOVES EAST OVER THE GULF STATES THROUGH SUNDAY NIGHT AND INTO THE ATLANTIC ALONG WITH THE LONGWAVE TROUGH. NORTHWEST FLOW ALOFT WILL PERSIST THROUGH MIDWEEK. THE FLOW BEGINS TO TURN MORE ZONAL IN NATURE AS AN UPPER LOW AND ASSOCIATED SHORTWAVE MOVE EAST OVER THE GULF STATES JUST AHEAD OF A DIGGING TROUGH OVER THE ROCKIES. THE GULF STATES UPPER LOW/SHORTWAVE IS EXPECTED TO STAY SOUTH OF THE CWFA...AND THE TROUGH OVER THE ROCKIES WILL MOVE INTO THE MID MISSISSIPPI VALLEY ON FRIDAY. A WEAK REINFORCING FRONTAL BOUNDARY WILL BE MAKING ITS WAY EAST OVER THE CWFA SATURDAY NIGHT. THE MAIN CHANGE TO THE GRIDS HERE WILL BE TO CHANGE THE PTYPE TO ALL SNOW. THE 850MB AND SURFACE TEMPERATURES WILL BE COLD ENOUGH FOR SNOW. THE GFS IS NOT PRODUCING MUCH QPF WITH THIS SYSTEM EAST OF THE ALLEGANY FRONT. THE FRONT SHOULD BE EAST OF THE CWFA BY EARLY SUNDAY WITH UPSLOPE SNOW SHOWERS CONTINUING THROUGH LATE SUNDAY. A SECOND WEAK FRONTAL BOUNDARY IS LIKELY ON TUESDAY...BUT LOOKS LIKE A DRY FROPA. WEDNESDAY AND THURSDAY LOOK DRY AS HIGH PRESSURE BUILDS OVER THE AREA. THE NEXT SYSTEM IS ON TRACK FOR THE FRIDAY/SATURDAY TIME FRAME. && .AVIATION... WINDS EXPECTED TO DECOUPLE WITH SUNSET. EXPECT LOW TO MID LEVEL CLOUDS TO SPREAD ACROSS THE REGION FROM THE NORTHWEST LATE TONIGHT AS LAPSE RATES STEEPEN WITH THE APPROACH OF A MID LEVEL TROUGH. EXPECT WINDS TO VEER AND BEGIN TO GUST DURING THE AFTERNOON. && .MARINE... 12Z ETA/GFS MOS AT THOMAS POINT INDICATE SUSTAINED WINDS WILL FALL TO 10KT TONIGHT...AND RISE BACK INTO THE 15-20KT RANGE TOMORROW AFTERNOON. 12Z NAM/GFS PROXIMITY FORECAST SOUNDINGS INDICATE WIND GUST POTENTIAL OF 30-35 KNOTS TOMORROW AFTERNOON. WILL RAISE A SMALL CRAFT COINCIDENT WITH THE APPROACH OF THE SECONDARY COLD FRONT. RAIN SHOWERS TOMORROW AFTERNOON MAY CONTAIN LOCALLY HIGHER WIND GUSTS. MARINERS SHOULD MONITOR FOR LATER FORECASTS. WIND SHOULD PICK UP BEHIND THE FRONTAL PASSAGE ON SUNDAY OVER THE MARINE WATERS. SMALL CRAFT CONDITIONS ARE LIKELY. && .LWX WATCHES/WARNINGS/ADVISORIES... DC...NONE. MD...NONE. VA...NONE. WV...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EST THIS AFTERNOON FOR ANZ530>537. SMALL CRAFT ADVISORY FROM 10 AM TO 6 PM EST SATURDAY FOR ANZ530>537. && $$ SHORT TERM/AVIATION...ROGOWSKI LONG TERM...N.LISTEMAA MARINE...ROGOWSKI/N.LISTEMAA
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
525 AM EST THU MAR 1 2007 .DISCUSSION... UPPER AIR PATTERN CONSISTS OF A DEEP 500 MB TROUGH ACROSS THE WESTERN HALF OF THE U.S. WITH NUMEROUS SHORTWAVES EMBEDDED IN THIS TROUGH. ONE STRONG SHORTWAVE IS IN NORTHERN NEW MEXICO ON ONE OVER B.C. THE SOUTHERN SHORTWAVE WILL SERVE TO KICK THE TROUGH EAST AND ALLOW A NEGATIVE TILTED SHORTWAVE AND TROUGH TO DEVELOP THIS MORNING AS A SHORTWAVE ALONG THE MT/ND/SASKATCHEWAN BORDER HEADS SOUTHEAST AND HELPS TO STRENGTHEN THE CLOSED 500 MB LOW THAT WILL BE OVER CENTRAL IA BY 00Z TONIGHT ACCORDING TO THE NAM. NAM TAKES THE 500 MB LOW FROM CENTRAL IA 00Z TONIGHT TO NEAR KDBQ AT 12Z FRI AND THEN TO LOWER MI 00Z SAT AND TO CENTRAL LAKE HURON 12Z SAT. NAM TAKES THE 990 MB SFC LOW FROM NORTHERN OK THIS MORNING TO NEAR KDBQ 00Z FRI AT 980MB TO EAST OF KMSN 00Z SAT 989 MB. THE DEEPEST THE NAM HAS THIS LOW GET IS 978 MB SOUTH OF KLSE 06Z TONIGHT. THIS WOULD STILL BE A GOOD TRACK FOR HEAVY SNOWFALL FOR THE U.P. NAM SHOWING STRONG 850-500 MB Q-VECTOR CONVERGENCE MOVING INTO THE CWA TODAY AND THIS REMAINS UNTIL FRI AFTERNOON AS THE SYSTEM STARTS TO WEAKEN AND IS REPLACED BY Q-VECTOR DIVERGENCE 18Z FRI WHICH REMAINS THROUGH SAT. NAM ALSO SHOWING DRY AIR ON ISENTROPIC SURFACES FROM I280K-I295K WITH EASTERLY FLOW REMAINING OVER THE ERN HALF OF THE CWA THROUGH 00Z TONIGHT WITH STRONG LIFT OCCURRING OVER THE AREA. THIS DRY AIR WILL CONTINUE TO PLAY HAVOC WITH THIS FORECAST AS THIS WILL DICTATE WHEN PCPN WILL START AND KSAW TAMDAR SOUNDINGS SHOW DRY AIR ABOVE 800 MB WHICH NEEDS TO BE OVERCOME FIRST. 00Z KGRB SOUNDING SHOWS THIS AS WELL. PROBLEM SEEMS THOUGH THAT WHEN STRONG LIFT IS IN THE AREA WHICH NAM SHOWS TODAY...DRY AIR SEEMS TO ERODE AWAY QUICKER THAN WHAT GUIDANCE SHOWS AND AM CONCERNED THIS WILL HAPPEN. JUST LIKE THE LAST SYSTEM...THIS ONE WILL HAVE A STRONG PCPN GRADIENT AND TRYING TO FIGURE OUT WHERE THIS SETS UP WILL BE TOUGH. NAM SHOWS THIS DRY AIR OVER THE ERN CWA BEING ERODED BY 06Z TONIGHT ISENTROPIC LIFT WEAKENS LATE TONIGHT. NAM AND GFS ARE PRETTY SIMILAR WITH GFS BEING A LITTLE FURTHER SOUTH AND WEST WITH SFC LOW TRACK THAN THE NAM AND PRETTY SIMILAR IN STRENGTH AS WELL. GFS SHOWS THE DRY AIR ON I280K SURFACE WELL...BUT ERODES IT QUICKER OVER THE ERN CWA BY 6 HOURS WHERE IT HAS IT SATURATED AT KERY EARLIER THAN THE NAM DOES. AM A LITTLE AFRAID THAT THE GFS MIGHT BE RIGHT AS PAST EXPERIENCE HAS SHOWN THAT WITH STRONG LIFT AND DRY AIR IN THE AREA...THE DRY AIR ERODES AWAY FAIRLY QUICKLY AND HAVE GOTTEN BURNED ON THIS BEFORE WHERE PUSHED BACK PCPN TIMING AND PCPN STARTS OUT EARLIER THAN EXPECTED. ONLY PROBLEM THIS TIME IS STRONG EAST WINDS WILL KEEP ADVECTING IN THE DRY AIR. WILL BE INTERESTING TO SEE HOW LONG THE DRY AIR REMAINS AND CONFIDENCE OF WHEN THAT WILL OCCUR IS LOW. WILL FOLLOW A BLEND OF THE NAM AND GFS FOR THIS FORECAST. FOR TODAY...SLEET STILL LOOKS LIKE A POSSIBILITY WITH NAM BUFKIT SOUNDING FOR KMNM SHOWING A LAYER FROM 825 MB TO 735 MB SLIGHTLY ABOVE FREEZING AND KEPT SLEET IN THE FORECAST. ADDED A POSSIBILITY OF THUNDER NEAR LAKE MICHIGAN THROUGH THIS EVENING. QUICK LOOK AT BOTH THE GFS AND NAM BOTH SHOWED LAPSE RATES OF 6C TO 7C FROM 700-500MB MOVING ACROSS THE SOUTHERN CWA THROUGH THIS EVENING AND THIS AREA LINED UP WELL WITH WHERE LIGHTNING HAS BEEN SHOWING UP IN THE CORNBELT THIS MORNING ON THE LIGHTNING DETECTION SYSTEM. OVERALL...DID NOT MAKE TOO MANY CHANGES TO THE GOING FORECAST. BLIZZARD CONDITIONS IN THE KEWEENAW STILL LOOK ON TARGET AND DID NOT MAKE DRASTIC CHANGES TO THE FORECAST FOR TEMPERATURES OR WEATHER. DID DELAY PCPN OVER THE EAST AND NORTH A BIT WITH THE DRY AIR AND PUSHED TIMING BACK THERE FOR CATEGORICAL AND LIKELY POPS. OVERALL...THIS STORM SYSTEM LOOKS VERY DANGEROUS TO PEOPLE WITH BLIZZARD CONDITIONS AND PLENTY OF WET...HEAVY SNOW. IT WILL BE A DANGER TO TRAVEL. WENT CLOSE TO HPC GUIDANCE FOR QPF AND THINK THAT CWA WILL SEE A WIDESPREAD 12-18 INCH SNOWSTORM OUT OF THIS THROUGH FRIDAY. HEAVIEST SNOWFALL LOOKS TO BE TONIGHT WITH THE STRONGEST DYNAMICS AND MOISTURE MOVING ACROSS THE AREA. LAKE EFFECT AND ENHANCEMENT COME INTO PLAY FRIDAY NIGHT AS MOISTURE STARTS TO DEPART AND 850 MB TEMPERATURES FALL TO -14C TO -16C AND BUMPED UP AMOUNTS IN NORTHERN UPSLOPE AREAS OF MARQUETTE COUNTY FOR THIS REASON. COULD SEE 4-7 INCHES SNOW FRIDAY NIGHT. SATURDAY COULD AGAIN SEE MODERATE ACCUMULATIONS AS LAKE EFFECT REALLY KICKS IN AND DEEP MOISTURE STARTS TO MOVE OFF WITH THE WRAPAROUND AND THE STORM CONTINUES TO WEAKEN. 850 MB TEMPERATURES DO WARM SOME FROM -14C TO -16C IN THE MORNING TO -12C IN THE AFTERNOON. && .MQT WATCHES/WARNINGS/ADVISORIES... WINTER STORM WARNING FROM 4 PM THURSDAY TO 7 PM EST FRIDAY FOR MIZ006-007-014-085. WINTER STORM WARNING FROM 1 PM THURSDAY TO 7 PM EST FRIDAY FOR MIZ004-005-084. WINTER STORM WARNING UNTIL 7 PM EST FRIDAY FOR MIZ002-013. BLIZZARD WARNING FROM 4 PM THURSDAY TO 7 PM EST FRIDAY FOR MIZ001-003. WINTER STORM WARNING UNTIL 6 PM CST FRIDAY FOR MIZ009>012. STORM WARNING FOR LAKE SUPERIOR. && $$ MICHELS
AREA FORECAST DISCUSSION
NWS PORTLAND OR
815 PM PST FRI MAR 02 2007 .SYNOPSIS...A WARM FRONT OVER THE FORECAST AREA WILL SLOWLY WEAKEN OVERNIGHT. AN UPPER LEVEL RIDGE OFFSHORE WILL GRADUALLY STRENGTHEN AND MOVE CLOSER TO THE COAST SATURDAY. THIS WILL ALLOW THE AIR MASS TO SLOWLY DRY DURING THE DAY. A WEAK FRONT IS EXPECTED TO MOVE ACROSS THE REGION AROUND SUNDAY NIGHT...BUT A MUCH STRONGER AND WETTER SYSTEM CAN BE EXPECTED TUESDAY. A COOLER AIR MASS WILL SPREAD OVER THE FORECAST AREA WEDNESDAY. A SERIES OF DISTURBANCES CAN BE EXPECTED TO AFFECT THE REGION DURING THE MIDDLE AND LATTER PARTS OF NEXT WEEK. && .SHORT TERM...WARM FRONT STILL IMPACTING SOUTHWEST WASHINGTON AND NORTHWEST OREGON THIS EVENING. NWS PORTLAND DOPPLER RADAR LOOPER CONTINUES TO SHOW A STEADY STREAM OF RETURNS. RAINFALL RATES HAVE BEEN LESS THAN A TENTH OF AN INCH PER HOUR. FREEZING LEVELS HAVE STEADILY RISEN SINCE THIS MORNING. 00Z KSLE SOUNDING SHOWED A FREEZING LEVEL OF 5700 FEET. AN ACARS SOUNDING NEAR KPDX AT 0145Z INDICATED A FREEZING LEVEL OF 5900 FEET. SNOW LEVELS PRETTY MUCH CONFINED TO ABOUT 5000 FEET AND HIGHER. THE 5000 FOOT SENSOR AT GOVT. CAMP SHOWED 32 DEG AT 02Z. A LITTLE HIGHER UP...MT. HOOD MEADOWS REPORTED 30 DEG AT 6600 FT. SNOWFALL AMOUNTS AT THE SKI RESORTS HAVE BEEN ON THE ORDER OF AN INCH OR TWO SINCE LATE THIS AFTERNOON. 12- HOUR AMOUNTS AT TIMBERLINE AND MT.HOOD MEADOWS GENERALLY 3 TO 6 INCHES. 850 MB FLOW TONIGHT NOT AS FAVORABLE FOR EXTRA OROGRAPHIC SUPPORT. GENERALLY LOOKING AT SW 850 MB WIND OF 15-20 KT. LATEST GUIDANCE SUGGESTS QPF OVERNIGHT TO WANE AS 500 MB RIDGE ALONG 130W SLOWLY EXPANDS NWD. THEREFORE...WILL ALLOW THE CASCADE SNOW ADVISORY TO END AS SCHEDULED. THE 500 MB RIDGE CONTINUES TO AMPLIFY ALONG THE COAST LATE TONIGHT AND SAT. THIS WILL FORCE THE RESIDUAL BAROCLINIC ZONE OUT OF THE FORECAST AREA BY SAT AFTERNOON. NEED TO LEAVE SOME POPS SAT MORNING...BUT AFTERNOON LOOKS DRY EXCEPT POSSIBLY SOME RESIDUAL LIGHT PRECIP IN SW WA. LATEST NAM SHOWS 850 MB TEMPS OF +5C SAT AFTERNOON. SOUTH PART OF THE FORECAST AREA LIKELY TO GET UP INTO UPPER 50S. STILL SOME QUESTIONS ABOUT SUN. NAM HAS COME AROUND THE GFS IDEA OF A WEAK DISTURBANCE SKIRTING THE TOP OF THE WEAKENING RIDGE. GFS MORE ROBUST WITH THIS FEATURE THAN NAM AND THIS SHOWS UP IN THE FORECAST TEMP GUIDANCE. NAM TEMP GUIDANCE FOR SUN INDICATES MID TO UPPER 50S...BUT 18Z MAV NUMBERS WERE SEVERAL DEGREES COOLER. 00Z MAV TEMPS MORE IN LINE WITH THE MET AND FWC AND HAVE TRENDED TOWARD THESE VALUES. THE UPPER RIDGE AXIS PUSHES E BY SUN ALLOWING A CHANCE OF RAIN BY AFTERNOON WITH WEAK LIFT AS A SYSTEM LIFTS NE THROUGH THE AREA. WEISHAAR .LONG TERM...MODELS REMAIN CONSISTENT IN LAYING UP A BAROCLINIC ZONE OVER THE FORECAST AREA MON NIGHT THROUGH TUE NIGHT. THIS SYSTEM APPEARS TO HAVE A TROPICAL MOISTURE TAP ASSOCIATED WITH IT AND FREEZING LEVELS WILL LIKELY BE NEAR THE CASCADE CREST. GFS ENSEMBLE MEAN PRECIPITATION INDICATING AROUND 2-3 INCHES IN THE MOUNTAINS AND AROUND 1 INCH OR SO IN THE WILLAMETTE VALLEY MON NIGHT THROUGH TUE NIGHT. THIS WILL NEED TO BE WATCHED AS 18Z GFS SHOWED WAVE DEVELOPMENT ALONG THE BAROCLINIC ZONE TUE WHICH WOULD RESULT IN PROLONGED PRECIP. AFTER TUE NIGHT IT APPEARS A COOLER AIR MASS SPREADS OVER THE FORECAST AREA WITH A SERIES OF SHORT-WAVES ASSOCIATED WITH IT. COULD BE ANOTHER GOOD SHOT OF SNOW FOR THE CASCADES IF THIS PANS OUT. WEISHAAR && .AVIATION...EXPECT MOSTLY MVFR CONDITIONS OVER THE AREA WITH LOCAL IFR CONDITIONS IN RAIN DRIZZLE AND FOG AS A STRONG WET WARM FRONT LINGERS OVER NW OREGON OVERNIGHT. CONDITIONS EXPECTED TO IMPROVE TO GENERALLY VFR BY SATURDAY AFTERNOON. && .MARINE...SEAS WILL BUILD TO 10 FT LATER TONIGHT AND SAT AND SUBSIDE BELOW 10 FT SATURDAY AFTERNOON. A VERY STRONG COLD FRONT IS EXPECTED TO MOVE ACROSS THE WATERS MONDAY EVENING THROUGH EARLY TUE WITH GALE FORCE WINDS AND POSSIBLY EVEN SOME STORM FORCE GUSTS...ACCOMPANIED BY COMBINED SEAS BUILDING AT LEAST INTO THE TEENS. && .PQR WATCHES/WARNINGS/ADVISORIES... .OR/WA...SMALL CRAFT ADVISORY FOR SEAS CAPE SHOALWATER TO FLORENCE THROUGH SAT AFTERNOON. SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA BAR THIS AFTERNOON LATE TONIGHT AND SAT AFTERNOON. && .PRELIMINARY POINT POPS... AST +6-357 PDX +4-325 SLE 93-225 EUG 91-225 $$ MORE WEATHER INFORMATION ONLINE AT... http://weather.gov/portland THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON FROM THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS COMMONLY REFERRED TO AS THE FORECAST AREA.
AREA FORECAST DISCUSSION
NWS SEATTLE WA
320 AM PST THU MAR 1 2007 .SYNOPSIS...A PUGET SOUND CONVERGENCE ZONE WILL CONTINUE TO BRING SNOW TO THE EVERETT AREA THIS MORNING. THE CONVERGENCE ZONE WILL DISSIPATE BY AFTERNOON. A COOL TROUGH OF LOW PRESSURE OVER THE AREA TODAY WILL SHIFT EAST. A WEAK SYSTEM WILL SLIDE BY TO THE SOUTH TONIGHT WITH A STRONGER AND WARMER SYSTEM ARRIVING ON FRIDAY. THE FRONT WILL LIFT INTO BRITISH COLUMBIA ON SATURDAY. A SERIES OF WEATHER SYSTEMS WILL MOVE THROUGH THE AREA THE FIRST PART OF NEXT WEEK. && .SHORT TERM...THE CONVERGENCE ZONE THAT WONT DISSIPATE CONTINUES NEAR THE KING SNOHOMISH COUNTY LINE THIS MORNING. THE COMBINATION OF THE UPPER LEVEL TROUGH OVER THE AREA THIS MORNING SHIFTING EAST AND THE SURFACE GRADIENTS IN THE STRAIT GOING WEAKLY OFFSHORE THIS AFTERNOON WILL RESULT IN THE CONVERGENCE ZONE DISSIPATING FOR GOOD. WILL KEEP A SNOW ADVISORY GOING FOR THE EVERETT AREA FOR ANOTHER ONE TO THREE INCHES THIS MORNING. FOR THE REMAINDER OF THE AREA THE UPPER LEVEL TROUGH IS STILL OVER THE AREA THIS MORNING KEEPING THE THREAT OF SHOWERS IN THE FORECAST. THE AMS OVER WESTERN WASHINGTON REMAINS COOL WITH ACARS SOUNDINGS SHOWING THE FREEZING LEVEL HOVERING NEAR 1000 FEET. THIS MEANS ANY SHOWER ACTIVITY THIS MORNING WILL BE IN THE FORM OF SNOW BUT QPF VALUES ARE LIGHT SO EXPECT ACCUMULATIONS...IF THERE ARE ANY...TO BE BELOW AN INCH. TROUGH KICKS EAST THIS AFTERNOON WITH THE NEXT SYSTEM CURRENTLY OUT NEAR 45N/130W MOVING INLAND SOUTH OF THE AREA. HAVE CUT BACK THE POPS FOR MOST LOCATIONS TONIGHT. A WARM FRONT CURRENTLY DEVELOPING BACK NEAR 160W WILL MOVE EAST TODAY AND TONIGHT AND MOVE OVER WESTERN WASHINGTON ON FRIDAY AND FRIDAY NIGHT. AT THE SAME TIME A FLAT UPPER LEVEL RIDGE WILL TRY TO BUILD ALONG THE WEST COAST. AT THE POINT IT LOOKS LIKE THE RIDGE WILL BE STRONG ENOUGH TO PUSH THE FRONT NORTH INTO BRITISH COLUMBIA ON SATURDAY WITH THE COLD FRONT REMAINING WELL OFFSHORE. .LONG TERM...MODELS STILL SHOWING GOOD RUN TO RUN CONSISTENCY WITH AN UPPER LEVEL RIDGE ALONG THE WEST COAST ON SUNDAY BUT THE RIDGE AXIS IS EAST OF WESTERN WASHINGTON WHICH LEAVES THE DOOR OPEN FOR A WEAK SYSTEM EMBEDDED IN THE SOUTHWESTERLY FLOW ALOFT TO MOVE OVER THE AREA. WILL STAY WITH THE CHANCE POPS FOR NOW. WEAKENING COLD FRONT MOVING THROUGH THE CWA ON MONDAY WITH A STRONGER SYSTEM ARRIVING ON TUESDAY. CURRENT MODEL SOLUTIONS HAVE THE SYSTEM ON WEDNESDAY GOING BY MAINLY TO THE NORTH BUT GIVEN THE ZONAL FLOW WILL STAY WITH LIKELY POPS FOR NOW. FELTON && .AVIATION...PSCZ AT TIMES THROUGH THE MORNING FOR LCL VIS BLO 3SM -SHSN AND LOWER CIGS. OUTSIDE THE PSCZ CONDITIONS ARE GENERALLY VFR WITH JUST ISOLATED SHOWERS AND SCT-BKN050. THE COLD UPPER TROF GIVES WAY TO STABILIZING AND WARM ADVECTION TONIGHT AND MODEL CROSS SECTION SUGGESTS BKN050 PERSISTS...THEN INCREASING HIGHER LAYERS IN WARM ADVECTION. $$ .SEW WATCHES/WARNINGS/ADVISORIES... .SMALL CRAFT ADVISORY COASTAL WATERS FOR HAZARDOUS SEAS. .SMALL CRAFT ADVISORY FOR ROUGH BAR CONDITIONS GRAYS HARBOR BAR. .SNOW ADVISORY FOR THE EVERETT AREA THIS MORNING $$
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
1230 AM EST SAT MAR 3 2 2007 .AVIATION (06Z TAFS)... WINDS DIMINISHED OVER CENTRAL KENTUCKY AND SOUTH CENTRAL INDIANA THIS EVENING WITH MOST SPEEDS BETWEEN 6 AND 10 KTS. PRESSURE GRADIENT WILL NOT WEAKEN MUCH OVERNIGHT AND EXPECT WINDS TO STAY BETWEEN 5 AND 10 KTS OVERNIGHT. SOME LIGHT RADAR RETURNS PERSIST OVER LMK/S EASTERN COUNTIES BUT NO REPORTS OF ANY PRECIPITATION REACHING THE GROUND. CLOUDS ARE MOSTLY MID LEVEL (9-11 THSD FT) OVER CWA AND WILL INDICATE THIS IN TAFS. MAIN CONCERN FOR DAYTIME ON SATURDAY WILL BE CLOUDS AND ANY PRECIPITATION ACCOMPANYING TROUGH (UPPER LEVEL AND SURFACE) THAT WILL PUSH INTO THE AREA LATE MORNING INTO THE AFTERNOON. EXPECT CLOUDS AND TROUGH TO REACH SDF FIRST THEN LEX AND BWG 1 TO 2 HOURS LATER. WINDS WILL INCREASE LATE MORNING AS DAYTIME HEATING ALLOWS HIGHER WINDS ALOFT TO MIX DOWN TO SURFACE. LAPSE RATES EXPECTED TO REMAIN STEEP...ESPECIALLY AFTER LATE MORNING...CREATING ENOUGH INSTABILITY FOR SCATTERED SHOWERS TO DEVELOP. MORE MOISTURE IS AVAILABLE TODAY THAN ON FRIDAY SO EXPECT CLOUDS AND SOME SHOWERS TO DEVELOP. MOST OF THESE CLOUDS WILL BE IN THE 3 TO 4 THSD FOOT RANGE. SCHOLZ && .UPDATE... STRONG WINDS AT LEX HAVE BEEN MORE PERSISTENT THAN EXPECTED EARLIER...AND HAVE ISSUED ANOTHER SPS FOR THE BLUEGRASS THROUGH 1030 PM EST TO COVER THESE GUSTS. SHOULD SEE A DIMINISHING TREND AFTERWARD. IN OTHER SECTIONS OF THE CWA WINDS HAVE SUBSIDED. AREA OF MID/HIGH LEVEL CLOUDS CURRENTLY OVER THE CWA ASSOC WITH UPPER LEVEL JET STREAK ARE PRODUCING SOME DECENT RADAR RETURNS OVER SRN/ERN PARTS OF THE CWA. EVEN IN THE PRESENCE OF 25-30 DEGREE T-TD SPREADS...FEEL THAT AT LEAST SOME SPRINKLES ARE POSSIBLE THROUGH THE EARLY OVERNIGHT PERIOD IN THESE AREAS. WILL UPDATE THE FCST TO ACCOUNT FOR THIS. BASED ON LATEST OUTPUT FROM NAM/RUC...PCPN ASSOC WITH VIGOROUS UPPER WAVE OVER MIDWEST SHOULD HOLD OFF UNTIL MID-DAY SATURDAY...WHICH IS IN-LINE WITH CURRENT FCST. UPDATED FCST OUT BY 10 PM EST. CS && .SHORT TERM (TONIGHT AND SATURDAY) SOME MAJOR PROBLEMS TO DEAL WITH IN THE SHORT TERM. FIRST AND FOREMOST IS THE STRONG AND GUSTY WINDS THIS AFTERNOON AND EVENING. A TIGHT PRESSURE GRADIENT AROUND THE DEEP GREAT LAKES LOW PRESSURE IS CAUSING WIND GUSTS FROM 40 TO 50 MPH AT TIMES ACROSS N CNTRL KY AND S CNTRL INDIANA THAT WILL DIMINISHING DURING THE EVENING HOURS. SO KEPT THE WIND ADVISORY ACROSS THE SAME AREA UNTIL 00Z TONIGHT. ON SATURDAY AS THE CLOSED 500 MB LOW OVER STARTS TO LIFT EAST NORTHEAST TOWARDS SOUTHERN CANADA...A RATHER VIGOROUS SHORT WAVE ROTATES AROUND THE SOUTH SIDE AROUND THIS CLOSED CIRCULATION AND BRINGS A BURST OF COLDER AIR THAT IS RELATIVELY MOIST IN THE LOWER LEVELS UP TO ABOUT THE 700 MB LEVEL. THERE IS ALSO SOME DECENT SYNOPTIC SCALE LIFT...SO THERE IS AT LEAST A CHANCE OF RAIN OR SNOW ON SATURDAY. WILL GO WITH 30 PERCENT NRN TWO THIRDS OF FA AND 20 PCT ACROSS THE SOUTH. WITH INCREASED CLOUDS AND PCPN THREAT ALONG WITH GOOD COLD AIR ADVECTION...WILL GO WITH MAX TEMPS A FEW DEGS BELOW THE MAV FCSTS FOR SATURDAY. THIS AGREES WELL WITH IND..ILN AND PAH FCSTS TOO. --21 .LONG TERM (SATURDAY NIGHT THROUGH FRIDAY)... MEDIUM AND LONG TERM MODELS HAVE BEEN FAIRLY CONSISTENT THE LAST FEW DAYS...LATEST DAY 5 AND 6 VERIFICATION SCORES SHOW THE CANADIAN LEADING THE PACK THE LAST TWO DAYS WITH THE EURO AND GFS JUST BEHIND. GFS HAS BEEN SOLID THROUGH DAY 5...WILL FOLLOW THERE AND THEN LEAN TOWARDS THE EURO THROUGH THE REST OF THE PERIOD...IT HAS BEEN STABLE AND HAS MUCH SUPPORT FROM THE HIGH PERFORMING CANADIAN. SATURDAY NIGHT THROUGH MONDAY... UPPER LEVEL TROUGH ROTATING THROUGH THE FORECAST AREA SATURDAY NIGHT WILL CREATE SOME FORCING...ALONG WITH A MODEST AMOUNT OF MOISTURE THROUGH THE COLUMN...WILL ALLOW FOR CHANCE OF SNOW SHOWERS THROUGH THE NIGHT. LITTLE ACCUMULATION...BUT A SLIGHT WHITENING OF SURFACES LOOKS POSSIBLE. MUCH DRIER AIR STARTS TO ADVECT INTO THE OHIO VALLEY EARLY SUNDAY FROM THE WEST AS THE UPPER LEVEL TROUGH MOVES EAST OF THE APPALACHIANS. COLD DAY SUNDAY WITH THE COMBO OF H850 TEMPS NEAR -10C AND SOME LINGERING CLOUDS EARLY...BUT WILL GIVE FINALLY TO ALLOW FOR A MOSTLY SUNNY AFTERNOON. BOTH SATURDAY NIGHT AND SUNDAY MAY BE SOMEWHAT BREEZY WITH SOME GUSTS NEAR 25 MPH POSSIBLE. SLIGHT WAA DEVELOPS LATE SUNDAY AS SURFACE HI SHIFTS FROM THE SOUTHERN ROCKIES INTO THE WESTERN GULF STATES BRINGING WARMER AIR IN FROM THE PLAINS. H850 TEMPS CLIMB TO AROUND +2C BY MONDAY AFTERNOON AND NEAR FULL SUN...TEMPS WILL CLIMB BACK TO SEASONAL EARLY MARCH LEVELS. TUESDAY THROUGH FRIDAY AREA SANDWICHED BETWEEN THE RIDGING ACROSS THE WESTERN PLAINS AND THE NORTHEASTERN TROUGH...CREATING A WNW FLOW OVER THE OHIO VALLEY. TROUGH CONTINUES TO SLOWLY MOVE FURTHER EAST OFF THE COAST WITH INCREASING HEIGHTS OVER THE OHIO VALLEY INTO THURSDAY AS THE RIDGING FLATTENS AND DRIFTS EAST TOWARDS THE REGION. PATTERN BECOMES NEARLY ZONAL OVER THE ENTIRE CONUS BY FRIDAY. BACKDOOR COLD FRONT LOOKS TO PUSH INTO OR NEAR THE FORECAST AREA TUESDAY...AS LARGE SURFACE HIGH MOVES FROM JUST SOUTH OF HUDSON BAY INTO THE NORTHEAST BY WEDNESDAY MORNING. TEMPS MAY EB SLIGHTLY COOLER TUESDAY THAN MONDAY AS A FEW MORE CLOUDS AND SLIGHTLY COOLER AIR ALOFT WORKS INTO THE MID OHIO VALLEY. AS THE RIDGING MOVES MORE INTO THE AREA ALONG WITH A MORE SOUTHERLY FLOW WEDNESDAY INTO THURSDAY TEMPS LOOKS TO BE ABOVE NORMAL EACH DAY WITH PLENTY OF SUNSHINE. COLD FRONT LOOKS TO BE POISED TO DROP INTO THE FORECAST AREA ON FRIDAY...AS CLOUDS INCREASE EARLY. AREA OF LOW PRESSURE WILL DEVELOP ACROSS THE SOUTHERN PLAINS AND MOVE UP THROUGH THE REGION DURING THE DAY...WITH BEST PRECIP CHANCES LOOKING TO BE IN THE AFTN/EVEN. TEMPERATURES DO NOT LOOK AS COOL BEHIND THE FRONT AS THEY DID THE LAST FEW RUNS...WHICH GOES INLINE BETTER WITH THE LATEST INDICES(PNA/NAO/EPO). THEY CONTINUE TO INDICATE THE PERIOD THROUGH THE MIDDLE OF MONTH SHOULD FAVOR AT LEAST NORMAL TO SLIGHTLY ABOVE NORMAL. SCHOTT && .AVIATION (00Z TAFS)... IMPRESSIVE WINDS THIS AFTERNOON OVER THE ENTIRE CWA WITH GUSTS AS HIGH AS 46KTS AT KLEX AROUND 21Z. STEEP LAPSE RATES UP TO 600MB ON RECENT ACARS SOUNDINGS FROM KSDF...MORE REMINISCENT OF SOUNDINGS SEEN IN THE HIGH PLAINS DURING THE SUMMER. WINDS ARE FCST TO DROP OFF DRAMATICALLY BETWEEN 0Z-2Z THIS EVENING PER LATEST RUC. EVEN WITH SCT RADAR RETURNS...LITTLE IF ANY PRECIP FCST TO REACH THE SFC THIS EVENING GIVEN TEMP-DWPT SPREADS ON THE ORDER OF 35 DEGREES. THEY WOULD CERTAINLY NOT BE ENOUGH TO RESTRICT VSBYS AT TAF SITES...BUT ANY VIRGA WOULD BE CAPABLE OF PRODUCING LOCALIZED DOWNDRAFTS. VERY LATE TONIGHT...BUT MORE SO TOMORROW...CHCS FOR -SHRA ARE FCST...WITH A FEW -SHSN POSSIBLE AT SDF/LEX TERMINALS DURING THE AFTN AS BOUNDARY LAYER COOLS PER NAM FCST SOUNDINGS. WILL HANDLE WITH VCSH FOR TIME BEING DUE TO UNCERTAINTIES IN COVERAGE. CS && .LMK WATCHES/WARNINGS/ADVISORIES... KY...NONE. IN...NONE. && $$
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
435 AM EST SAT MAR 3 2007 .DISCUSSION... MAIN FCST ISSUES ARE FATE OF ONGOING HEADLINES AND TIMING THE END OF SNOW AS DECAYING STORM SYSTEM OVER THE GREAT LAKES HEADS E. WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW MIDLEVEL LOW CONTINUING TO FILL AS IT TRACKS E ACROSS NRN LWR MI EARLY THIS MORNING. MOISTURE WRAPPING AROUND THE SYSTEM STILL ENCOMPASSES UPPER MI/LAKE SUPERIOR. DEEP MOISTURE/CYCLONIC FLOW COMBINED WITH 850MB TEMPS RANGING FROM ABOUT -14C SCNTRL LAKE SUPERIOR TO -16C WRN LAKE SUPERIOR PER 06Z RUC ANALYSIS IS RESULTING IN LAKE ENHANCED SNOW IN N WIND FAVORED LOCATIONS. 850MB TEMPS ARE PROBABLY LOWER THAN RUC ANALYSIS OVER THE W AS 05Z TAMDAR SOUNDING FROM CYQT SHOWED 850MB TEMP OF -19C. IT ALSO APPEARS 850MB TEMPS HAVE DROPPED A BIT MORE RECENTLY OVER CNTRL LAKE SUPERIOR AS LES BANDS ARE BEGINNING TO FORM IN WHAT HAD BEEN AN AREA OF SNOW WITH LITTLE STRUCTURE/ORGANIZATION. KDLH RADAR HAS OCCASIONALLY SHOWED BANDS STREAMING INTO FAR WRN UPPER MI NEAR KIWD...SO DECENT SNOW HAS BEEN OCCURRING IN THAT AREA OVERNIGHT. HAD A REPORT JUST AFTER MIDNIGHT OF MDT TO HVY SNOW ON THE KEWEENAW IN THE PHOENIX/DELAWARE AREAS. SNOW OVERNIGHT HAS HAD A HIGH SNOW TO WATER RATIO AS EXPECTED DUE TO 7-10KFT LAYER OF FAVORABLE DENDRITIC SNOW GROWTH TEMPS IN THE MOIST LAYER. MODELS ARE IN GOOD AGREEMENT TAKING MIDLEVEL LOW TO SRN QUEBEC BY 00Z SUN...AND NAM/GFS ARE NOW ALSO IN GOOD AGREEMENT BRINGING BACK EDGE OF DEEP MOISTURE W TO E ACROSS THE FCST AREA TODAY/TONIGHT. IT SHOULD REACH THE WRN FCST AREA LATE MORNING/EARLY AFTN AND CLEAR THE FAR ERN FCST AREA MID/LATE EVENING. AT THE SAME TIME...CYCLONIC FLOW WILL RELAX AND BECOME NEUTRAL THEN ANTICYCLONIC FROM W TO E. EVEN THOUGH 850MB TEMPS WILL RANGE FROM -13C TO -16C TO SUPPORT LES THRU THE DAY...DEPARTURE OF DEEP MOISTURE WILL RESULT IN A SHARP DIMINISHING TREND BEFORE SHSN END W THIS EVENING AND E LATE TONIGHT. WITH EXPECTED FLUFFY ACCUMULATIONS OF 1 TO 3 INCHES W AND 1 TO 4 INCHES NCNTRL TODAY...WILL NEED TO EXTEND HEADLINES EVEN THOUGH A FEW INCHES OF THIS LOW WATER CONTENT SNOW WILL REALLY NOT BE MUCH MORE THAN A NUISANCE COMPARED TO WHAT THE AREA EXPERIENCED THU NIGHT/FRI. PERIOD OF MOSTLY CLEAR/PARTLY CLOUDY SKIES WILL FOLLOW FROM W TO E TONIGHT/SUN MORNING. RIBBON OF ISENTROPIC ASCENT (290K SFC) ASSOCIATED WITH A WEAK SHORTWAVE DIVING SE TOWARD THE UPPER LAKES WILL PASS ACROSS THE AREA LATE TONIGHT THRU EARLY SUN AFTN. EVEN SO...IT LOOKS LIKE A GOOD PORTION OF THE NIGHT WILL BE MOSTLY CLEAR/PARTLY CLOUDY OVER ROUGHLY THE W HALF OF FCST AREA. THIS SHOULD ALLOW FOR DECENT RADIATIONAL COOLING AS WEAK SFC RIDGE PASSES. HAVE THUS FAVORED THE LOWER SIDE OF MOS GUIDANCE OVER THE INTERIOR W. CLOUDS WILL LINGER THRU MOST IF NOT ALL OF THE NIGHT OVER THE FAR E...KEEPING MINS HIGHER THERE THAN OVER THE W. RIBBON OF MID/HIGH CLOUDS WILL PROGRESS ACROSS THE AREA SUN...AND IT APPEARS TO BE FOLLOWED BY A LOWER STRATOCU DECK PER GFS/NAM RH PROGS. LOW-LEVEL ISENTROPIC ASCENT WITH LOW CONDENSATION PRES DEFICITS ON THE 275K SFC (ROUGHLY AROUND 900MB) SUPPORTS THE IDEA OF SCT/BKN LOWER CLOUDS SWEEPING INTO THE AREA SUN AFTN/EVENING. THESE CLOUDS WILL BE AHEAD OF A STRONGER SHORTWAVE HEADING SE INTO ONTARIO. PRES GRADIENT TIGHTENS AHEAD OF FEATURE WITH NAM/GFS SHOWING WRLY 950MB WINDS RAMPING UP TO 35 TO 40KT SUN AFTN/EVENING AHEAD OF APPROACHING ARCTIC FRONT...SUPPORTING POTENTIAL OF GALES ON LAKE SUPERIOR. REGARDING SHORTWAVE...NAM IS QUITE A BIT STRONGER WITH FEATURE THAN GFS/UKMET/CANADIAN...AND IT IS ABOUT 6 HRS SLOWER WITH FROPA. SEE NO REASON NOT TO FOLLOW BULK OF GUIDANCE WITH REGARD TO DETAILS. WRLY GALES AHEAD OF FRONT WILL SHIFT TO A PERIOD OF NW GALES AFTER FROPA SUN NIGHT UNDER STRONG CAA REGIME (850MB TEMPS FALL FROM AROUND -10C SUN EVENING TO AROUND -20C BY MON MORNING). WITH 850MB TEMPS TOO HIGH TO SUPPORT LES PRIOR TO FROPA...NOT REALLY EXPECTING A SIGNIFICANT BAND OF SNOW ALONG ARCTIC FRONT AS IT PASSES. IN ADDITION...BULK OF FORCING WITH SHORTWAVE PASSES NE OF FCST AREA. AT THIS POINT...CHC POPS LOOK FINE WITH FROPA SUN NIGHT. HEALTHY SUBSIDENCE/DRY AIR AND INVERSION SETTLING TO AROUND 4KFT ON MON SUGGEST LES WILL BE ON THE LIGHT SIDE DESPITE 850MB TEMPS IN THE -20 TO -23C RANGE. ARCTIC HIGH PRES RIDGE BUILDS SE OVER THE UPPER LAKES/ONTARIO MON NIGHT...SETTING UP WHAT WOULD APPEAR TO BE A VERY COLD NIGHT OVER THE INTERIOR W AND CNTRL FCST AREA. HOWEVER...MODELS ARE FAIRLY AGGRESSIVE IN SPREADING CONSIDERABLE MID/HIGH LEVEL MOISTURE INTO THE AREA DOWNSTREAM OF DEVELOPING WAA PATTERN OVER THE NRN PLAINS/UPPER MISSISSIPPI VALLEY. NOT SURE HOW LONG THE WINDOW WILL BE FOR RADIATIONAL COOLING...BUT WILL TAKE A CONSERVATIVE APPROACH ON TEMP DROP MON NIGHT...GOING A FEW DEGREES ABOVE LATEST GFS MOS GUIDANCE. SHOULD BULK OF NIGHT END UP CLEAR...TEMPS WOULD LIKELY FALL TO -15F IN THE TYPICAL COLD SPOTS. BEYOND MON NIGHT...REST OF NEXT WEEK SHOWS PLENTY OF UNCERTAINTY WITH A SERIES OF SHORTWAVES RUNNING ALONG BOUNDARY BTWN ARCTIC AIR IN CANADA AND MILD AIR COVERING MUCH OF THE CNTRL CONUS. FIRST OF THESE WILL ARRIVE TUE...AND GOING FCST HAS THIS COVERED WELL WITH -SN CHC POPS. NO CHANGES NEEDED BEYOND TUE. && .MQT WATCHES/WARNINGS/ADVISORIES... WINTER STORM WARNING UNTIL 18Z TODAY MIZ002-004-009. WINTER STORM WARNING UNTIL 23Z TODAY MIZ005. SNOW AND BLOWING SNOW ADVY UNTIL 18Z TODAY MIZ001-003. SNOW AND BLOWING SNOW ADVY UNTIL 23Z TODAY MIZ006. GALE WARNING LAKE SUPERIOR. && $$ ROLFSON
AREA FORECAST DISCUSSION...UPDATED
NWS MOUNT HOLLY NJ
1035 AM EST SAT MAR 3 2007 .UPDATE /REST OF TODAY/... CLOUDS ARE STARTING TO WORK THEIR WAY INTO THE REGION FROM CENTRAL PENNSYLVANIA. SOME STRATOCU AND MORE SO SOME ALTOCU ARE CURRENTLY INTO THE POCONOS AND LEHIGH VALLEY. WITH PLENTY OF SUNSHINE EARLY THIS MORNING, TEMPERATURES RECOVERED NICELY OFF THEIR MORNING LOWS. AT 900 AM...THE POCONOS WERE ALREADY IN THE 40S WITH MID 50S ACROSS SOUTHERN NJ AND DELMARVA. I DIDN`T MAKE ANY SIGNIFICANT CHANGES TO THE TEMPERATURES TODAY AS THE FORECAST WAS ALREADY CLOSER TO THE WARMER ETA STAT GUIDANCE. WHILE THE CENTRAL AND SOUTHERN ZONES STILL HAVE SOME ROOM TO WARM, THE FAR NORTHERN ZONES MAY PRETTY MUCH BE DONE. CLOUDS ARE ON THE INCREASE, AS MENTIONED, AND BASED ON THE SURFACE TEMP/DEWPOINT SPREAD AND VERTICAL SOUNDINGS, THERE`S A GOOD CHANCE THAT SOME EVAPORATIVE COOLING WILL END UP AS PART OF THE EQUATION THIS AFTERNOON. WITH THAT SAID, BOTH RAIN AND SNOW SHOWERS WERE LEFT IN PLACE ACROSS THIS AREA. FURTHER TO THE SOUTH, NO CHANGE IN PTYPE WAS MADE EITHER. I`LL STILL CALL IT LIQUID. IN TERMS OF THE PRECIPITATION THREAT TODAY, WHILE THE ETA STAT GUIDANCE WAS LARGELY PREFERRED FOR AFTERNOON TEMPERATURES, THE GFS FIELDS, PARTICULARLY THE H8 FRONTOGENESIS FIELDS AT 12Z, WERE SPOT ON AND PREFERRED. IT NICELY DEFINED TWO SEPARATE AREAS OF FORCING WHICH MESHED VERY WELL WITH RADAR TRENDS. AS THE DAY PROGRESSES, THE GFS CONSOLIDATES THE FORCING AS THE MID LEVEL TROF NEARS. THE CHANCE POPS WERE KEPT IN PLACE WITH THE "BETTER" CHANCES REMAINING FURTHER TO THE NORTH. WITH VERTICAL MIXING IMPROVING OVER THE THE NEXT FEW HOURS, THE AREA COULD SEE WINDS INCREASE AS THINGS GO ADIABATIC. THE 06Z GFS HAD HIGHER WIND SPEEDS BETWEEN ~H9-H7 THEN COMPARED TO THE NAM. WHEN COMPARED TO AREA 12Z RAOBS AND LOCAL ACARS DATA, THE LESS PRONOUNCED NAM LOOKED MORE APPROPRIATE. WE`LL MAINTAIN THE PEAK GUSTS THIS AFTERNOON AT 25 MPH. BEST CHANCES TO SEE THESE GUSTS WILL BE IN AND AROUND THE SCATTERED CONVECTIVE SHOWERS THAT ARE EXPECTED TODAY. HYDRO-WISE, NEW RFC GUIDANCE IS IN. WE`LL BE ABLE TO DROP THE WARNINGS FOR THE ROCKAWAY AT BOONTON BELOW AND THE MILLSTONE AT BLACKWELLS MILLS. WE`RE GOING TO WAIT FOR AFTERNOON GUIDANCE BEFORE WE DO ANYTHING WITH PINEBROOK ON THE PASSAIC. THE RANCOCAS IS STILL EXPECTED TO REMAIN BELOW FLOOD STAGE. KRUZDLO && .PHI WATCHES/WARNINGS/ADVISORIES... PA...NONE. NJ...NONE. DE...NONE. MD...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EST SUNDAY FOR ANZ450>455. $$ .SYNOPSIS... STRONG SHORT WAVE TROUGH TO MOVE OUT OF NORTHEAST U.S. OVER NEXT 48 HOURS. NW FLOW IN WAKE OF TROUGH WILL USHER IN ANOTHER SHOT OF WINTER TYPE TEMPERATURES FOR EARLY NEXT WEEK. TEMPERATURES MODERATE LATER IN THE WEEK AS FLOW PATTERN OVER U.S. BECOMES MORE ZONAL. && .SHORT TERM /TODAY THROUGH MONDAY NIGHT/... TO THUNDER OR NOT TO THUNDER...THAT IS THE QUESTION. HAVE CONTINUED WITH PREVIOUS FORECAST MENTIONING CHANCE OF PRECIPITATION MAINLY FOR THE AFTERNOON HOURS AS SHORT WAVE WITH VERY COLD TEMPERATURES ALOFT ROTATES OVER THE FORECAST AREA. HAVE KEPT THUNDER OUT OF THE FORECAST ON THIS PACKAGE AS WAS NOT CONVINCED WE HAVE ENOUGH PARAMETERS COMING TOGETHER. HOWEVER SPC STILL HAS GENERAL THUNDER OVER THE REGION FOR TODAY. SOUNDINGS DO FAVOR SOME STRONG GUSTY WINDS WITH ANY CONVECTIVE SHOWERS WHICH DEVELOP. WILL MENTION POTENTIAL FOR STRONG WIND GUSTS TODAY WITH SHOWERS IN THE HWO. COOLER AIRMASS MOVES INTO THE REGION ON SUNDAY IN THE WAKE OF THE SHORTWAVE. DID NOT MAKE ANY SIGNIFICANT CHANGES TO PREVIOUS FORECAST IN THIS TIME FRAME. NEXT FRONTAL BOUNDARY APPROACHES LATE MONDAY. && .LONG TERM /TUESDAY THROUGH FRIDAY/... LONG TERM PERIOD STARTS OFF IN WINTER AS ANOTHER SHOT OF ARCTIC AIR COMES SURGING INTO THE REGION. BOTH 18Z AND 00Z GFS MODEL RUNS TAKE SHORTWAVE MOVING THRU THE REGION TUE NIGHT AND WED AS A CLIPPER TYPE SYSTEM WITH LIGHT QPF AMOUNTS. DID NOT MAKE A CHANGE TO THE FORECAST FOR THIS FEATURE BUT IT BEARS WATCHING FOR CONTINUED MODEL CONTINUITY. TEMPERATURES REBOUND TOWARD THE END OF THE PERIOD AS FLOW ALOFT BECOMES MORE ZONAL. && .AVIATION /09Z-06Z/... CURRENTLY THE MAJORITY OF OUR AREA IS VFR UNDER CLEAR SKIES AND GOOD VSBYS, IN BETWEEN CI TO OUR S/SE AND AC TO OUR W/NW. THE AC HAS MOVED INTO THE LEHIGH VALLEY AND WILL CONTINUE TO PUSH SLOWLY E THROUGH THE MORNING HOURS. AS THE FRONTAL ZONE MOVES IN, CIGS WILL LOWER TO SC AND WE MAY EVEN HAVE SOME MVFR CONDITIONS IN LATE DAY SHOWERS. && .MARINE... WINDS HAVE DROPPED OFF BUT SEAS ARE STILL QUITE HIGH. THEY`RE ACTUALLY RUNNING AT OR SLIGHTLY HIGHER THAN WAVEWATCH. WITH THIS IN MIND, WE WILL SEE THE WAVE HEIGHTS LOWER TODAY BUT PROBABLY NOT BELOW SMALL CRAFT ADVISORY CRITERIA BEFORE THE FRONTAL ZONE CROSSES THE AREA AND WINDS PICK UP FROM A WNW DIRECTION. EXPECT GUSTS TO AROUND 25 KT TONIGHT AND SUNDAY. WILL CARRY THE SCA THROUGH SUNDAY FOR NOW. THEY MIGHT EVEN GO INTO SUNDAY NIGHT, BUT SINCE THATS THE 4TH PERIOD, I WON`T GO THERE. && .HYDROLOGY... THE BULK OF THE FLOODING HAS ALREADY OCCURRED HOWEVER SEVERAL SPOTS OF FLOODING ARE ONGOING. PLEASE CHECK THE LATEST FLOOD WARNINGS /FLWPHI/ AND FLOOD STATEMENTS /FLSPHI/ FOR THE LATEST INFORMATION. PLEASE USE EXTREME CAUTION AROUND CREEKS AND STREAMS AS THE WATER FLOW HAS BEEN ENHANCED DUE TO ALL THE RUNOFF. ALL WATERWAYS WILL BE CLOSELY MONITORED AS THEY CREST AND ALSO ANY OTHER POSSIBLE RISES TAKE PLACE. NO ADDITIONAL SIGNIFICANT PRECIPITATION IS EXPECTED THROUGH EARLY NEXT WEEK. && $$ SYNOPSIS... SHORT TERM...SZATKOWSKI LONG TERM...SZATKOWSKI AVIATION...RPW MARINE...RPW HYDROLOGY...RPW/SZATKOWSKI
AREA FORECAST DISCUSSION
NWS BALTIMORE MD/WASHINGTON DC
905 AM EST SAT MAR 3 2007 .SHORT TERM... WATER VAPOR LOOP SHOWS A POSITIVELY TILTED TROUGH ELONGATING FROM QUEBEC SOUTHWEST THROUGH THE PLAINS. ACARS 400-250MB WIND OBSERVATIONS REVEAL A 150-195KT SOUTHWESTERLY JET FROM THE PLAINS THROUGH THE MID ATLANTIC. 11Z SURFACE ANALYSIS PLACED A 993MB CYCLONE ACROSS THE UPPER GREAT LAKES. A SERIES OF COLD FRONTS EXTEND FROM THE LOW TO THE SOUTH-SOUTHWEST. THE FIRST WAS DISSIPATING ACROSS THE APPALACHIANS...WITH THE SECOND COLD FRONT STRETCHED THROUGH INDIANAPOLIS AND SOUTHERN MISSOURI...AND THE THIRD WAS ENTERING NORTHWEST ILLINOIS TO NORTHERN KANSAS. LAPSE RATES STEEPEN THROUGHOUT THE DAY WITH THE APPROACH OF THE MID LEVEL TROUGH. IMPULSES EMBEDDED WITHIN THE TROUGH ALOFT MAY FORCE SCATTERED SHOWER AND THUNDERSTORM DEVELOPMENT BY MID AFTERNOON (06Z NAM/GFS INDICATE 100-200 J/KG OF INSTABILITY DURING THE AFTERNOON). EVAPORATIVE COOLING ASSOCIATED WITH THE INVERTED-V SOUNDING (DOWNDRAFT TEMPERATURES NEAR 45F) SHOULD PROVIDE A FAVORABLE ENVIRONMENT FOR HIGHER WIND GUSTS WITHIN CONVECTIVE ELEMENTS. SMALL HAIL WILL BE POSSIBLE...ESPECIALLY ACROSS THE NORTHWEST FORECAST AREA WHERE EQUILIBRIUM LEVEL TEMPERATURES DROP TO -25C. MIXING THE SHALLOW (BUT STEEP) NOCTURNAL INVERSION SHOULD YIELD 60-65F ACROSS THE SOUTHEAST FORECAST AREA. KEPT THE NORTHWEST FORECAST AREA COOLER TO ACCOUNT FOR EARLIER ARRIVAL OF CLOUDS AND COLD ADVECTION WITH THE COLD FRONTAL PASSAGE BY LATE AFTERNOON. SOUTHWEST WINDS WILL BE BREEZY AHEAD OF THE COLD FRONT. && .HYDROLOGY... EXPECT MAIN STEM RIVERS TO CONTINUE TO CREST...WITH ALL FORECAST POINTS BELOW FLOOD STAGE BY LATE AFTERNOON. && .AVIATION... GRADIENT TIGHTENS AHEAD OF THE NEXT SECONDARY COLD FRONT THIS AFTERNOON. STEEPENING LAPSE RATES MAY SUPPORT ISOLATED TO SCATTERED SHOWER AND THUNDERSTORM ACTIVITY FROM MID AFTERNOON INTO THE EVENING. && .MARINE... 00Z ETA/06 GFS MOS AT THOMAS POINT INDICATE SUSTAINED WINDS WILL INCREASE TO NEAR 15KT THIS AFTERNOON. 06Z NAM/GFS PROXIMITY FORECAST SOUNDINGS INDICATE WIND GUST POTENTIAL OF 25-30 KNOTS THIS AFTERNOON AND TONIGHT. AFTERNOON SCATTERED SHOWER AND THUNDERSTORMS MAY CONTAIN LOCALLY HIGHER WIND GUSTS. MARINERS SHOULD MONITOR FOR LATER FORECASTS. && .TIDES... CURRENT TIDAL DEPARTURES ARE A HALF TO ONE FOOT ABOVE ASTRONOMICAL PREDICTIONS. THE LUNAR CYCLE IS AT A FULL MOON (100 PERCENT FULL). THE CHESAPEAKE BAY OPERATIONAL FORECAST SYSTEM INDICATES WATER LEVELS WILL BE LEVEL OR GRADUALLY RECEDE CLOSER TO ASTRONOMICAL PREDICTIONS THROUGH EARLY TONIGHT. && .LWX WATCHES/WARNINGS/ADVISORIES... DC...NONE. MD...NONE. VA...NONE. WV...NONE. MARINE...SMALL CRAFT ADVISORY FROM 12 PM SATURDAY TO 5 AM EST SUNDAY FOR ANZ530>537. && $$ SHORT TERM/HYDROLOGY/AVIATION/MARINE/TIDES...ROGOWSKI
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1015 AM EST SAT MAR 3 2007 .UPDATE... 12Z RAOBS/WV IMAGERY AND RUC ANALYSIS SHOW WEAKENING OCCLUSION OVER NRN LK HURON SLIPPING SLOWLY TO THE E WITH CONSIDERABLE 00Z-12Z H5 HGT RISES NOTED TO THE W (110M AT MPX) IN THE WAKE OF THIS MAJOR WINTER STORM. AS A RESULT...MUCH DRIER MID LVL AIR/LOWER INVRN HGT JUST BLO H9 AS SHOWN ON THE 12Z INL/YPL RAOBS IS BEGINNING TO ADVANCE INTO WRN LK SUP AND THE FAR WRN CWA. VSBY AT IWD HAS RISEN QUICKLY THIS MRNG WITH APRNT ARRIVAL OF THE LOWER INVRN. WIND SPEEDS BEGINNING TO DCRS OVER WRN LK SUP AS WELL WITH DCRS IN MIXING DEPTH EVEN THOUGH PRES GRADIENT REMAINS RATHER SHARP. FARTHER E...HEAVIER SHSN CONT OVER THE NCNTRL WHERE AXIS OF DEEPER MSTR APRNT ON STLT IMAGERY ENHANCING LES IN CYC N FLOW. 12Z GRB SDNG INDICATES DEEP MSTR EXTENDS TO H3 WITHIN THIS AXIS OF DEEPER MSTR. MAIN FCST CONCERNS IN THE SHORT TERM REVOLVE ARND LES TRENDS/AMTS/ WINDS/GOING HEADLINES. LATEST RUC IS SLOWER AT MOVING DEEPER MSTR TO THE E THAN THE LATEST NAM BECAUSE THAT MODEL SHOWS A REINFORCING SHRTWV OVER NW ONTARIO DROPPING S (REFLECTED IN 20M 00Z-12Z H HGT FALL AT YPL) ON THE BACK SIDE OF PARENT OCCLUDED LO AND MAINTAINING HIER MID LVL MSTR/ SUBSIDENCE INVRN BASE. HOWEVER...RUC SHOWS LARGER SCALE DEEP LYR QVECTOR DVGC/SUBSIDENCE...INDICATING THAT DRY ADVCTN WL OVERCOME THE PVA. FAVOR FASTER NAM PER STLT/OBSVD TRENDS. ALL IN ALL...GOING FCST HAS OBSVD/EXPECTED TRENDS IN HAND. MAINTAINED HEADLINE ENDING TIMES BY EARLY AFTN OVER THE W AND EARLY EVNG IN MQT/ALGER COUNTIES. MINOR CHGS MADE INCLUDE INCRSG COVG OF SHSN OVER NRN DELTA COUNTY/A BIT MORE SN INTO EARLY AFTN TO ACCOUNT FOR LATEST RADAR IMAGERY SHOWING HEAVIER BANDS MOVING INTO THE NRN PART OF THAT COUNTY. ALSO TENDED TO DIMINISH WINDS FASTER OVER THE W HALF OF LK SUP WITH ARRIVAL OF LOWER INVRN/REDUCED MIXING DEPTH. KC .PREVIOUS DISCUSSION (ISSUED AT 435 AM)... MAIN FCST ISSUES ARE FATE OF ONGOING HEADLINES AND TIMING THE END OF SNOW AS DECAYING STORM SYSTEM OVER THE GREAT LAKES HEADS E. WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW MIDLEVEL LOW CONTINUING TO FILL AS IT TRACKS E ACROSS NRN LWR MI EARLY THIS MORNING. MOISTURE WRAPPING AROUND THE SYSTEM STILL ENCOMPASSES UPPER MI/LAKE SUPERIOR. DEEP MOISTURE/CYCLONIC FLOW COMBINED WITH 850MB TEMPS RANGING FROM ABOUT -14C SCNTRL LAKE SUPERIOR TO -16C WRN LAKE SUPERIOR PER 06Z RUC ANALYSIS IS RESULTING IN LAKE ENHANCED SNOW IN N WIND FAVORED LOCATIONS. 850MB TEMPS ARE PROBABLY LOWER THAN RUC ANALYSIS OVER THE W AS 05Z TAMDAR SOUNDING FROM CYQT SHOWED 850MB TEMP OF -19C. IT ALSO APPEARS 850MB TEMPS HAVE DROPPED A BIT MORE RECENTLY OVER CNTRL LAKE SUPERIOR AS LES BANDS ARE BEGINNING TO FORM IN WHAT HAD BEEN AN AREA OF SNOW WITH LITTLE STRUCTURE/ORGANIZATION. KDLH RADAR HAS OCCASIONALLY SHOWED BANDS STREAMING INTO FAR WRN UPPER MI NEAR KIWD...SO DECENT SNOW HAS BEEN OCCURRING IN THAT AREA OVERNIGHT. HAD A REPORT JUST AFTER MIDNIGHT OF MDT TO HVY SNOW ON THE KEWEENAW IN THE PHOENIX/DELAWARE AREAS. SNOW OVERNIGHT HAS HAD A HIGH SNOW TO WATER RATIO AS EXPECTED DUE TO 7-10KFT LAYER OF FAVORABLE DENDRITIC SNOW GROWTH TEMPS IN THE MOIST LAYER. MODELS ARE IN GOOD AGREEMENT TAKING MIDLEVEL LOW TO SRN QUEBEC BY 00Z SUN...AND NAM/GFS ARE NOW ALSO IN GOOD AGREEMENT BRINGING BACK EDGE OF DEEP MOISTURE W TO E ACROSS THE FCST AREA TODAY/TONIGHT. IT SHOULD REACH THE WRN FCST AREA LATE MORNING/EARLY AFTN AND CLEAR THE FAR ERN FCST AREA MID/LATE EVENING. AT THE SAME TIME...CYCLONIC FLOW WILL RELAX AND BECOME NEUTRAL THEN ANTICYCLONIC FROM W TO E. EVEN THOUGH 850MB TEMPS WILL RANGE FROM -13C TO -16C TO SUPPORT LES THRU THE DAY...DEPARTURE OF DEEP MOISTURE WILL RESULT IN A SHARP DIMINISHING TREND BEFORE SHSN END W THIS EVENING AND E LATE TONIGHT. WITH EXPECTED FLUFFY ACCUMULATIONS OF 1 TO 3 INCHES W AND 1 TO 4 INCHES NCNTRL TODAY...WILL NEED TO EXTEND HEADLINES EVEN THOUGH A FEW INCHES OF THIS LOW WATER CONTENT SNOW WILL REALLY NOT BE MUCH MORE THAN A NUISANCE COMPARED TO WHAT THE AREA EXPERIENCED THU NIGHT/FRI. PERIOD OF MOSTLY CLEAR/PARTLY CLOUDY SKIES WILL FOLLOW FROM W TO E TONIGHT/SUN MORNING. RIBBON OF ISENTROPIC ASCENT (290K SFC) ASSOCIATED WITH A WEAK SHORTWAVE DIVING SE TOWARD THE UPPER LAKES WILL PASS ACROSS THE AREA LATE TONIGHT THRU EARLY SUN AFTN. EVEN SO...IT LOOKS LIKE A GOOD PORTION OF THE NIGHT WILL BE MOSTLY CLEAR/PARTLY CLOUDY OVER ROUGHLY THE W HALF OF FCST AREA. THIS SHOULD ALLOW FOR DECENT RADIATIONAL COOLING AS WEAK SFC RIDGE PASSES. HAVE THUS FAVORED THE LOWER SIDE OF MOS GUIDANCE OVER THE INTERIOR W. CLOUDS WILL LINGER THRU MOST IF NOT ALL OF THE NIGHT OVER THE FAR E...KEEPING MINS HIGHER THERE THAN OVER THE W. RIBBON OF MID/HIGH CLOUDS WILL PROGRESS ACROSS THE AREA SUN...AND IT APPEARS TO BE FOLLOWED BY A LOWER STRATOCU DECK PER GFS/NAM RH PROGS. LOW-LEVEL ISENTROPIC ASCENT WITH LOW CONDENSATION PRES DEFICITS ON THE 275K SFC (ROUGHLY AROUND 900MB) SUPPORTS THE IDEA OF SCT/BKN LOWER CLOUDS SWEEPING INTO THE AREA SUN AFTN/EVENING. THESE CLOUDS WILL BE AHEAD OF A STRONGER SHORTWAVE HEADING SE INTO ONTARIO. PRES GRADIENT TIGHTENS AHEAD OF FEATURE WITH NAM/GFS SHOWING WRLY 950MB WINDS RAMPING UP TO 35 TO 40KT SUN AFTN/EVENING AHEAD OF APPROACHING ARCTIC FRONT...SUPPORTING POTENTIAL OF GALES ON LAKE SUPERIOR. REGARDING SHORTWAVE...NAM IS QUITE A BIT STRONGER WITH FEATURE THAN GFS/UKMET/CANADIAN...AND IT IS ABOUT 6 HRS SLOWER WITH FROPA. SEE NO REASON NOT TO FOLLOW BULK OF GUIDANCE WITH REGARD TO DETAILS. WRLY GALES AHEAD OF FRONT WILL SHIFT TO A PERIOD OF NW GALES AFTER FROPA SUN NIGHT UNDER STRONG CAA REGIME (850MB TEMPS FALL FROM AROUND -10C SUN EVENING TO AROUND -20C BY MON MORNING). WITH 850MB TEMPS TOO HIGH TO SUPPORT LES PRIOR TO FROPA...NOT REALLY EXPECTING A SIGNIFICANT BAND OF SNOW ALONG ARCTIC FRONT AS IT PASSES. IN ADDITION...BULK OF FORCING WITH SHORTWAVE PASSES NE OF FCST AREA. AT THIS POINT...CHC POPS LOOK FINE WITH FROPA SUN NIGHT. HEALTHY SUBSIDENCE/DRY AIR AND INVERSION SETTLING TO AROUND 4KFT ON MON SUGGEST LES WILL BE ON THE LIGHT SIDE DESPITE 850MB TEMPS IN THE -20 TO -23C RANGE. ARCTIC HIGH PRES RIDGE BUILDS SE OVER THE UPPER LAKES/ONTARIO MON NIGHT...SETTING UP WHAT WOULD APPEAR TO BE A VERY COLD NIGHT OVER THE INTERIOR W AND CNTRL FCST AREA. HOWEVER...MODELS ARE FAIRLY AGGRESSIVE IN SPREADING CONSIDERABLE MID/HIGH LEVEL MOISTURE INTO THE AREA DOWNSTREAM OF DEVELOPING WAA PATTERN OVER THE NRN PLAINS/UPPER MISSISSIPPI VALLEY. NOT SURE HOW LONG THE WINDOW WILL BE FOR RADIATIONAL COOLING...BUT WILL TAKE A CONSERVATIVE APPROACH ON TEMP DROP MON NIGHT...GOING A FEW DEGREES ABOVE LATEST GFS MOS GUIDANCE. SHOULD BULK OF NIGHT END UP CLEAR...TEMPS WOULD LIKELY FALL TO -15F IN THE TYPICAL COLD SPOTS. BEYOND MON NIGHT...REST OF NEXT WEEK SHOWS PLENTY OF UNCERTAINTY WITH A SERIES OF SHORTWAVES RUNNING ALONG BOUNDARY BTWN ARCTIC AIR IN CANADA AND MILD AIR COVERING MUCH OF THE CNTRL CONUS. FIRST OF THESE WILL ARRIVE TUE...AND GOING FCST HAS THIS COVERED WELL WITH -SN CHC POPS. NO CHANGES NEEDED BEYOND TUE. ROLFSON && .MQT WATCHES/WARNINGS/ADVISORIES... WINTER STORM WARNING UNTIL 18Z TODAY MIZ002-004-009. WINTER STORM WARNING UNTIL 23Z TODAY MIZ005. SNOW AND BLOWING SNOW ADVY UNTIL 18Z TODAY MIZ001-003. SNOW AND BLOWING SNOW ADVY UNTIL 23Z TODAY MIZ006. GALE WARNING LAKE SUPERIOR. && $$
AREA FORECAST DISCUSSION
NWS SEATTLE WA
245 AM PST SAT MAR 3 2007 .SYNOPSIS...LIGHT RAIN WILL BEGIN DECREASING THIS MORNING AS A WEAK FRONT MOVES EAST OF THE AREA. A WEAK UPPER LEVEL RIDGE WILL PRODUCE MOSTLY DRY BUT CLOUDY WEATHER TONIGHT. THE RIDGE WILL MOVE EAST TONIGHT AND INCREASING SOUTHWEST FLOW ALOFT WILL ALLOW A SERIES OF WEATHER SYSTEMS TO REACH THE REGION THROUGH LATE NEXT WEEK. A STRONG COLD FRONT WILL APPROACH THE AREA MONDAY NIGHT AND MOVE THROUGH LATE TUESDAY. && .SHORT TERM...A WEAK WARM FRONT IS SOMEWHERE OVER THE AREA THIS MORNING BUT NO REAL SURFACE BOUNDARY IS EVIDENT ON SATELLITE OR IN OBS. MOST SIGNIFICANT POINT IS THAT THE VERY MOIST AIR MASS WILL CONTINUE OVER THE AREA TODAY...WITH UPWARD MOTION ENDING THIS MORNING AS WHATEVER IS LEFT OF THE WARM FRONT DISSIPATES OR MOVES EAST. THUS KEPT THE LIKELY POPS FOR THIS MORNING...A LITTLE HIGHER THAN MOS GUIDANCE AND STAYED WITH CHANCE POPS THIS AFTERNOON. SURFACE GRADIENTS WILL ALSO WEAKEN TODAY SO WE`RE STUCK WITH THE LOW LEVEL MOISTURE TONIGHT. ANY LOSS IN CLOUD COVER OVERNIGHT WILL HELP FOG FORM. CASCADES...ACARS SOUNDINGS AROUND MIDNIGHT SHOWED A FREEZING LEVEL 6500-7000 FEET...BUT OBS SHOW THE PASSES ARE STILL SUB-FREEZING IN EASTERLY FLOW AND STILL RECEIVING A LITTLE LIGHT SNOW...THOUGH NO REAL INCREASE IN SNOW DEPTH. PROBABLY A LITTLE FREEZING RAIN IS OCCURRING NOT TOO FAR WEST OF THE PASSES. WILL HANG ON TO THE WINTER WEATHER ADVISORY FOR THE CASCADES THROUGH 10 AM AS PLANNED. ADVISORY SHOULD BE EXPIRING ABOUT WHEN THE PRECIP REALLY TAPERS OFF. GFS/NAM DIFFERED IN THE 00Z RUNS FOR TONIGHT...WITH GFS PUTTING QPF OVER THE AREA...CAUSED BY A WEAK VORT MAX EMBEDDED IN THE SW FLOW ON THE UPSTREAM SIDE OF THE UPPER LEVEL RIDGE. 06Z GFS HAS SINCE MIGRATED CLOSER TO THE DRIER NAM SOLUTION. ELECTED TO STAY WITH THE DRY FORECAST TONIGHT...THOUGH MOS POPS ARE 15-20 PERCENT. THE UPPER LEVEL RIDGE AXIS IS OVER MONTANA BY SUNDAY AFTERNOON WITH GRADUALLY INCREASING SW FLOW ALOFT OVER WESTERN WA. BOTH NAM/GFS HAVE A SMALL WEAK SHORT-WAVE TROUGH APPROACHING THE COAST IN THE AFTERNOON. AIR MASS REMAINS MOIST...SO EVEN THE WEAK UPWARD MOTION GENERATED BY THIS WAVE SHOULD BE ENOUGH TO WRING OUT SOME LIGHT RAIN...CHANCE POPS FINE FOR NOW. ANOTHER WEAK SHORT-WAVE IN THE SERIES DOES THE SAME THING ON MONDAY. .LONG TERM...NEXT SIGNIFICANT SYSTEM SHOULD BE A STRONG COLD FRONT...APPROACHING MONDAY NIGHT AND HEADING EAST LATE TUESDAY. GFS/ECMWF/NAM ALL HAVE SOMEWHAT SIMILAR STRENGTH AND TIMING...JUST DIFFERENT HANDLES ON THE SURFACE LOW HEADING TOWARD VANCOUVER ISLAND. SIGNIFICANT EFFECT FROM ALL SOLUTIONS IS THE INCREASING SE GRADIENT FOR WINDY IN THE TYPICAL SE EXPOSED AREAS. SHOWERY... COOLER...SNOW LEVEL-BELOW-THE-PASSES WEATHER SHOULD ENSUE AFTER THE COLD FRONT TUESDAY NIGHT...AS A NICE BIG UPPER LEVEL TROUGH SETS UP OFFSHORE AND LASTS THROUGH AT LEAST THURSDAY. KAM && .AVIATION...MOIST AIR MASS IN THE LOW LEVELS THROUGH THIS EVENING. THE WARM FRONT EASES NE AND RAIN CHANGES TO DRIZZLE...AND AS THE MID LEVEL DRIES UP JUST LOW STRATUS IS LEFT BEHIND. SO...EXPECTING LITTLE IMPROVEMENT TODAY EVEN AS 1030MB SFC HIGH BUILDS OVER THE SW PART OF WA BY 00Z. FOR THAT MATTER...I AM NOT SURE THAT ENOUGH OFFSHORE FLOW WILL DRYING THINGS OUT TONIGHT SO FOG MAY DEVELOP EVEN AS STRATUS FINALLY DRIES UP TONIGHT. $$ .SEW WATCHES/WARNINGS/ADVISORIES... .WINTER WEATHER ADVISORY NORTH AND CENTRAL CASCADES THROUGH 10 AM SAT. .SMALL CRAFT ADVISORY FOR ROUGH BAR CONDITIONS ON THE GRAYS HARBOR BAR. $$ WEATHER.GOV/SEATTLE