Forecast Discussions mentioning "ACARS", "MDCRS", "AIRCRAFT", "TAMDAR", or "AMDAR" received at FSL on 01/18/07

.SYNOPSIS...WEAKENING OFFSHORE FLOW WILL CONTINUE LOCAL GUSTY WINDS THIS EVENING...MAINLY THROUGH AND BELOW MOUNTAIN CANYONS AND PASSES. OTHERWISE...FAIR THROUGH WEDNESDAY. UPPER LEVEL LOW PRESSURE WILL BRING PARTLY CLOUDY SKIES WITH A SLIGHT CHANCE OF SHOWERS IN SAN DIEGO COUNTY LATE WEDNESDAY THROUGH THURSDAY. PERIODS OF OFFSHORE FLOW WILL PREVAIL LATE THURSDAY THROUGH THE MIDDLE OF NEXT WEEK FOR DRY WEATHER AND LOCAL GUSTY WINDS. GRADUALLY WARMER DAYS AND NOT AS COLD AT NIGHT.

&&

.DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE... SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO COUNTIES...

.SHORT TERM (TODAY-FRI)...CLEAR SKIES TODAY. ACARS SOUNDINGS HAD NE WINDS TO 20 KTS IN THE LOW LEVELS AND WLY WINDS ALOFT. WEAKENING OFFSHORE GRADIENTS WITH ABOUT -5 MB SAN-IPL.

LOCAL GUSTY WINDS WILL CONTINUE THROUGH AND BELOW MOUNTAIN CANYONS AND PASSES THIS EVENING BUT THEY SHOULD REMAIN BELOW ADVISORY STRENGTH. SUPPORT FOR THE OFFSHORE FLOW WILL WEAKEN FURTHER LATER TONIGHT WITH DECREASING WINDS. CURRENT INDICATIONS ARE THAT AN UPPER LOW WILL DROP S JUST OFF THE COAST BY LATE WED NIGHT AND THEN MOVE INLAND TO THE S OF SAN DIEGO THU AND INTO AZ BY FRI. HOWEVER...MODELS HAVE BEEN INCONSISTENT WITH THIS SYSTEM AND A SMALL CHANGE IN THE EXACT PATH OF THIS LOW WILL MAKE A BIG DIFFERENCE IN THE LOCAL WEATHER. WILL KEEP SLIGHT CHANCE OF PRECIP CONFINED TO SAN DIEGO COUNTY LATE WED THROUGH THU FOR NOW. OFFSHORE FLOW WILL DEVELOP ON THE W SIDE OF THIS LOW LATE THU AND FRI AND COULD POTENTIALLY BE STRONG. WILL ONLY INDICATE MODERATE OFFSHORE WINDS AT THIS TIME DUE TO LARGE UNCERTAINTIES IN THE FORECAST TRACK OF THE LOW. A LITTLE WARMER DAYS IN MOST AREAS...ESPECIALLY W OF THE MOUNTAINS ON FRI. NOT QUITE AS COLD TONIGHT BUT THERE WILL STILL BE AREAS OF FROST BY MORNING WITH EXCELLENT RADIATIONAL COOLING CONDITIONS UNDER CLEAR SKIES WITH LOW DEW POINTS. WARMER WED NIGHT AND THEN SLIGHTLY COOLER THU NIGHT.

.LONG TERM (FRI-TUE)...PERIODS OF OFFSHORE FLOW SHOULD PREVAIL FOR DRY WEATHER AND LOCAL GUSTY WINDS AT TIMES...MAINLY THROUGH AND BELOW MOUNTAIN CANYONS AND PASSES. GRADUALLY WARMER DAYS. COOL AT NIGHT IN AREAS PROTECTED FROM THE WINDS. THE EXTENDED PERIOD OF DRY OFFSHORE FLOW WILL INCREASE THE FIRE WEATHER HAZARD ONCE AGAIN. THERE MAY ALSO BE PERIODS OF WINDS STRONG ENOUGH FOR LOCAL WIND ADVISORIES OR WARNINGS. &&

.AVIATION... DECREASING OFFSHORE FLOW WILL CONTINUE CLEAR SKIES AND UNRESTRICTED VSBYS THIS AFTERNOON AND EVENING. ONSHORE FLOW WILL RETURN WEDNESDAY MORNING AND UPPER LEVEL LOW PRESSURE APPROACHING FROM THE NORTH WILL BRING SOME CLOUDS AND A SLIGHT CHANCE OF SHOWERS BY WEDNESDAY AFTERNOON. WINDS AT 10K FT WILL BACK TO THE SOUTHWEST AND INCREASE TO 25-35 KT WEDNESDAY AS WELL. OFFSHORE FLOW WILL LIKELY MAKE A RETURN THURSDAY.

&&

.SGX WATCHES/WARNINGS/ADVISORIES...

RED FLAG WARNING UNTIL 6 PM THIS EVENING FOR...ALL MOUNTAINS AND INLAND VALLEY AREAS AND ORANGE COUNTY COASTAL AREA. SEE LAXRFWSGX.

$$

PUBLIC...DVA AVIATION...SCV

.SYNOPSIS...WEAKENING OFFSHORE FLOW WILL CONTINUE LOCAL GUSTY WINDS THROUGH AND BELOW MOUNTAIN CANYONS AND PASSES TODAY...OTHERWISE FAIR THROUGH WEDNESDAY. UPPER LEVEL LOW PRESSURE WILL BRING PARTLY CLOUDY SKIES WITH A SLIGHT CHANCE OF SHOWERS IN SAN DIEGO COUNTY LATE WEDNESDAY THROUGH THURSDAY. PERIODS OF OFFSHORE FLOW WILL PREVAIL LATE THURSDAY THROUGH THE MIDDLE OF NEXT WEEK FOR DRY WEATHER AND LOCAL GUSTY WINDS. GRADUALLY WARMER DAYS AND NOT AS COLD AT NIGHT.

&&

.DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE... SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO COUNTIES...

.SHORT TERM (TODAY-FRI)...CLEAR SKIES TODAY. ACARS SOUNDINGS HAD NE WINDS TO 20 KTS IN THE LOW LEVELS AND WLY WINDS ALOFT. OFFSHORE GRADIENTS WITH ABOUT -9 MB SAN-IPL.

LOCAL GUSTY WINDS WILL CONTINUE THROUGH AND BELOW MOUNTAIN CANYONS AND PASSES TODAY AND THE CURRENT WIND WARNINGS AND ADVISORIES LOOK OK. THE DRY OFFSHORE FLOW WILL MAINTAIN AN ELEVATED FIRE WEATHER HAZARD THROUGH THIS AFTERNOON. SUPPORT FOR OFFSHORE FLOW WILL WEAKEN THIS AFTERNOON AND TONIGHT. CURRENT INDICATIONS ARE THAT AN UPPER LOW WILL DROP S JUST OFF THE COAST BY LATE WED NIGHT AND THEN MOVE INLAND TO THE S OF SAN DIEGO THU AND INTO AZ BY FRI. HOWEVER...MODELS HAVE BEEN INCONSISTENT WITH THIS SYSTEM AND A SMALL CHANGE IN THE EXACT PATH OF THIS LOW WILL MAKE A BIG DIFFERENCE IN THE LOCAL WEATHER. WILL KEEP SLIGHT CHANCE OF PRECIP CONFINED TO SAN DIEGO COUNTY LATE WED THROUGH THU FOR NOW. OFFSHORE FLOW WILL DEVELOP ON THE W SIDE OF THIS LOW LATE THU AND FRI AND COULD POTENTIALLY BE STRONG. WILL ONLY INDICATE MODERATE OFFSHORE WINDS AT THIS TIME DUE TO LARGE UNCERTAINTIES IN THE FORECAST TRACK OF THE LOW. A LITTLE WARMER DAYS IN MOST AREAS...ESPECIALLY W OF THE MOUNTAINS ON FRI.

.LONG TERM (FRI-TUE)...PERIODS OF OFFSHORE FLOW SHOULD PREVAIL FOR DRY WEATHER AND LOCAL GUSTY WINDS AT TIMES...MAINLY THROUGH AND BELOW MOUNTAIN CANYONS AND PASSES. GRADUALLY WARMER DAYS. COOL AT NIGHT IN AREAS PROTECTED FROM THE WINDS. THE EXTENDED PERIOD OF DRY OFFSHORE FLOW WILL INCREASE THE FIRE WEATHER HAZARD ONCE AGAIN. THERE MAY ALSO BE PERIODS OF WINDS STRONG ENOUGH FOR LOCAL WIND ADVISORIES OR WARNINGS. &&

.AVIATION... GUSTY OFFSHORE WINDS WILL CONTINUE TODAY NEAR AND BELOW THE MOUNTAIN PASSES AND CANYONS...THEN WEAKEN THIS AFTN INTO WED. THE STRONGEST WINDS WILL OCCUR THIS MORNING BELOW THE CAJON PASS IN THE INLAND EMPIRE AND NEAR THE SANTA ANA MOUNTAINS. THESE WINDS WILL GENERATE AREAS OF TURBULENCE...STRONG UP AND DOWN DRAFTS...MOUNTAIN WAVES WITH ROTORS AND LOCAL LOW LEVEL WIND SHEAR. LOCAL BLOWING DUST COULD ALSO OCCUR AT TIMES. OTHERWISE VFR CONDITIONS WILL PREVAIL WITH CLEAR SKIES AND UNRESTRICTED VSBYS. WINDS AT 10K FT WILL SHIFT WESTERLY ON WEDNESDAY AND INCREASE TO 25-35 KT AS AN UPPER LEVEL LOW APPROACHES THE AREA.

&&

.SGX WATCHES/WARNINGS/ADVISORIES...

HIGH WIND WARNING UNTIL 3 PM THIS AFTERNOON FOR...THE INLAND EMPIRE...SAN BERNARDINO MOUNTAINS AND SANTA ANA MOUNTAINS. SEE LAXNPWSGX.

WIND ADVISORY UNTIL 3 PM THIS AFTERNOON FOR...ORANGE COUNTY COASTAL AREAS...SAN DIEGO COUNTY VALLEYS...RIVERSIDE COUNTY MOUNTAINS AND SAN DIEGO COUNTY MOUNTAINS. SEE LAXNPWSGX.

RED FLAG WARNING UNTIL 6 PM THIS EVENING FOR...ALL MOUNTAINS AND INLAND VALLEY AREAS AND ORANGE COUNTY COASTAL AREA. SEE LAXRFWSGX.

$$

PUBLIC...DVA AVIATION...SCV

.UPDATE... THROUGH 930 PM EST TEMPERATURES REMAIN ABOVE FREEZING AS A MIXTURE OF RAIN AND SLEET DRIFTS ACROSS THE AREA. THIS PRECIPITATION SHOULD BE TAPERING OFF FROM THE WEST OVER THE NEXT SEVERAL HOURS OVER THE WESTERN PART OF THE STATE. HOWEVER...AN EARLY LOOK AT THE 00Z MODELS CONTINUES TO SUGGEST A COASTAL LOW FORMING THAT WILL PRODUCE ADDITIONAL PRECIP OVER THE EASTERN PART OF THE STATE. IF THAT HAPPENS...TEMPERATURES OVER MUCH OF NORTHEAST GEORGIA AND PORTIONS OF EAST CENTRAL GEORGIA WILL DROP TO THE FREEZING MARK OR EVEN LOWER BASED ON WET BULB VALUES. AS THIS THREAT REMAINS...THE WINTER WEATHER ADVISORY WILL BE LEFT IN PLACE AT THIS TIME.

SITUATION CONTINUES TO EVOLVE ABOUT AS ANTICIPATED...SO NO CHANGES IN THE FORECAST ARE PLANNED. &&

(PREVIOUS DISCUSSION)...

.SHORT TERM... A RATHER COMPLICATED WEATHER SYSTEM WILL MOVE ACROSS THE CWA TONIGHT AND EARLY THURSDAY. THE SURFACE RIDGE WILL CONTINUE NOSING INTO GEORGIA SUPPLYING US WITH LOWER DEWPOINTS AND COLD AIR. THE MODELS ARENT DOING TOO BAD IN HANDLING THE LOWER DEWPOINTS...THE BIG QUESTION IS HOW DRY WILL THE AIR GET BEFORE THE RAIN STARTS MOISTENING THE ATMOSPHERE. THE PRECIP IS JUST ENTERING WESTERN ALABAMA AND SHOULD BE INTO WESTERN GEORGIA LATER THIS EVENING. FORECAST WET BULB TEMPS INDICATE 32 OR LESS ACROSS NORTHEAST AND PARTS OF EAST CENTRAL GA AFTER 06Z. FOR THIS REASON HAVE KEPT THE WINTER WEATHER ADVISORY FOR PARTS OF NORTHEAST GA. DID NOT INCLUDE THE EXTREME NORTH BORDER COUNTIES AS THESE COUNTIES ARE NORTH OF THE RIDGE LINE AND DO NOT EXPECT THE SUBFREEZING AIR TO SURGE ABOVE THE RIDGE. HOWEVER THE REST OF NORTH AND PARTS OF CENTRAL GEORGIA COULD SEE A LITTLE SLEET MIXED IN WITH THE RAIN TONIGHT AND EARLY THURSDAY.

THE SYSTEM PULLS OUT THURSDAY WITH PRECIP ENDING FROM THE WEST. THE UPPER TROUGH WILL DEEPEN A BIT OVER THE NORTHEAST U.S. AND THIS WILL REINFORCE THE COLD AIR ADVECTION OVER THE THE CWA FRIDAY.

.LONG TERM... AFTER A BRIEF BREAK ON SATURDAY...ANOTHER CHANCE OF PRECIPITATION MOVES INTO THE AREA SUNDAY INTO SUNDAY NIGHT. THIS EXITS OUR AREA EARLY MONDAY...AND AT THIS TIME IT APPEARS DRY THROUGH THE REST OF THE WEEK.

.AVIATION...(7PM TONIGHT THROUGH 7PM THURSDAY) CURRENT TAFS ON TRACK WITH EXTENSIVE MID AND HIGH CLOUDS SPREADING EAST OVER THE CWA. RADARS SHOW AN AREA OF LIGHT RAIN OR SLEET FROM CSG-FFC-MCN MOVING EAST AT 20KTS. SAME TYPE PRECIPITATION OVER CENTRAL ALABAMA WILL MOVE EAST OVER GEORGIA TONIGHT WHILE A LOW PRESSURE SYSTEM DEVELOPS OFF THE GEORGIA COAST. AS THIS OCCURS RIDGING HIGH PRESSURE WILL FORCE ENOUGH COLD AND DRIER AIR NEAR THE SURFACE OVER THE NORTH THIRD OF GEORGIA FOR FREEZING RAIN OR SLEET. SURFACE TEMPERATURES WILL BE CRITICAL FOR ICE ACCUMULATION. EXPECT METAL SURFACES OF AIRCRAFT TO HAVE POTENTIAL ICING PROBLEMS AT THE TERMINALS AND ON THE TAXIWAYS FROM 4AM TO 9AM AROUND MIN TEMPERATURE TIME. THE LIGHT PRECIPITATION WILL GRADUALLY DIMINISH AND MOVE EAST THURSDAY WITH A SLOW TEMPERATURE RISE. IFR CEILINGS WILL SLOWLY RISE TO MVFR DURING THE DAY.

&&

.PRELIMINARY POINT TEMPS/POPS... ATHENS 31 35 33 52 29 / 80 80 5 5 5 ATLANTA 33 39 35 49 29 / 80 60 10 5 5 BLAIRSVILLE 35 39 30 44 23 / 50 50 5 5 5 CARTERSVILLE 33 39 33 47 26 / 60 50 10 5 5 COLUMBUS 36 45 40 54 33 / 80 60 10 5 10 GAINESVILLE 29 35 33 49 28 / 80 70 5 5 5 MACON 34 43 38 55 31 / 80 80 10 10 5 ROME 34 44 33 50 29 / 30 40 10 10 5 PEACHTREE CITY 33 42 35 49 28 / 80 60 10 5 5 VIDALIA 36 45 39 55 35 / 80 60 5 5 5

&&

.FFC WATCHES/WARNINGS/ADVISORIES... WINTER WEATHER ADVISORY FROM MIDNIGHT TONIGHT TO 10 AM EST THURSDAY FOR THE FOLLOWING ZONES: BANKS...BARROW...CLARKE... DAWSON...FORSYTH...GLASCOCK...GREENE...GWINNETT...HALL... HANCOCK...JACKSON...JASPER...LUMPKIN...MADISON...MORGAN... NEWTON...OCONEE...OGLETHORPE...PUTNAM...ROCKDALE...TALIAFERRO... WALTON...WARREN...WHITE...WILKES.

&&

$$

17/16/15

.UPDATE... REPORTS OF SLEET COMING IN FROM CSG TO MCN. THERE APPEARS TO BE A COLD LAYER ALOFT THAT THE MODELS DID NOT PICK UP ON ACROSS CENTRAL GEORGIA. THEREFORE WILL ADD RAIN MIXED WITH SLEET AT TIMES FOR THE REST OF THE CWA. DO NOT EXPECT ANY SLICK ROADS AS TEMPS ARE IN THE 40S AND SHOULD REMAIN ABOVE FREEZING THROUGH THE NIGHT.

&&

.SHORT TERM... A RATHER COMPLICATED WEATHER SYSTEM WILL MOVE ACROSS THE CWA TONIGHT AND EARLY THURSDAY. THE SURFACE RIDGE WILL CONTINUE NOSING INTO GEORGIA SUPPLYING US WITH LOWER DEWPOINTS AND COLD AIR. THE MODELS ARENT DOING TOO BAD IN HANDLING THE LOWER DEWPOINTS...THE BIG QUESTION IS HOW DRY WILL THE AIR GET BEFORE THE RAIN STARTS MOISTENING THE ATMOSPHERE. THE PRECIP IS JUST ENTERING WESTERN ALABAMA AND SHOULD BE INTO WESTERN GEORGIA LATER THIS EVENING. FORECAST WET BULB TEMPS INDICATE 32 OR LESS ACROSS NORTHEAST AND PARTS OF EAST CENTRAL GA AFTER 06Z. FOR THIS REASON HAVE KEPT THE WINTER WEATHER ADVISORY FOR PARTS OF NORTHEAST GA. DID NOT INCLUDE THE EXTREME NORTH BORDER COUNTIES AS THESE COUNTIES ARE NORTH OF THE RIDGE LINE AND DO NOT EXPECT THE SUBFREEZING AIR TO SURGE ABOVE THE RIDGE. HOWEVER THE REST OF NORTH AND PARTS OF CENTRAL GEORGIA COULD SEE A LITTLE SLEET MIXED IN WITH THE RAIN TONIGHT AND EARLY THURSDAY.

THE SYSTEM PULLS OUT THURSDAY WITH PRECIP ENDING FROM THE WEST. THE UPPER TROUGH WILL DEEPEN A BIT OVER THE NORTHEAST U.S. AND THIS WILL REINFORCE THE COLD AIR ADVECTION OVER THE THE CWA FRIDAY.

.LONG TERM... AFTER A BRIEF BREAK ON SATURDAY...ANOTHER CHANCE OF PRECIPITATION MOVES INTO THE AREA SUNDAY INTO SUNDAY NIGHT. THIS EXITS OUR AREA EARLY MONDAY...AND AT THIS TIME IT APPEARS DRY THROUGH THE REST OF THE WEEK.

.AVIATION...(7PM TONIGHT THROUGH 7PM THURSDAY) CURRENT TAFS ON TRACK WITH EXTENSIVE MID AND HIGH CLOUDS SPREADING EAST OVER THE CWA. RADARS SHOW AN AREA OF LIGHT RAIN OR SLEET FROM CSG-FFC-MCN MOVING EAST AT 20KTS. SAME TYPE PRECIPITATION OVER CENTRAL ALABAMA WILL MOVE EAST OVER GEORGIA TONIGHT WHILE A LOW PRESSURE SYSTEM DEVELOPS OFF THE GEORGIA COAST. AS THIS OCCURS RIDGING HIGH PRESSURE WILL FORCE ENOUGH COLD AND DRIER AIR NEAR THE SURFACE OVER THE NORTH THIRD OF GEORGIA FOR FREEZING RAIN OR SLEET. SURFACE TEMPERATURES WILL BE CRITICAL FOR ICE ACCUMULATION. EXPECT METAL SURFACES OF AIRCRAFT TO HAVE POTENTIAL ICING PROBLEMS AT THE TERMINALS AND ON THE TAXIWAYS FROM 4AM TO 9AM AROUND MIN TEMPERATURE TIME. THE LIGHT PRECIPITATION WILL GRADUALLY DIMINISH AND MOVE EAST THURSDAY WITH A SLOW TEMPEERATURE RISE. IFR CEILINGS WILL SLOWLY RISE TO MVFR DURING THE DAY.

&&

.PRELIMINARY POINT TEMPS/POPS... ATHENS 31 35 33 52 29 / 80 80 5 5 5 ATLANTA 33 39 35 49 29 / 80 60 10 5 5 BLAIRSVILLE 35 39 30 44 23 / 50 50 5 5 5 CARTERSVILLE 33 39 33 47 26 / 60 50 10 5 5 COLUMBUS 36 45 40 54 33 / 80 60 10 5 10 GAINESVILLE 29 35 33 49 28 / 80 70 5 5 5 MACON 34 43 38 55 31 / 80 80 10 10 5 ROME 34 44 33 50 29 / 30 40 10 10 5 PEACHTREE CITY 33 42 35 49 28 / 80 60 10 5 5 VIDALIA 36 45 39 55 35 / 80 60 5 5 5

&&

.FFC WATCHES/WARNINGS/ADVISORIES... WINTER WEATHER ADVISORY FROM MIDNIGHT TONIGHT TO 10 AM EST THURSDAY FOR THE FOLLOWING ZONES: BANKS...BARROW...CLARKE... DAWSON...FORSYTH...GLASCOCK...GREENE...GWINNETT...HALL... HANCOCK...JACKSON...JASPER...LUMPKIN...MADISON...MORGAN... NEWTON...OCONEE...OGLETHORPE...PUTNAM...ROCKDALE...TALIAFERRO... WALTON...WARREN...WHITE...WILKES.

&&

$$

17/16

.SHORT TERM... A RATHER COMPLICATED WEATHER SYSTEM WILL MOVE ACROSS THE CWA TONIGHT AND EARLY THURSDAY. THE SURFACE RIDGE WILL CONTINUE NOSING INTO GEORGIA SUPPLYING US WITH LOWER DEWPOINTS AND COLD AIR. THE MODELS ARENT DOING TOO BAD IN HANDLING THE LOWER DEWPOINTS...THE BIG QUESTION IS HOW DRY WILL THE AIR GET BEFORE THE RAIN STARTS MOISTENING THE ATMOSPHERE. THE PRECIP IS JUST ENTERING WESTERN ALABAMA AND SHOULD BE INTO WESTERN GEORGIA LATER THIS EVENING. FORECAST WET BULB TEMPS INDICATE 32 OR LESS ACROSS NORTHEAST AND PARTS OF EAST CENTRAL GA AFTER 06Z. FOR THIS REASON HAVE KEPT THE WINTER WEATHER ADVISORY FOR PARTS OF NORTHEAST GA. DID NOT INCLUDE THE EXTREME NORTH BORDER COUNTIES AS THESE COUNTIES ARE NORTH OF THE RIDGE LINE AND DO NOT EXPECT THE SUBFREEZING AIR TO SURGE ABOVE THE RIDGE. HOWEVER THE REST OF NORTH AND PARTS OF CENTRAL GEORGIA COULD SEE A LITTLE SLEET MIXED IN WITH THE RAIN TONIGHT AND EARLY THURSDAY.

THE SYSTEM PULLS OUT THURSDAY WITH PRECIP ENDING FROM THE WEST. THE UPPER TROUGH WILL DEEPEN A BIT OVER THE NORTHEAST U.S. AND THIS WILL REINFORCE THE COLD AIR ADVECTION OVER THE THE CWA FRIDAY.

.LONG TERM... AFTER A BRIEF BREAK ON SATURDAY...ANOTHER CHANCE OF PRECIPITATION MOVES INTO THE AREA SUNDAY INTO SUNDAY NIGHT. THIS EXITS OUR AREA EARLY MONDAY...AND AT THIS TIME IT APPEARS DRY THROUGH THE REST OF THE WEEK.

.AVIATION...(7PM TONIGHT THROUGH 7PM THURSDAY) CURRENT TAFS ON TRACK WITH EXTENSIVE MID AND HIGH CLOUDS SPREADING EAST OVER THE CWA. RADARS SHOW AN AREA OF LIGHT RAIN OR SLEET FROM CSG-FFC-MCN MOVING EAST AT 20KTS. SAME TYPE PRECIPITATION OVER CENTRAL ALABAMA WILL MOVE EAST OVER GEORGIA TONIGHT WHILE A LOW PRESSURE SYSTEM DEVELOPS OFF THE GEORGIA COAST. AS THIS OCCURS RIDGING HIGH PRESSURE WILL FORCE ENOUGH COLD AND DRIER AIR NEAR THE SURFACE OVER THE NORTH THIRD OF GEORGIA FOR FREEZING RAIN OR SLEET. SURFACE TEMPERATURES WILL BE CRITICAL FOR ICE ACCUMULATION. EXPECT METAL SURFACES OF AIRCRAFT TO HAVE POTENTIAL ICING PROBLEMS AT THE TERMINALS AND ON THE TAXIWAYS FROM 4AM TO 9AM AROUND MIN TEMPERATURE TIME. THE LIGHT PRECIPITATION WILL GRADUALLY DIMINISH AND MOVE EAST THURSDAY WITH A SLOW TEMPEERATURE RISE. IFR CEILINGS WILL SLOWLY RISE TO MVFR DURING THE DAY.

&&

.PRELIMINARY POINT TEMPS/POPS... ATHENS 31 35 33 52 29 / 80 80 5 5 5 ATLANTA 33 39 35 49 29 / 80 60 10 5 5 BLAIRSVILLE 35 39 30 44 23 / 50 50 5 5 5 CARTERSVILLE 33 39 33 47 26 / 60 50 10 5 5 COLUMBUS 36 45 40 54 33 / 80 60 10 5 10 GAINESVILLE 29 35 33 49 28 / 80 70 5 5 5 MACON 34 43 38 55 31 / 80 80 10 10 5 ROME 34 44 33 50 29 / 30 40 10 10 5 PEACHTREE CITY 33 42 35 49 28 / 80 60 10 5 5 VIDALIA 36 45 39 55 35 / 80 60 5 5 5

&&

.FFC WATCHES/WARNINGS/ADVISORIES... WINTER WEATHER ADVISORY FROM MIDNIGHT TONIGHT TO 10 AM EST THURSDAY FOR THE FOLLOWING ZONES: BANKS...BARROW...CLARKE... DAWSON...FORSYTH...GLASCOCK...GREENE...GWINNETT...HALL... HANCOCK...JACKSON...JASPER...LUMPKIN...MADISON...MORGAN... NEWTON...OCONEE...OGLETHORPE...PUTNAM...ROCKDALE...TALIAFERRO... WALTON...WARREN...WHITE...WILKES.

&&

$$

17/16

.DISCUSSION FOR AFTERNOON GRIDS/ZONES...

310 PM CST

LAKE EFFECT SNOW TRENDS MAIN SHORT TERM FOCUS FOR FIRST FEW HOURS TONIGHT.

WEAK VORT/POS TILT UPPER TROF AXIS MOVG EAST OF FCST AREA THIS AFTN. WEAKENING SFC PRES GRADIENT AS SFC HIGH APPRCHG FROM WEST...WITH MODEL TSECTS DEPICTING STRONG AND DEEP SUBSIDENCE DVLPG ATTM. RECENT ACARS SOUNDINGS OUT OF KORD SHOW DIRECTIONAL SHEAR INCREASING THRU ABOUT 750 HPA ALONG WITH DECREASING WIND SPEEDS...AND THIS LACK OF ORGANIZATION RESULTING IN DVLPMNT OF ONE TIME SINGLE BAND LES EVENT NOW TAKING ON MORE OF A THERMALLY FORCED MESO LOW STRUCTURE AS IT FADES. RADAR AND VIS SATELLITE IMGRY FROM LAST HOUR OR SO VERY IMPRESSIVE WITH THIS TRANSITION...LOOKING LIKE A MINI SNOW HURRICANE COMPLETE WITH AN EYE AT 1951Z. IT BEGS TO BE NAMED. WILL HAVE TO CONTEND WITH SNOW SHOWERS ACROSS NORTHERN LAKE/PORTER COUNTIES FOR REMAINDER OF AFTN HOURS AS THIS LES BAND CONTINUES TO DECAY...THOUGH ANTICIPATE THAT COMBINATION OF VERY DRY LOW LVLS...STRENGTHENING AND LOWERING SUBSIDENCE INVERSION AND LOSS OF LLVL CONVERGENCE WILL ALLOW PCPN TO COME TO AN END BY EARLY EVENING.

WITH SFC RIDGE BUILDING ACROSS FCST AREA TNGT...AND SNOW COVER IN PLACE MOST AREAS...SET UP FOR STRONG RADIATIONAL COOLING. LLVL PARCEL TRAJECTORIES FROM NERN IA...WHERE TEMPS DIPPED BLO ZERO THIS MRNG. WILL CONTINUE TO UNDERCUT ALL GUIDANCE NUMBERS FOR MINS OVRNGT...WITH CURRENT GRIDS ACTUALLY LOOKING QUITE GOOD RANGING FROM AROUND -3 NW WHERE DEEPEST SNOW COVER EXISTS...TO NEAR 10 ABOVE SOUTHEAST WHERE SNOW COVER MINIMAL.

MID LVL S/WV RDG MOVS ACROSS FCST AREA WED MORNING...WITH TSECTS AND FCST SOUNDINGS CONTINUING TO DEPICT VERY DRY AMS. SHOULD SEE PLENTY OF SUNSHINE...WITH A LITTLE REBOUND IN TEMPS AS WAA DVLPS IN SWLY FLOW ON BACK SIDE OF SFC RIDGE DURG AFTN. S/WV TROF THEN MOVG OUT OF HIGH PLAINS WED NGT EXPCTD TO GENERATE SOME MID CLOUD COVER AFTER MIDNIGHT AS IT APPROACHES UPPER MS VLY TOWARD MRNG. SWLY LLVL FLOW 10-15 MPH SHOULD HELP TEMPS KEEP FROM DROPPING TOO FAR WED EVENING...THOUGH HAVE STILL GONE A BIT BLO COLDEST FWC NUMBERS.

S/WV MOVES ACROSS FCST AREA THURSDAY...WITH MODELS IN AGREEMENT IN DROPPING SECOND WAVE IN BY LATE IN THE DAY. TSECTS INDICATE LOW LEVELS MOISTEN DURG THE AFTN HOURS AS LLVL COLD ADVECTION STARTS TO KICK IN...THOUGH MOISTURE FAIRLY SHALLOW AND LIFT FOCUSED MORE IN MID LEVELS. WRF/GFS DO ATTEMPT TO KICK OUT SOME VERY LIGHT QPF MAINLY NORTH OF THE FA HOWEVER...SO WILL MAINTAIN CHC OF FLURRIES DURG MAX LLVL CAA/SATURATION THURSDAY NIGHT.

FOR REMAINDER OF FCST...INCREASING SPREAD IN ENSEMBLE SOLUTIONS WITH PATTERN HEADING INTO NEXT WEEKEND. OVERALL TREND SUPPORTS MORE OF A TROUGHINESS ACROSS THE AREA...WITH PERHAPS BEST FOCUS FOR ORGANIZED PCPN ARRIVING SUN/SUN NGT. HPC FAVORING ECMWF/GEM HANDLING OF LATER PERIODS AND WILL NOT ARGUE AT THIS POINT. THUS WILL HAVE CHC LGT SNOW SUN/SUN NGT...THEN CHC SNOW SHOWERS/FLURRIES MONDAY/MON NGT. TEMPS REMAIN RELATIVELY COLD THRU PERIOD...ESPECIALLY IN WAKE OF COLD FRONT THURSDAY NIGHT/FRIDAY...AND WITH PASSAGE OF NEXT SFC HIGH PRES RIDGE FRI NGT/EARLY SAT.

RATZER

&&

.AVIATION...

A SURFACE HIGH OVER EASTERN NEBRASKA WILL DOMINATE THE WEATHER OVER THE MIDWEST AND WESTERN GREAT LAKES. THERE IS A BAND OF LAKE EFFECT SNOW THAT IS JUST EAST OF THE GARY AIRPORT. THIS BAND IS A RESULT OF THE WARM WATER OF LAKE MICHIGAN AND A LOCALIZED LOW LEVEL CONVERGENCE ZONE. AS OF NOW ONLY THE GARY AIRPORT MAY SEE SNOW. THE WIND WILL BE AROUND 320 TO 310 DEGREES AT 10 TO 12 KNOTS. THERE IS A VERY SMALL INVERSION AROUND 1660 FT. THE WIND IS 320 TO 334 DEGREES UP TO 941 MB. THIS FROM THE ACARS SOUNDING AT ORD. BY WEDNESDAY MORNING THE WIND IS FORECAST TO BECOME MORE WEST TO SOUTHWEST BY WEDNESDAY MORNING.

&&

.LOT WATCHES/WARNINGS/ADVISORIES... .IL...NONE. .IN...NONE. .LM...SMALL CRAFT ADVISORY THROUGH TUESDAY NIGHT.

&&

$$

.DISCUSSION FOR MORNING UPDATE...

RADAR INDICATES LES BAND SNAKING BACK TO THE WEST LAST HOUR OR SO...AND WILL LIKELY IMPINGE FARTHER WEST INTO LAKE CO IND DURG NXT HOUR OR SO. RECENT ACARS DESCENT SOUNDINGS FROM KORD INDICATE SOME DIRECTIONAL SHEAR PRESENT IN LOWER 8000 FT...WITH NNE WINDS BETWEEN 3000-7500 FT. THIS HELPING BAND SHIFT TO THE WEST...THOUGH SHORT TERM MODEL GUIDANCE FROM WRF INDICATES A LITTLE MORE OF A SHIFT BACK TO NWLY FLOW IN THIS LAYER LATER THIS AFTERNOON. BASED ON CURRENT RADAR TRENDS HOWEVER...WILL HAVE TO UP POPS...AND MENTION POTENTIAL FOR 1-3 INCHES MAINLY NE LAKE/NORTHERN PORTER THIS AFTN. SOME CLOUD COVER LIKELY TO AFFECT IL SHORE AREAS AS WELL.

ZFP/GRIDS SHORTLY.

RATZER

PREVIOUS DISCUSSION FOR MORNING GRIDS/ZONES...

FOR THE VERY NEAR TERM...THE LIGHT SNOW IS WINDING DOWN OVER THE CWA AS LOW AND MID LEVEL FLOW IS BEGINNING TO TURN MORE ANTICYCLONIC OVER THE REGION. DURING THE PRE-DAWN HOURS THIS MORNING...SOME LINGERING SNOW SHOWERS WILL REMAIN OVER NERN IL...ESPECIALLY OVER ERN LAKE AND COOK COUNTIES IN IL...WHILE SKIES BEGIN TO CLEAR OVER NRN PORTIONS OF THE STATE. CLEARING SKIES WILL SPREAD SEWD DURG THE DAY TODAY. THE EXCEPTION WILL BE OVER NWRN INDIANA WHERE LAKE EFFECT SNOWS WL CONTINUE INTO THE LATE MORNING HOURS. MUCH OF THE LAKE EFFECT SNOW HAS ALREADY BEEN SHUNTED EWD OVER FAR ERN PORTER COUNTY...BUT A LITTLE LIGHT SNOW IS POSSIBLE OVER ERN LAKE COUNTY...INDIANA THIS MORNING. AS THE SFC RIDGE BUILDS EWD TODAY...THE CWA WL SEE CLEARING SKIES...BUT FLOW WL TURN MORE NWLY...SETTING UP A STG COLD ADVECTIVE PATTERN AND TEMPS WILL REACH THE COOLEST LEVELS THAT REGION HAS SEEN IN QUITE SOME TIME. HAVE GENERALLY UNDERCUT TEMP GUIDANCE FOR TODAY`S HIGHS AND TOMORROW MORNING`S LOWS GIVEN THE MOSTLY CLEAR SKIES AND A BIT OF SNOW COVER. TEMPS OVER MUCH OF THE CWA SHOULD DROP BELOW 0F...WITH THE EXCEPTION OF URBANIZED AREAS AND LOCATIONS INVOF LAKE MICHIGAN WHICH SHOULD REMAIN ABV ZERO...BUT WILL STILL BE IN THE SINGLE DIGITS.

BY WEDNESDAY...THE CENTER OF THE SFC HIGH WILL HAVE PASSED EAST OF THE LOCAL AREA AND LOW LEVEL FLOW WL TURN SLY...ALLOWING TEMPS TO MODERATE. THE NEXT CHANCE FOR ANY PCPN WILL NOT BE UNTIL THURSDAY AFTERNOON AND EVENING. THE MODEL GUIDANCE IS IN DECENT AGREEMENT ON HANDLING THE NEXT SYSTEM TO IMPACT THE UPPER MID WEST. THIS SYSTEM HAS ALREADY MOVED ONSHORE INTO THE NRN CANADIAN ROCKIES AND THE MAIN SFC LOW IS EXPECTED TO TRACK ACROSS THE CANADIAN PRAIRIES. THIS LOW SHOULD DRAG A WEAK COLD FRONT ACROSS THE REGION THURSDAY EVENING...BRINGING SOME MORE LIGHT SNOW. BUT GIVEN THE PACIFIC ORIGIN OF THIS SYSTEM...NOT EXPECTING TEMPS TO DROP BLW 0F...BUT SOME SINGLE DIGIT LOW ARE LIKELY FOR SATURDAY MORNING. LOW LEVEL FLOW IS LOOKING CONDUCIVE FOR ADDITIONAL LAKE EFFECT SNOW FOR NWRN INDIANA ON FRIDAY AND SATURDAY...AS FLOW TURNS NWLY BEHIND THE EXITING COLD FRONT AND AND SFC RIDGING BUILDS FROM THE SRN PLAINS THROUGH THE UPPER MISSISSIPPI VALLEY.

KREIN

&&

.AVIATION...

A SURFACE HIGH OVER EASTERN NEBRASKA WILL DOMINATE THE WEATHER OVER THE MIDWEST AND WESTERN GREAT LAKES. THERE IS A BAND OF LAKE EFFECT SNOW THAT IS JUST EAST OF THE GARY AIRPORT. THIS BAND IS A RESULT OF THE WARM WATER OF LAKE MICHIGAN AND A LOCALIZED LOW LEVEL CONVERGENCE ZONE. AS OF NOW ONLY THE GARY AIRPORT MAY SEE SNOW. THE WIND WILL BE AROUND 320 TO 310 DEGREES AT 10 TO 12 KNOTS. THERE IS A VERY SMALL INVERSION AROUND 1660 FT. THE WIND IS 320 TO 334 DEGREES UP TO 941 MB. THIS FROM THE ACARS SOUNDING AT ORD. BY WEDNESDAY MORNING THE WIND IS FORECAST TO BECOME MORE WEST TO SOUTHWEST BY WEDNESDAY MORNING.

&&

.LOT WATCHES/WARNINGS/ADVISORIES... .IL...NONE. .IN...NONE. .LM...SMALL CRAFT ADVISORY THROUGH TUESDAY NIGHT.

&&

$$

.MORNING UPDATE:... ONLY MINOR TWEAKS NEEDED TO TEMP TRENDS FOR TODAY...REMAINDER OF FCST STILL LOOKS GOOD. --21

.SHORT TERM (TDA AND TONIGHT)...

MID JAN WEATHER FINALLY...THO WE`RE NOT COMPLAINING. EXPECT WIDESPREAD FLURRIES/SCT TO NUMEROUS SNOW SHOWERS...TEMPS AROUND FREEZING TDA. READINGS DROPPING INTO THE TEENS TNGT.

UPR LEVEL TROF TO APPROACH OUR FA TDA AND MOVE THRU EARLY TNGT...WITH A SHRTWV RIDGE QUICKLY IN ARREARS. LO CLOUDS/FLURRIES OBSERVED ATTM UPSTREAM FROM MO INTO IL AND IN. CURRENT ACARS SOUNDING INDICATING MOISTURE UP TO ABOUT 850 MBS AT A TEMP OF ABOUT -11C. FCST SOUNDINGS SHOW MOISTURE DEEPENING A BIT UP TO ABOUT 800 MBS TDA AT TEMPS AROUND -15C AS LO LEVEL WINDS VEER TO NNW...RESULTING IN A FETCH OFF LAKE MI PRIMARILY AFFECTING OUR E/NE SECTIONS OF THE FCST AREA. MODELS SHOW SIMILAR LO LVL MSTR PROGS TDA WITH THE GFS INDICATING .01 TO .05 WATER EAST. THINKING SNOW SHOWERS WILL BE NUMEROUS PRIMARILY IN THE BLUEGRASS TDA...WITH SCT SNOW SHOWERS WEST OF THERE AND JUST FLURRIES SCNTRL KY. DAYLIGHT/RELATIVELY WARM GROUND TEMPS SHUD INHIBIT ACCUMS...WILL USE LITTLE OR NO ACCUM TERMINOLOGY EAST WITH LIKELY POPS.

WE SHUD START OFF AROUND THE 30 DEGREE MARK AT SUNRISE MOST PLACES AND WITH COLD ADVECTION...HOLD NEARLY STEADY WITH 850 MB THERMAL TROF ACRS OUR FA THIS AFTN.

CLOUDS WILL DECREASE TNGT WITH TROF PASSAGE...THO SNOW SHOWERS/FLURRIES MAY CONT EAST EARLY THIS EVE...WILL END HOWEVER AT OOZ TO BE CONSISTENT WITH PREVIOUS FCST. TEMPS TO FALL INTO THE TEENS MOST AREAS.

DK

LONG-TERM (WEDNESDAY THROUGH MONDAY)...

FOR THE MAJORITY OF THIS WEEK...TEMPS WILL GENERALLY RUN AT OR JUST BELOW NORMALS FOR THIS TIME OF YEAR. THIS IS RELATIVELY MUCH COLDER THAN THE TEMPS WE HAVE EXPERIENCED THUS FAR THIS YEAR...AS WE ARE RUNNING 12-13 DEGREES ABOVE NORMAL FOR JANUARY!

WEDNESDAY-THURSDAY...

SFC HIGH PRESSURE AND MAINLY ZONAL FLOW ALOFT WILL DOMINATE WED AND THRS ACROSS THE REGION. WITH LIGHT WINDS AND DRY CONDITIONS...WED AND WED NIGHT WILL BE COLD WITH HIGHS IN THE 30S TO NEAR 40 DOWN SOUTH...AND LOWS IN THE LOW 20S. WILL BE A BIT WARMER ON THRS AS HIGH PRESSURE SLIDES EAST AND SOUTHERLY FLOW COMMENCES.

FRIDAY-MONDAY...

AT THE BEGINNING OF THIS PERIOD...A CLOSED LOW WILL BE LOCATED OVER THE SWRN CONUS. BEFORE THIS MOVES EASTWARD...STRONG NORTHWEST FLOW ACROSS THE NRN U.S. WILL BRING A REINFORCING SHOT OF COLD ARCTIC AIR INTO THE REGION LATE FRIDAY AND INTO SATURDAY. HOWEVER...IF THE CLOSED LOW BECOMES MORE OF AN OPEN WAVE AND MOVES MORE QUICKLY EASTWARD...THIS ARCTIC AIR WOULD BE MORE TO OUR N/NE. CURRENT GRID TEMPS REFLECT A MINOR REINFORCEMENT WHICH LOOKS GOOD SO NO ADJUSTMENTS NEEDED.

ON FRIDAY...THE UPPER JET IS FAIRLY ZONAL AND STRONG...AROUND 160-180KTS. BECAUSE OF THE FAST ZONAL FLOW ALOFT...THINK THE CLOSED LOW OVER SWRN CONUS WILL QUICKLY EJECT OUT INTO THE PLAINS. MOST RECENT MRF MODEL RUNS OPEN UP THIS LOW OVER THE CENTRAL PLAINS BY SUNDAY MORNING. BUT THE TREND FROM THE PAST FOUR (THREE/TWO) RUNS OF THE GFS (GFS ENSEMBLES/ECMWF) HAVE REALLY SPED THIS UP. FOR INSTANCE...THE 06Z GFS RUN FROM YESTERDAY HAD THE UPPER LOW WELL OFF THE SE CALI COAST FRIDAY MORNING. THE 00Z RUN HAS THE OPENING LOW OVER ARIZONA. THE RESULT IS THAT THE SOUTHERN STREAM IS SHOWING QPF GETTING CONTINUALLY CLOSER TO OUR SRN CWA. IF THE MODELS CONTINUE THIS PROGRESSIVE TREND...THEN MAY HAVE TO INSERT PRECIP INTO THE FORECAST SOONER. IN FACT...THE GFS ENSEMBLES SHOW A BIT OF QPF ACROSS OUR SRN CWA ON FRIDAY WITH THE FIRST PUSH OF MOISTURE TOWARD THE REGION. WILL HAVE TO WATCH LATER RUNS TO SEE IF THIS HOLDS. FOR NOW WILL JUST BEEF UP CLOUDS DOWN SOUTH.

SECOND (MAIN) WAVE OF MOISTURE FROM THE SOUTHERN STREAM LOOKS TO OCCUR DURING THE SUNDAY-MONDAY TIMEFRAME WHEN THE UPPER LOW EJECTS OUT INTO THE MIDWEST. AGAIN...IF MODEL TREND CONTINUES...THIS WOULD OCCUR SOONER. RIGHT NOW WE HAVE POPS IN THE GRIDS SUNDAY NIGHT...BUT MAY NEED A SOONER ONSET IF MORE PROGRESSIVE MODEL TREND CONTINUES.

FOR NOW...MADE NO POP CHANGES...BUT ADJUSTED TEMPS DOWN ON WEDNESDAY...CLOSER TO THE OFTEN-TIMES UNJUSTLY IGNORED FWC GUIDANCE.

AL

&&

.LMK WATCHES/WARNINGS/ADVISORIES... KY...NONE. IN...NONE. &&

$$

.SHORT TERM (TDA AND TONIGHT)...

MID JAN WEATHER FINALLY...THO WE`RE NOT COMPLAINING. EXPECT WIDESPREAD FLURRIES/SCT TO NUMEROUS SNOW SHOWERS...TEMPS AROUND FREEZING TDA. READINGS DROPPING INTO THE TEENS TNGT.

UPR LEVEL TROF TO APPROACH OUR FA TDA AND MOVE THRU EARLY TNGT...WITH A SHRTWV RIDGE QUICKLY IN ARREARS. LO CLOUDS/FLURRIES OBSERVED ATTM UPSTREAM FROM MO INTO IL AND IN. CURRENT ACARS SOUNDING INDICATING MOISTURE UP TO ABOUT 850 MBS AT A TEMP OF ABOUT -11C. FCST SOUNDINGS SHOW MOISTURE DEEPENING A BIT UP TO ABOUT 800 MBS TDA AT TEMPS AROUND -15C AS LO LEVEL WINDS VEER TO NNW...RESULTING IN A FETCH OFF LAKE MI PRIMARILY AFFECTING OUR E/NE SECTIONS OF THE FCST AREA. MODELS SHOW SIMILAR LO LVL MSTR PROGS TDA WITH THE GFS INDICATING .01 TO .05 WATER EAST. THINKING SNOW SHOWERS WILL BE NUMEROUS PRIMARILY IN THE BLUEGRASS TDA...WITH SCT SNOW SHOWERS WEST OF THERE AND JUST FLURRIES SCNTRL KY. DAYLIGHT/RELATIVELY WARM GROUND TEMPS SHUD INHIBIT ACCUMS...WILL USE LITTLE OR NO ACCUM TERMINOLOGY EAST WITH LIKELY POPS.

WE SHUD START OFF AROUND THE 30 DEGREE MARK AT SUNRISE MOST PLACES AND WITH COLD ADVECTION...HOLD NEARLY STEADY WITH 850 MB THERMAL TROF ACRS OUR FA THIS AFTN.

CLOUDS WILL DECREASE TNGT WITH TROF PASSAGE...THO SNOW SHOWERS/FLURRIES MAY CONT EAST EARLY THIS EVE...WILL END HOWEVER AT OOZ TO BE CONSISTENT WITH PREVIOUS FCST. TEMPS TO FALL INTO THE TEENS MOST AREAS.

DK

LONG-TERM (WEDNESDAY THROUGH MONDAY)...

FOR THE MAJORITY OF THIS WEEK...TEMPS WILL GENERALLY RUN AT OR JUST BELOW NORMALS FOR THIS TIME OF YEAR. THIS IS RELATIVELY MUCH COLDER THAN THE TEMPS WE HAVE EXPERIENCED THUS FAR THIS YEAR...AS WE ARE RUNNING 12-13 DEGREES ABOVE NORMAL FOR JANUARY!

WEDNESDAY-THURSDAY...

SFC HIGH PRESSURE AND MAINLY ZONAL FLOW ALOFT WILL DOMINATE WED AND THRS ACROSS THE REGION. WITH LIGHT WINDS AND DRY CONDITIONS...WED AND WED NIGHT WILL BE COLD WITH HIGHS IN THE 30S TO NEAR 40 DOWN SOUTH...AND LOWS IN THE LOW 20S. WILL BE A BIT WARMER ON THRS AS HIGH PRESSURE SLIDES EAST AND SOUTHERLY FLOW COMMENCES.

FRIDAY-MONDAY...

AT THE BEGINNING OF THIS PERIOD...A CLOSED LOW WILL BE LOCATED OVER THE SWRN CONUS. BEFORE THIS MOVES EASTWARD...STRONG NORTHWEST FLOW ACROSS THE NRN U.S. WILL BRING A REINFORCING SHOT OF COLD ARCTIC AIR INTO THE REGION LATE FRIDAY AND INTO SATURDAY. HOWEVER...IF THE CLOSED LOW BECOMES MORE OF AN OPEN WAVE AND MOVES MORE QUICKLY EASTWARD...THIS ARCTIC AIR WOULD BE MORE TO OUR N/NE. CURRENT GRID TEMPS REFLECT A MINOR REINFORCEMENT WHICH LOOKS GOOD SO NO ADJUSTMENTS NEEDED.

ON FRIDAY...THE UPPER JET IS FAIRLY ZONAL AND STRONG...AROUND 160-180KTS. BECAUSE OF THE FAST ZONAL FLOW ALOFT...THINK THE CLOSED LOW OVER SWRN CONUS WILL QUICKLY EJECT OUT INTO THE PLAINS. MOST RECENT MRF MODEL RUNS OPEN UP THIS LOW OVER THE CENTRAL PLAINS BY SUNDAY MORNING. BUT THE TREND FROM THE PAST FOUR (THREE/TWO) RUNS OF THE GFS (GFS ENSEMBLES/ECMWF) HAVE REALLY SPED THIS UP. FOR INSTANCE...THE 06Z GFS RUN FROM YESTERDAY HAD THE UPPER LOW WELL OFF THE SE CALI COAST FRIDAY MORNING. THE 00Z RUN HAS THE OPENING LOW OVER ARIZONA. THE RESULT IS THAT THE SOUTHERN STREAM IS SHOWING QPF GETTING CONTINUALLY CLOSER TO OUR SRN CWA. IF THE MODELS CONTINUE THIS PROGRESSIVE TREND...THEN MAY HAVE TO INSERT PRECIP INTO THE FORECAST SOONER. IN FACT...THE GFS ENSEMBLES SHOW A BIT OF QPF ACROSS OUR SRN CWA ON FRIDAY WITH THE FIRST PUSH OF MOISTURE TOWARD THE REGION. WILL HAVE TO WATCH LATER RUNS TO SEE IF THIS HOLDS. FOR NOW WILL JUST BEEF UP CLOUDS DOWN SOUTH.

SECOND (MAIN) WAVE OF MOISTURE FROM THE SOUTHERN STREAM LOOKS TO OCCUR DURING THE SUNDAY-MONDAY TIMEFRAME WHEN THE UPPER LOW EJECTS OUT INTO THE MIDWEST. AGAIN...IF MODEL TREND CONTINUES...THIS WOULD OCCUR SOONER. RIGHT NOW WE HAVE POPS IN THE GRIDS SUNDAY NIGHT...BUT MAY NEED A SOONER ONSET IF MORE PROGRESSIVE MODEL TREND CONTINUES.

FOR NOW...MADE NO POP CHANGES...BUT ADJUSTED TEMPS DOWN ON WEDNESDAY...CLOSER TO THE OFTEN-TIMES UNJUSTLY IGNORED FWC GUIDANCE.

AL

&&

.LMK WATCHES/WARNINGS/ADVISORIES... KY...NONE. IN...NONE. &&

$$

.SHORT TERM (TONIGHT THROUGH THURSDAY NIGHT)... WATER VAPOR LOOP SHOWS AN UPPER LOW LIFTING INTO THE CENTRAL CONUS...AS A STRONGER UPPER LOW DROPS THROUGH SOUTHERN CALIFORNIA. A NORTHERN STREAM WAVE WAS PROGRESSING EAST ACROSS THE NORTHERN ROCKIES. ACARS 400-250MB WIND OBSERVATIONS REVEAL A 125-175KT WESTERLY UPPER LEVEL JET FROM THE SOUTHWEST CONUS EAST ACROSS THE GULF STATES. 20Z SURFACE ANALYSIS PLACED A 1041MB ANTICYCLONE ACROSS UPSTATE NEW YORK...WITH A 1040MB ANTICYCLONE ACROSS EASTERN VIRGINIA. A SOUTH CENTRAL CANADIAN WARM FRONT BECOMES STATIONARY AND THEN SINKS SOUTHEAST ACROSS THE NEW ENGLAND WATERS AS A COLD FRONT BETWEEN THE TWO AREAS OF HIGH PRESSURE.

A CLEAR SKY WILL TRANSITION TO INCREASING UPPER LEVEL MOISTURE AS WEAK UPPER LEVEL RIDGING PASSES EAST. WITH HIGH PRESSURE IN CONTROL AT THE SURFACE...DECOUPLING AND DRY ATMOSPHERE (0.11" PRECIPITABLE WATER FROM 00Z KIAD RAOB) HAVE LED TO LIGHT WINDS WHICH WILL ALLOW TEMPERATURES TO FALL QUICKLY BEFORE CLOUDS INVADE.

THE SKY WILL FILL WITH MID LEVEL CLOUDS THURSDAY MORNING IN ADVANCE OF THE NEXT NORTHERN STREAM SYSTEM. FORECAST HIGH TEMPERATURES ARE BELOW MOS GIVEN RECENT PERFORMANCE AND EXPECTED CLOUDINESS.

CHALLENGE CONTINUES TO BE POSSIBILITY OF LIGHT QPF FROM COASTAL SYSTEM LATE TOMORROW AND INTO TOMORROW NIGHT. PREVIOUS FORECAST UPDATE ACCOUNTED FOR A SHARPER WESTERN EDGE AND LIGHTER QPF AS A CONSENSUS FROM 18Z NAM/GFS...ALONG WITH THE 15Z SHORT RANGE ENSEMBLES. STRONG ZONAL UPPER LEVEL JET ACROSS THE GULF STATES HAS TRAPPED DEEP LAYER MOISTURE NEAR THE GULF COAST. AS THE JET STRENGTHENS AND BEGINS TO LIFT NORTH IN RESPONSE TO THE APPROACH OF THE NORTHERN STREAM WAVE...LOW LEVEL ISENTROPIC UPGLIDE WILL BEGIN TO TRANSPORT MOISTURE NORTHWARD NEAR THE NOSE OF THE UPPER LEVEL JET (EAST OF APPALACHIANS). WITH PHASING OCCURRING ACROSS THE NEW ENGLAND WATERS LATE THIS WEEK...APPEARS THAT THE BRUNT OF THE WARM ADVECTION (AND THUS PRECIPITATION) WILL BE ALONG AND EAST OF THE DELMARVA. WITH WEAK VERTICAL MOTION EXPECTED...DECIDED TO KEEP A RAIN/SNOW MIX AS THERMAL PROFILES ARE NEAR 0C...EXCEPT A LITTLE WARMER IN THE BOUNDARY LAYER. WOULD NOT BE SURPRISED TO SEE A BIT OF SLEET AT ONSET AS EVAPORATIONAL COOLING AFFECTS TAKE PLACE.

&&

.AVIATION... UPPER LEVEL MOISTURE BEGINS TO FILTER IN OVERNIGHT AND BUILDS INTO THE MID LEVELS TOMORROW. WARM ADVECTION ALLOWS SOUTHERLY FLOW TO DOMINATE TOMORROW AFTER A LIGHT AN VARIABLE START. CANT RULE OUT LIGHT RAIN/SNOW FROM THE COASTAL SYSTEM BY EARLY EVENING NEAR KDCA/KBWI WITH MVFR CEILINGS.

&&

.MARINE... LIGHT WINDS AS THE SURFACE HIGH BUILDS OFF THE EAST COAST LATE TONIGHT. WITH A SURFACE PRESSURE COL IN THE AREA...EXPECT LIGHT WINDS THURSDAY.

12Z ETA/18Z MAV MOS AT THOMAS POINT INDICATE WINDS 10 KT OR LESS THROUGH THE SHORT TERM. 18Z NAM/GFS PROXIMITY BUFKIT FORECAST SOUNDINGS SHOW LITTLE ADDITIONAL MOMENTUM TRANSFER.

&&

.TIDES... WATER LEVELS ARE CURRENTLY A HALF FOOT TO A FOOT BELOW ASTRONOMIC PREDICTIONS. THE LUNAR CYCLE IS WANING (2% FULL) TO A NEW MOON. BLOWOUT CONDITIONS HAVE LET UP DURING THE AFTERNOON.

THE CHESAPEAKE BAY OPERATIONAL FORECAST SYSTEM AND THE NOAA EXTRATROPICAL STORM SURGE MODEL BOTH SUGGEST TIDAL DEPARTURES RECOVER TO OR SLIGHTLY ABOVE ASTRONOMIC PERDITIONS THURSDAY.

&&

.LWX WATCHES/WARNINGS/ADVISORIES... DC...NONE. MD...NONE. VA...NONE. WV...NONE. MARINE...NONE.

&&

$$

SHORT TERM/AVIATION/MARINE/TIDES...ROGOWSKI

.SHORT TERM (THROUGH FRI)...ARCTIC AIR IS FINALLY ERODING FROM THE REGION...MOST SLOWLY FOR RED RIVER VALLEY WHERE IT IS 5-10F DEGREES COLDER THAN EITHER SIDE ATTM. CLOUDS PASSING OVER APPEAR TO BE NOT AFFECTING THE WARMING TREND. MODEL SOUNDINGS SHOW THE SURFACE BASED INVERSION TO BE NO MORE THAN 2 KFT DEEP MOST SPOTS WHILE UP TO 10C WARMER ON TOP. 1847Z CYWG AMDAR SOUNDING CONFIRMS THAT AND IS EVEN MORE EXTREME. AM TEMPTED TO FORECAST STEADY/SLOWLY RISING TEMPERATURES TONIGHT BUT THE LIMITED CLOUD COVER ARRIVING FROM THE NORTHWEST WILL BE DISSIPATED AND MOVING ON BY 06Z. EXPECT THE TOO MUCH VERTICAL DIRECTIONAL SHEAR TO ENSURE DECOUPLED LOW LEVEL JET TO MAKE WARM AIR MIXING DOWNWARD TO BE UNLIKELY TONIGHT. SO LEANED ON THE WARMER NAM/NGM MOS GUIDANCE THOUGH SURFACE WARMING WILL OCCUR RELATIVELY QUICK ON WED MORNING.

NEXT SIGNIFICANT 5H SHORTWAVE HAS ENTERED NORTHERN B.C. AND MODELS HAVE SLOWED ITS ARRIVAL TO THU. BOTH NAM/GFS SHOW A NARROW RIBBON OF STRONG ISENTROPIC LIFT AT 280-285K PASSING OVER IN A SECONDARY SHORTWAVE IMMEDIATELY AFTER THE MAIN TROUGH...WHICH SHOWS BETTER POTENTIAL FOR SATURATING THE LOW LEVELS FOR MEASURABLE SNOW. MIXING RATIOS BY THEN DECREASE TO LESS THAN 1 G/KG SO WILL NOT SUGGEST MORE THAN AN INCH THAT DAY. ARCTIC AIR RETURNS THU NIGHT/FRI BUT WILL NOT BE AS COLD AS THE AIR MASS LEAVING ATTM. .LONG TERM (SAT-TUE)... THE OVERALL PATTERN WILL BE DOMINATED BY NW FLOW AND RIDGING INTO THE PACIFIC WEST COAST. THIS WILL MEAN SLIGHT CHANCES FOR LIGHT SNOW...WITH THE STRONGEST CLIPPER TYPE SYSTEM MOVING THROUGH SUNDAY AND SUNDAY NIGHT. THE BEST FORCING WILL BE ACROSS NORTHERN AREAS...BUT BY SUNDAY NIGHT EVEN THE SOUTH WILL SEE A LOW CHANCE FOR LIGHT SNOW. OTHERWISE...EXPECT A DRY PERIOD WITH TEMPS NEAR NORMAL.

&&

.AVIATION... EXPECT VFR CONDITIONS TO PREVAIL AT ALL TAF SITES THROUGH 18Z WED.

&&

.FGF WATCHES/WARNINGS/ADVISORIES... ND...NONE. MN...NONE. &&

$$

GV

.UPDATE...MINIMAL CHANGES TO TODAYS GRIDS/ZONES. 12Z NAM SLIGHTLY UNDERESTIMATED SOME OF THE UPSTREAM WARM AIR ALOFT ACCORDING TO AMDAR SOUNDINGS AT CYQR/CYWG AT 800-850 MB OR SO. BUT POOR MOMENTIVE TRANSFER THIS AFTERNOON/EVENING EXPECTED WITH WINDS THAT HIGH DUE TO DIRECTIONAL VERTICAL SHEAR SO DO NOT EXPECT ANY CONSEQUENCE. BOOSTED CLOUDS A BIT IN ZONES THOUGH GRIDS DON/T LOOK TOO BAD. WILL LIKELY ADJUST THOSE UPWARD TOO WITH LOTS OF MID/HIGH CLOUDS TO STREAM ACROSS NORTH HALF OF CWA.

&&

.FGF WATCHES/WARNINGS/ADVISORIES... ND...NONE. MN...NONE. &&

$$

GV

.SYNOPSIS...A FRONT WILL BRUSHING WESTERN WASHINGTON TONIGHT AND THURSDAY WILL BRING PRECIPITATION TO MAINLY THE COAST AND NORTHWEST INTERIOR. THE WEATHER PATTERN WILL REMAIN UNSETTLED THROUGH SATURDAY FOR A CONTINUED CHANCE OF PRECIPITATION. HIGH PRESSURE ALOFT AND LOW LEVEL OFFSHORE FLOW WILL RESULT IN DRY WEATHER EARLY NEXT WEEK.

&&

.SHORT TERM... LIGHT PRECIP AHEAD OF A WMFNT OFF THE WA COAST HAD OVERSPREAD MUCH OF THE CWA THIS EVENING. EXPECT THE PRECIP TO PERSIST THE REMAINDER OF THE NIGHT AS THE WMFNT CONTINUES TO MOVE SLOWLY E.

MEANWHILE...WARM AIR ADVECTION WAS OCCURRING AHEAD OF THE FRONT... WITH ACARS DATA INDICATING THE FREEZING LEVEL BETWEEN 1500 AND 2000 FT OVER THE INTERIOR. ON THE COAST...THE FREEZING LEVEL WAS NEAR 2300 FT EARLIER THIS EVENING. SURFACE DEW POINTS WERE ALSO UP... MOSTLY IN THE LOWER TO MID 30S...AND NOT MUCH CHANGE IN THE DEW POINTS IS EXPECTED OVERNIGHT. THEREFORE THE THREAT OF SNOW HAS ENDED FOR THE LOWLANDS...ALTHOUGH THE RAIN WILL LIKELY BE MIXED WITH SNOW AT TIMES AT OR ABOVE THE 500 FOOT LEVEL. OTHERWISE THE AREAS MOST LIKELY TO SEE SNOW WILL BE THE HOOD CANAL ZONE AND THE EAST PUGET SOUND LOWLANDS...HOWEVER ANY ACCUMULATION WILL BE LESS THAN AN INCH. THE FORECAST WAS UPDATED ACCORDINGLY.

THE WEAKENING WMFNT WILL MOVE ACROSS THE NW PORTION OF THE CWA DURING THE DAY THU AND THEN DISSIPATE AS IT MOVES INTO BRITISH COLUMBIA. THE PRECIP THREAT SHOULD THEN BECOME CONFINED TO MOSTLY THE COAST AND FAR NW INTERIOR BY THE END OF THE DAY. THE LATEST NAM/WRF AND GFS INDICATED THAT MUCH OF THE INTERIOR WILL BE DRY THU NIGHT.

.LONG TERM...FROM THE PREV DISCUSSION...12Z GFS PRETTY UNEQUIVOCAL ABOUT OFFSHORE FLOW DEVELOPING SUNDAY AND CONTINUING INTO NEXT WEEK. UPPER RIDGE ALSO BUILDS. DETAILS FLUCTUATE FROM RUN TO RUN BUT FOR NOW AM SATISFIED TREND IS TOWARD DRIER WEATHER. HAVE REMOVED PCPN FROM SUNDAY ON. TEMPS SHOULD BE CLOSE TO CLIMATOLOGICAL AVERAGES...45 TO 50 FOR HIGHS AND 35 TO 40 FOR LOWS. BURKE

&&

.AVIATION...WITH WEAK WARM ADVECTION AND LIGHT OFFSHORE GRADIENTS...CEILINGS WILL BE HIGHLY VARIABLE WITH BASICALLY A MIX OF LOW AND MID CLOUDS. RAIN WILL CONTINUE TO SPREAD OVER THE AREA...NOT VERY HEAVY OR STEADY HOWEVER. LOWEST CEILINGS SHOULD BE TOWARD THE COAST AND NORTH PART WHERE RAIN WILL BE MORE PREVALENT.

KSEA...2000-5000 FT CEILINGS THROUGH THE NIGHT WITH LIGHT RAIN. NOT EXPECTING ANY SIGNIFICANT VISIBILITY RESTRICTIONS...GENERALLY GREATER THAN 5 MILES. CERNIGLIA

&&

.SEW WATCHES/WARNINGS/ADVISORIES...SMALL CRAFT ADVISORY COASTAL WATERS AND WEST ENTRANCE TO THE STRAIT OF JUAN DE FUCA.

$$

WEATHER.GOV/SEATTLE

.SHORT TERM /REST OF TODAY/... 12Z UPPER AIR ANALYSIS REVEALED TWO FEATURES THAT WILL [LAY MAJOR ROLES IN P-TYPE THIS AFTERNOON. FIRST, DRIER AIR NOTED UPSTREAM OF CENTRAL NC IN THE 700-500MB LAYER. THIS LAYER COINCIDES IN FAVORED DENDRITE REGION. WITH MOISTURE DECREASING...EXPECT SNOW TO DIMINISH NEXT FEW HOURS. ALSO NOTED WAS STRONG FETCH OF WARMER AIR AROUND 850MB UPSTREAM. THIS WARM AIR SURGE ALSO NOTED IN AIRCRAFT SOUNDINGS FROM CLT AND AREA VAD WIND PROFILES FROM ACROSS AREA. THUS EXPECT PATCHES OF SNOW OVER THE NW PIEDMONT TO TRANSITION TO FREEZING RAIN NEXT COUPLE HOURS WITH MAINLY LIGHT PRECIP EXPECTED THROUGH THE AFTERNOON. DO NOT EXPECT THE TRIAD REGION TO WARM TO AROUND FREEZING UNTIL LATE IN THE DAY. THE PERSISTENT FREEZING PRECIP WILL LIKELY RESULT IN ICE ACCUMULATION OF A TENTH OF AN INCH.

IN THE NE PIEDMONT...WIDESPREAD FREEZING RAIN WILL TRANSITION TO RAIN AS SURFACE TEMPS RISE TO AROUND FREEZING WITH MUCH WARMER AIR ALOFT. WILL MAINTAIN CATEGORICAL POPS FOR NOW. EXPECT PRECIP TO DIMINISH SW-NE LATE TODAY AND EARLY TONIGHT.

FINALLY...ADJUSTED MAX TEMPS DOWN A DEGREE OR TWO...MAINLY IN THE NORTHERN PIEDMONT.

&&

.PREV DISCUSSION... /ISSUED 617 AM EST THU JAN 18 2007/

SHORT TERM /REST OF TODAY THROUGH SATURDAY NIGHT/... THE WINTER WEATHER ADVISORY HAS BEEN EXPANDED TO INCLUDE THE NORTHERN COASTAL PLAIN UNTIL NOON TODAY.

PREV DISCUSSION... /ISSUED 412 AM EST THU JAN 18 2007/

CORRECTION TO WSW ENDING TIME NW PIEDMONT. RFG

PREV DISCUSSION... /ISSUED 339 AM EST THU JAN 18 2007/

UPDATE... RADAR ECHOES ARE RAPIDLY SPREADING ACROSS CENTRAL NC. MOST PCPN REMAINS ALOFT...BUT SOME IN THE FORM OF SNOW HAS BEEN REPORTED IN THE SOUTHERN TIER COUNTIES. ADVISORIES HAVE REVERTED TO THEIR EARLIER START TIMES OF 4 AM ACROSS THE SOUTH AND 6 AM ACROSS THE NORTH TO MAKE PEOPLE AWARE THAT PCPN IS BEGINNING TO REACH THE GROUND AS EARLIER PREDICTED. -RFG

PREV DISCUSSION... /ISSUED 220 AM EST THU JAN 18 2007/

SHORT TERM /TODAY THROUGH SATURDAY NIGHT/... TODAY...STRONG JET ALOFT WITH 160+ KTS OUT OF THE RED RIVER VALLEY TOWARD NC IS HELPING TO DRAW WARMER MOIST AIR ALOFT FROM THE GULF STATES TOWARD THE CAROLINAS. RADAR SHOWS DEVELOPING PCPN AREAS FROM ALABAMA EASTWARD WITH JUST A SLIGHT NORTHWARD PROGRESSION. MOIST SOUTHERLY FLOW ALOFT IS ENCOUNTERING AND BEGINNING TO OVERRUN MUCH DRIER AIR OVER CENTRAL NC AND MOST PCPN IS LIKELY TO EVAP/SUBLIMATE FOR SEVERAL HOURS BEFORE THE COLUMN SATURATES OVER THIS AREA.

CURRENT ALIGNMENT OF WINTER WEATHER ADVISORIES WILL BE KEPT IN PLACE ACROSS CENTRAL NC...BUT ONSET DELAYED A COUPLE HOURS...AND POSSIBLY ENDING EARLIER. AREAS OF PCPN IN THE FORM OF SLEET OR FRZG RAIN SHOULD START IN THE SRN TIER TOWARD DAYBREAK...WITH MEASURABLE PCPN AS FAR NORTH AS HIGHWAY 64 BY 10 AM AND AS FAR NORTH AS THE VA BORDER AROUND NOON.

MODEL THICKNESS VALUES ARE SHOWING A MORE RAPID WARMUP DURING THE DAY MEANING A QUICKER TRANSITION FROM SLEET TO FRZG RAIN TO RAIN. DRYNESS IN THE DENDRITE GROWTH ZONE ALOFT SUGGESTS NEGLIGIBLE CHANCES OF SNOW. PROGNOSES OF SURFACE WET BULB TEMPERATURES SHOWS THE THREAT OF FREEZING RAIN RETREATING WEST OF U.S. ROUTE 1 BY 10 AM AND LIMITED TO THE TRIAD AROUND NOON...ABOVE FREEZING THROUGHOUT THE CWA AFTER 1 PM.

GIVEN THE TIGHT GRADIENT WESTERLY FLOW ALOFT...THERE IS LITTLE OPPORTUNITY FOR WAVE AMPLIFICATION...EFFECTIVELY CUTTING OFF THE NORTHWARD SURGE OF WARM MOIST AIR. THIS SHOULD MEAN RAPIDLY DECREASING QPF NORTHWARD OVER THE NRN TIER OF CENTRAL NC. EXPECT QPF OF .25-.50 IN THE SOUTHEAST THIRD TAPERING TO ONLY A FEW HUNDREDTHS OF AN INCH IN THE NORTHERN TIER OF COUNTIES. MAX TEMPERATURES NEAR 34 IN THE TRIAD TO 43 IN SAMPSON CO.

TNGT..THE THREAT OF RAIN CONTINUES IN THE EASTERN HALF UNTIL AROUND MIDNIGHT WITH SKIES REMAINING CLOUDY THROUGHOUT OVERNIGHT. THE RAIN COOLED PIEDMONT AIRMASS SHOULD LINGER INTO FRI. LOWS OF 30 NW TO 37 SE MEANS SOME ICY PATCHES IN THE NW THIRD ARE POSSIBLE EARLY FRI. -RFG

FRIDAY AND FRIDAY NIGHT...THE SFC CYCLONE WILL CONTINUE TO DEPART THE REGION AS IT HEADS FURTHER NORTHEAST. THIS WILL LEAVE THE CWA IN DRY NORTHWEST FLOW BOTH AT THE SFC AND ALOFT. FORECAST SOUNDINGS INDICATE THAT MIXING SHOULD OCCUR TO NEAR 850 MB WHERE WINDS OF 40 TO 45 KTS WILL BE PRESENT. MEANWHILE...THE SFC PRESSURE GRADIENT TIGHTENS OVER CENTRAL NORTH CAROLINA AS THE ATLANTIC LOW DEEPENS AND HIGH PRESSURE MOVES INTO THE CENTRAL U.S. THESE FACTORS WILL RESULT IN BREEZY CONDITIONS WITH WINDS POSSIBLY GUSTING TO 25 TO 30 MPH DURING THE AFTERNOON. TEMPERATURES WILL ALSO CONTINUE TO BE ON THE COOL SIDE AS LOW LEVEL THICKNESSES INDICATE HIGHS IN THE MID TO UPPER 40S...WHICH ARE LOWER THAN THE CONSENSUS MOS. LOWS FRIDAY NIGHT WILL DIP INTO THE MID 20S TO NEAR 30.

SATURDAY AND SATURDAY NIGHT...COOL DRY NORTHWEST FLOW WILL PERSIST ACROSS THE FORECAST AREA. A REINFORCING SHOT OF COOLER AIR FILTERS INTO THE AREA ON SATURDAY AFTERNOON...EVIDENT BY 850MB TEMPS DROPPING TO AROUND -8C. HIGHS ARE ONCE AGAIN EXPECTED TO BE BELOW MOS GUIDANCE...FROM AROUND 40 IN THE NE PIEDMONT TO MID 40S IN THE COASTAL PLAIN. LOW LEVEL THICKNESS TECHNIQUE SUGGESTS IT MAY BE EVEN COOLER THAN THIS...SO WILL CONTINUE TO MONITOR.

SFC HIGH PRESSURE SETTLES OVER CENTRAL NC BY SUNDAY MORNING. LIGHT WINDS AND LOW DEWPOINTS POINT TO A VERY CHILLY NIGHT...BUT INCREASING MID TO HIGH LEVEL CLOUDS WILL LIKELY HOLD TEMPS UP SOMEWHAT. TEMPS STILL EXPECTED TO DROP INTO THE 20S. -JFB

LONG TERM /SUNDAY THROUGH WEDNESDAY/... NOT A LOT OF CONFIDENCE IN THE TIMING OF THE EVENT LATE THIS WEEKEND AS MODEL EVOLUTION WAS FAST LAST NIGHT...AND HAS SPED UP EVEN MORE TONIGHT. LOW PRESSURE RACES ACROSS THE SOUTHERN STATES AND THE TRANSITORY COLD HIGH WILL BE REINFORCED AS PRECIP OVERSPREADS THE AREA SUNDAY AFTERNOON/EVENING. WARM AIR ASSOCIATED WITH THE OVERRUNNING WILL BE STRONG WITH A 50KT LLJ...THUS MIXED PRECIP IS A FAIR BET AS EVAPORATIVE COOLING COULD EASILY LOCK TEMPS IN THE CLIMATOLOGICALLY FAVORED AREA IN THE 30S ALL DAY. THERMAL STRUCTURE AND TIMING OF THE ONSET IS STILL QUITE UNCERTAIN...WILL ONLY MENTION R/S FOR NOW UNTIL THE TIMING MATTER IS RESOLVED. OTHERWISE...WILL BE ENDING THE PRECIP A LITTLE EARLIER AS ON MONDAY...OTHERWISE NO CHANGES TO THE LATER EXTENDED. -MM

AVIATION /06Z-06Z/... VFR CONDS EARLY IN THE TAF PERIOD WILL GIVE WAY TO MVFR/IFR CIGS AND VIS FOR THE REMAINDER OF THE TAF PERIOD AS PRECIP DEVELOPS AND ADVECTS INTO THE CWA FROM THE SOUTH BETWEEN 10-13Z THIS MORNING. PRECIP IS EXPECTED TO BEGIN AS SNOW AT GSO...TRANSITIONING TO SN/PL AND EVENTUALLY FZRA BY 18Z. FZRA AND EVENTUALLY RAIN ARE EXPECTED FOR THE REMAINDER OF THE TAF PERIOD AT GSO. AT RDU/FAY...PRECIP IS MORE APT TO BEGIN AS FZRA BEFORE TRANSITIONING TO RAIN BY 15-18Z...ALTHOUGH A BRIEF PERIOD OF SN/PL CANNOT BE RULED OUT AT ONSET. AT RWI...PRECIP WILL LIKELY FALL AS RAIN WITH THE EXCEPTION OF A BRIEF PERIOD OF FZRA AT ONSET. PRECIP ASSOC/W THE WEAK COASTAL LOW WILL END FROM SOUTHWEST TO NORTHEAST NEAR THE END OF THE TAF PERIOD. -VINCENT/MM

&&

.RAH WATCHES/WARNINGS/ADVISORIES... WINTER WEATHER ADVISORY UNTIL NOON EST TODAY FOR NCZ008>011- 025>028-040-041-043-073>076-083-084.

WINTER WEATHER ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR NCZ007-021>024-038-039.

&&

$$

SHORT TERM...WSS

.SYNOPSIS...RAIN WILL DECREASE BY THIS AFTERNOON AS THE WEAK WARM FRONT OVER WESTERN WASHINGTON MOVES NORTH INTO BRITISH COLUMBIA. RAIN WILL SPREAD IN FROM THE WEST TONIGHT AND FRIDAY AS THE ASSOCIATED WEAK COLD FRONT MOVES INLAND. COOLER NORTHWEST FLOW WILL BRING MORE SHOWERY WEATHER FRIDAY NIGHT AND SATURDAY. ANOTHER WARM FRONT WILL CROSS THE AREA SATURDAY NIGHT AND SUNDAY. AN UPPER LEVEL RIDGE ALONG THE COAST MAY BRING DRIER WEATHER EARLY NEXT WEEK.

&&

.SHORT TERM...LIGHT RAIN CONTINUES OVER MOST OF THE AREA THIS MORNING WITH SOME LIGHT SNOW BEING REPORTED ABOVE ABOUT 500 FEET. ACARS SOUNDINGS AROUND MIDNIGHT POINT TO A FREEZING LEVEL AROUND 1500 FEET. 06Z MODELS AND LATEST IR SATELLITE IMAGERY SUPPORT CONTINUED WARM ADVECTION THROUGH THIS MORNING...THEN FINALLY LIFTING MOSTLY UP INTO B.C. THIS AFTERNOON. WITH LOW FREEZING LEVELS HAVE KEPT THE MENTION OF SNOW THIS MORNING AND WORDED IT ABOVE 500 FEET. HAVE BACKED OFF TO A CHANCE OF RAIN FOR MUCH OF SOUTH PART OF THE AREA THIS AFTERNOON AS THE WARM FRONT LIFTS NORTH. THE TRAILING WEAK COLD FRONT COMES THROUGH LATE TONIGHT AND FRIDAY AS EXPECTED...POPS CATEGORICAL.

NONDESCRIPT POST FRONTAL WNW FLOW FRIDAY NIGHT-SATURDAY BUT GFS SHOWS A NICE COLD POOL MOVING OVER THE AREA. MOS POPS REMAIN UP SO HAVE KEPT HIGH CHANCE POPS FOR SHOWERS MOST OF THE LOWLANDS...LIKELY COAST AND OROGRAPHIC AREAS. SNOW LEVELS ONLY MAKE IT TO 1000-1500 FEET IN ONSHORE FLOW SO NO SNOW WORDING FOR THE LOWLANDS.

BIGGEST CHANGE IS THE MODELS GOING BACK TO A WARM ADVECTION LIGHT RAIN PATTERN SATURDAY NIGHT-SUNDAY. THE `OPEN DOOR` RIDGE AXIS ALONG 130W AT THAT TIME LOOKS ALMOST EXACTLY LIKE THE ONE OUT THERE RIGHT NOW. 500 MB HEIGHTS OVER W WA JUST ABOUT THE SAME AT 564 DM. BOTH ECMWF AND CANADIAN SUPPORT THE GFS WARM ADVECTION SOLUTION. KAM

.LONG TERM...GFS IS STILL BEING A TEASE SHOWING MAYBE SOME DRY WEATHER FOR PARTS OF MONDAY-THURSDAY OR MAYBE PART OF THE FORECAST AREA. THE PATTERN REMAINS ABOUT THE SAME MONDAY-TUESDAY WITH THE UPPER LEVEL RIDGE AXIS ALONG THE COAST AND WEAK SYSTEMS BEING DIRECTED UP OVER THE RIDGE AND ACROSS VANCOUVER ISLAND. GFS ACTUALLY SHOWS SOME LIGHT QPF OVER THE NORTHERN ZONES OR ALONG THE BORDER BOTH DAYS. WILL DEFER CHANGES TO THE DAY SHIFT...BUT WITH THE MODELS STILL BEING SHAKY...THE DRY FORECAST MAY BE AS WELL. KAM

&&

.AVIATION...WARM FRONT PUSHING TO THE COAST WITH CIGS RISING THERE AS AREA OF SIGNIFICANT LIFT IS INLAND AND MOVING EAST. SAT IMAGERY INDICATES ANOTHER SURGE OF LIFT MAY BE HEADED OUR WAY. PRECIP HAS BEEN HEAVY ENOUGH IN THIS COOL AIRMASS TO DRAG SNOW LEVELS VERY LOW...TO THE SURFACE ACROSS HIGHER TERRAIN. SO KSEA/KPWT HAVE A THREAT OF SOME LIGHT SNOW MUCH LIKE KPAE WHERE IT IS ALREADY SNOWING. NOT EXPECTING ANY ACCUMULATION OF CONCERN AND PRECIP SHOULD BE BACK TO JUST RAIN LATER THIS MORNING. CIGS ARE ABOUT AS BAD AS THEY WILL GET AND SHOULD IMPROVE SOME OVER INLAND AREAS TODAY.

KSEA...CIGS DROPPED INTO IFR...SOMEWHAT LOWER THAN EARLIER EXPECTED...GENERALLY DUE TO LOWERING SNOW LEVELS. EXPECT IFR TO LOW MVFR CIGS THROUGH MID MORNING WITH IMPROVEMENT TO 2000-5000 FT CEILINGS THEREAFTER. UNTIL ABOUT 14-16Z COULD GET SOME LIGHT SNOW WITH THE RAIN...BUT NOT EXPECTING PAVEMENT ACCUMULATIONS. WIND REMAINING S-SE 5-10 KTS TODAY. CERNIGLIA

&&

.SEW WATCHES/WARNINGS/ADVISORIES... SMALL CRAFT ADVISORY ALL WATERS EXCEPT CENTRAL STRAIT.

$$

WEATHER.GOV/SEATTLE

.UPDATE... FRESHENED UP WX/POPS/SNOW OVER FAR SE TIED TO SHORTWAVE TROUGH NOW MOVING INTO NORTHERN LK MI. NORTHERN LK MI ON FAR NORTH FRINGE OF DEEPER MOSITURE AND LIFT WITH THE SHORTWAVE. INCREASED POPS SLIGHTLY NEAR LK MICHIGAN SHORE EAST OF KESC...BUT BLYR WINDS HAVE TOO MUCH WESTERLY COMPONENT WITH 230-240 DIRECTIONS OBSERVED TO PROVIDE MUCH LAKE ENHANCEMENT TO SOUTHERN SCHOOLCRAFT. OTHERWISE...A FEW FLURRIES ARE AFFECTING OTHER PORTIONS OF CWA BTWN THE NORTHERN LK MICHIGAN SHORTWAVE AND ANOTHER SHORTWAVE/SFC TROUGH/H85 FRONT OVR NORTHERN MINNESOTA.

KDLH RADAR AND SFC OBS INDICATE TROUGH IS NEARING NE MN WITH LIGHT SNOW SPREADING INTO FAR REACHES OF WEST LK SUPERIOR. TAMDAR SOUNDINGS FM KSAW AND CYQT NOT VERY COLD AND DEEP WITH INVERSION THIS MORNING IN MOIST LAYER...AS LOW AS -10C AT CYQT WITH INVERSION AROUND H9. EVEN SO...LATEST VISIBLE SATELLITE LOOPS SHOW DEVELOPMENT OF LK EFFECT BAND OVR WESTERN LK SUPERIOR ORIENTED WSW TO ENE WITH STARTING POINT NEAR SILVER BAY MINNESOTA AND ENDING POINT JUST S OF ISLE ROYALE. EXPECT THIS BAND TO SIGNAL ARRIVAL OF TROUGH THIS EVENING WHILE DROPPING ACROSS KEWEENAW PENINSULA. SINCE IT IS ALREADY LOOKING STRONG ON SATELLITE...IT MAY PROVIDE A QUICK FEW INCHES OF SNOW THIS EVENING OVER THE KEWEENAW PENINSULA AND ADJACENT PORTION OF ONTONAGON COUNTY. LIGHT SNOW FM MN WILL SPREAD EAST... REACHING WEST HALF OF CWA BY THIS EVENING. NW WINDS BEHIND THE TROUGH AND H9-H85 TEMPS FALLING TO NEAR -20C BY 12Z FRI WILL ALLOW FOR INCREASE IN LK EFFECT IN NW FLOW AREAS AFTER MIDNIGHT. TWEAKED WORDING IN WSW TO TRY AND GET HANDLE ON THESE TRENDS. NO CHANGES WERE MADE TO GOING HEADLINES.

&&

.DISCUSSION (ISSUED AT 630 AM EST)... MAIN FCST CONCERN IS POTENTIAL FOR HVY LES NEAR LAKE SUPERIOR TONIGHT INTO FRI NIGHT.

WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW SEVERAL SHORTWAVES OVER THE CENTRAL AND WRN CONUS WITHIN TROF AMPLIFYING DOWNSTREAM OF RIDGE OVER W COAST. FIRST SHORTWAVE IS LIFTING ENE THRU CENTRAL WI AND DESPITE LIMITED MOISTURE TO WORK WITH...700-500 MB FGEN AND DPVA ASSOC WITH THIS FEATURE HAS RESULTED IN LIGHT SNOW/FLURRIES OVER SRN/CENTRAL WI. ANOTHER VORT MAX IS DIGGING INTO WRN NE INTO BASE OF AMPLIFYING MID-LVL TROF AND WILL BRING A COLD FRONT ACROSS UPR MI LATE TODAY AND TONIGHT. SEVERAL OTHER SHORTWAVES UPSTREAM OVER CANADA ARE POISED TO DROP OVER THE WRN GREAT LAKES LATE TONIGHT INTO FRI BRINGING REINFORCING SHOTS OF ARCTIC AIR AND INCREASED POTENTIAL FOR HEAVY LES.

TODAY...GIVEN THAT THERE ARE ALREADY REPORTS OF LIGHT SNOW/FLURRIES UPSTREAM OVER WI WITH SHORTWAVE LIFTING THROUGH THE AREA WILL KEEP IN A LOW CHC POPS FOR LIGHT SNOW OVER SCNTRL AND ERN COUNTIES TODAY. GENERALLY BETTER FORCING FROM THIS FEATURE WILL STAY SOUTH AND EAST OF FCST AREA. AS SECOND SHORTWAVE CONTINUES TO DIG THROUGH THE CENTRAL PLAINS INTO THE LOWER MIDWEST...AN ASSOCIATED COLD FRONT WILL MOVE THROUGH WRN UPR MI LATE THIS AFTERNOON AND EVENING. WINDS SHIFTING MORE WRLY BY LATE AFTERNOON ALONG WITH 850 MB TEMPS FALLING TO AROUND -12C BY 00Z AND Q-VECT CONV AHEAD OF SHORTWAVE SHOULD BRING UP TO 2 INCHES OF LES TO PORTIONS OF THE KEWEENAW PENINSULA.

TONIGHT INTO FRI NIGHT...CONDITIONS STILL LOOK GOOD FOR A MDT TO HVY LAKE ENHANCED EVENT TRANSITIONING TO PURE LES AS MODELS INDICATE 850MB TEMPS FALLING TO -20 TO -22C FRI. SHORTWAVE MOVING THROUGH IN THE EVENING WILL BRING DEEPER MOISTURE AND Q-VECT CONV FOR ENHANCEMENT TO LES AS 850 MB TEMPS BEGIN TO PLUMMET BEHIND THE SHORTWAVE LATE FRI NIGHT. WITH DEEPER MOISTURE AND ENHANCEMENT POTENTIAL LASTING LONGER OVER ERN COUNTIES HAVE DECIDED TO GO WITH AN LES WARNING FOR ALGER-LUCE AND NRN SCHOOLCRAFT COUNTIES FOR TOTAL SNOW ACCUMS OF MORE THAN A FOOT WITH AN LES ADVISORY FOR SRN SCHOOLCRAFT FOR LATE TONIGHT INTO SAT MORNING. OVER THE WESTERN COUNTIES...MODELS NOW INDICATE SHORTER WINDOW OF DEEPER MOISTURE/ENHANCEMENT (LATE TONIGHT/EARLY FRI) WITH A QUICKER TRANSITION TO PURE LES AS INVERSION HGTS LOWER TO AROUND 5 KFT IN THE AFTERNOON. THUS...HAVE DECIDED TO GO WITH A HIGH END LES ADVISORY LATE TODAY/THIS EVENING INTO FRI NIGHT FOR TOTAL ACCUMS OF 5 TO 11 INCHES. NW AND ERN MQT COUNTY ALONG WITH NRN IRON COUNTY COULD ALSO SEE LOCAL ACCUMS REACHING ADVISORY WITH FAIRLY STRONG NW FLOW. HIGH PRES RIDGE PASSING ACROSS UPPER MI WILL BRING AN END TO LINGERING LES FROM W TO E LATE FRI NIGHT INTO SAT MORNING.

TEMPS WILL GET COLDER BEGINNING FRI AS THERE WILL BE VERY LTL DIURNAL REBOUND FROM EARLY MORNING READINGS WITH A STRONG PUSH OF (-20C TO -22C 850 MB TEMPS) ARCTIC AIR. WITH HIGH PRES RIDGE NEARING LATE FRI NIGHT...TEMPS SHOULD PLUMMET TOWARD -10F OVER THE INTERIOR W HALF AS LAKE EFFECT CLOUDS BREAK.

&&

.MQT WATCHES/WARNINGS/ADVISORIES... HEAVY FREEZING SPRAY WARNING WRN LAKE SUPERIOR. LAKE EFFECT SNOW WARNING LATE THIS AFTERNOON THROUGH FRI NIGHT...MIZ001>003. LAKE EFFECT SNOW WARNING TONIGHT THROUGH FRI EVENING...MIZ009. LAKE EFFECT SNOW WARNING TONIGHT THROUGH FRI NIGHT...MI004. LAKE EFFECT SNOW WARNING LATE TONIGHT INTO SAT MORNING...MIZ006-007-085. LAKE EFFECT SNOW ADVISORY TONIGHT THROUGH FRI NIGHT...MIZ084. LAKE EFFECT SNOW ADVISORY LATE THIS EVENING THROUGH FRI NIGHT...MIZ005. LAKE EFFECT SNOW ADVISORY LATE TONIGHT THROUGH SAT MORNING...MIZ014.

&&

$$

UPDATE...JLA PREV DISCUSSION...VOSS

.SHORT TERM /REST OF TODAY/... RECENTLY UPDATED FORECAST TO ACCOUNT FOR DIMINISHING FREEZING RAIN THREAT IN THE NE PIEDMONT AND TO DOWNPLAY ICE ACCRUAL AMOUNTS IN THE NW PIEDMONT. APPEARS THAT BACK EDGE OF STEADY PRECIP OVER THE WESTERN AND SOUTHERN PIEDMONT LIFTING E-NE. STILL EXPECT WIDESPREAD DRIZZLE OVER THE PIEDMONT AND SANDHILLS /FREEZING DRIZZLE IN THE NW PIEDMONT/ THROUGH THE AFTERNOON AND POSSIBLY INTO THE EARLY EVENING HOURS. TEMPERATURES ON TRACK WITH JUST SLIGHT ADJUSTMENT REQUIRED.

&&

.PREV DISCUSSION... /ISSUED 1033 AM EST THU JAN 18 2007/

SHORT TERM /REST OF TODAY/... 12Z UPPER AIR ANALYSIS REVEALED TWO FEATURES THAT WILL [LAY MAJOR ROLES IN P-TYPE THIS AFTERNOON. FIRST, DRIER AIR NOTED UPSTREAM OF CENTRAL NC IN THE 700-500MB LAYER. THIS LAYER COINCIDES IN FAVORED DENDRITE REGION. WITH MOISTURE DECREASING...EXPECT SNOW TO DIMINISH NEXT FEW HOURS. ALSO NOTED WAS STRONG FETCH OF WARMER AIR AROUND 850MB UPSTREAM. THIS WARM AIR SURGE ALSO NOTED IN AIRCRAFT SOUNDINGS FROM CLT AND AREA VAD WIND PROFILES FROM ACROSS AREA. THUS EXPECT PATCHES OF SNOW OVER THE NW PIEDMONT TO TRANSITION TO FREEZING RAIN NEXT COUPLE HOURS WITH MAINLY LIGHT PRECIP EXPECTED THROUGH THE AFTERNOON. DO NOT EXPECT THE TRIAD REGION TO WARM TO AROUND FREEZING UNTIL LATE IN THE DAY. THE PERSISTENT FREEZING PRECIP WILL LIKELY RESULT IN ICE ACCUMULATION OF A TENTH OF AN INCH.

IN THE NE PIEDMONT...WIDESPREAD FREEZING RAIN WILL TRANSITION TO RAIN AS SURFACE TEMPS RISE TO AROUND FREEZING WITH MUCH WARMER AIR ALOFT. WILL MAINTAIN CATEGORICAL POPS FOR NOW. EXPECT PRECIP TO DIMINISH SW-NE LATE TODAY AND EARLY TONIGHT.

FINALLY...ADJUSTED MAX TEMPS DOWN A DEGREE OR TWO...MAINLY IN THE NORTHERN PIEDMONT.

PREV DISCUSSION... /ISSUED 617 AM EST THU JAN 18 2007/

SHORT TERM /REST OF TODAY THROUGH SATURDAY NIGHT/... THE WINTER WEATHER ADVISORY HAS BEEN EXPANDED TO INCLUDE THE NORTHERN COASTAL PLAIN UNTIL NOON TODAY.

PREV DISCUSSION... /ISSUED 412 AM EST THU JAN 18 2007/

CORRECTION TO WSW ENDING TIME NW PIEDMONT. RFG

PREV DISCUSSION... /ISSUED 339 AM EST THU JAN 18 2007/

UPDATE... RADAR ECHOES ARE RAPIDLY SPREADING ACROSS CENTRAL NC. MOST PCPN REMAINS ALOFT...BUT SOME IN THE FORM OF SNOW HAS BEEN REPORTED IN THE SOUTHERN TIER COUNTIES. ADVISORIES HAVE REVERTED TO THEIR EARLIER START TIMES OF 4 AM ACROSS THE SOUTH AND 6 AM ACROSS THE NORTH TO MAKE PEOPLE AWARE THAT PCPN IS BEGINNING TO REACH THE GROUND AS EARLIER PREDICTED. -RFG

PREV DISCUSSION... /ISSUED 220 AM EST THU JAN 18 2007/

SHORT TERM /TODAY THROUGH SATURDAY NIGHT/... TODAY...STRONG JET ALOFT WITH 160+ KTS OUT OF THE RED RIVER VALLEY TOWARD NC IS HELPING TO DRAW WARMER MOIST AIR ALOFT FROM THE GULF STATES TOWARD THE CAROLINAS. RADAR SHOWS DEVELOPING PCPN AREAS FROM ALABAMA EASTWARD WITH JUST A SLIGHT NORTHWARD PROGRESSION. MOIST SOUTHERLY FLOW ALOFT IS ENCOUNTERING AND BEGINNING TO OVERRUN MUCH DRIER AIR OVER CENTRAL NC AND MOST PCPN IS LIKELY TO EVAP/SUBLIMATE FOR SEVERAL HOURS BEFORE THE COLUMN SATURATES OVER THIS AREA.

CURRENT ALIGNMENT OF WINTER WEATHER ADVISORIES WILL BE KEPT IN PLACE ACROSS CENTRAL NC...BUT ONSET DELAYED A COUPLE HOURS...AND POSSIBLY ENDING EARLIER. AREAS OF PCPN IN THE FORM OF SLEET OR FRZG RAIN SHOULD START IN THE SRN TIER TOWARD DAYBREAK...WITH MEASURABLE PCPN AS FAR NORTH AS HIGHWAY 64 BY 10 AM AND AS FAR NORTH AS THE VA BORDER AROUND NOON.

MODEL THICKNESS VALUES ARE SHOWING A MORE RAPID WARMUP DURING THE DAY MEANING A QUICKER TRANSITION FROM SLEET TO FRZG RAIN TO RAIN. DRYNESS IN THE DENDRITE GROWTH ZONE ALOFT SUGGESTS NEGLIGIBLE CHANCES OF SNOW. PROGNOSES OF SURFACE WET BULB TEMPERATURES SHOWS THE THREAT OF FREEZING RAIN RETREATING WEST OF U.S. ROUTE 1 BY 10 AM AND LIMITED TO THE TRIAD AROUND NOON...ABOVE FREEZING THROUGHOUT THE CWA AFTER 1 PM.

GIVEN THE TIGHT GRADIENT WESTERLY FLOW ALOFT...THERE IS LITTLE OPPORTUNITY FOR WAVE AMPLIFICATION...EFFECTIVELY CUTTING OFF THE NORTHWARD SURGE OF WARM MOIST AIR. THIS SHOULD MEAN RAPIDLY DECREASING QPF NORTHWARD OVER THE NRN TIER OF CENTRAL NC. EXPECT QPF OF .25-.50 IN THE SOUTHEAST THIRD TAPERING TO ONLY A FEW HUNDREDTHS OF AN INCH IN THE NORTHERN TIER OF COUNTIES. MAX TEMPERATURES NEAR 34 IN THE TRIAD TO 43 IN SAMPSON CO.

TNGT..THE THREAT OF RAIN CONTINUES IN THE EASTERN HALF UNTIL AROUND MIDNIGHT WITH SKIES REMAINING CLOUDY THROUGHOUT OVERNIGHT. THE RAIN COOLED PIEDMONT AIRMASS SHOULD LINGER INTO FRI. LOWS OF 30 NW TO 37 SE MEANS SOME ICY PATCHES IN THE NW THIRD ARE POSSIBLE EARLY FRI. -RFG

FRIDAY AND FRIDAY NIGHT...THE SFC CYCLONE WILL CONTINUE TO DEPART THE REGION AS IT HEADS FURTHER NORTHEAST. THIS WILL LEAVE THE CWA IN DRY NORTHWEST FLOW BOTH AT THE SFC AND ALOFT. FORECAST SOUNDINGS INDICATE THAT MIXING SHOULD OCCUR TO NEAR 850 MB WHERE WINDS OF 40 TO 45 KTS WILL BE PRESENT. MEANWHILE...THE SFC PRESSURE GRADIENT TIGHTENS OVER CENTRAL NORTH CAROLINA AS THE ATLANTIC LOW DEEPENS AND HIGH PRESSURE MOVES INTO THE CENTRAL U.S. THESE FACTORS WILL RESULT IN BREEZY CONDITIONS WITH WINDS POSSIBLY GUSTING TO 25 TO 30 MPH DURING THE AFTERNOON. TEMPERATURES WILL ALSO CONTINUE TO BE ON THE COOL SIDE AS LOW LEVEL THICKNESSES INDICATE HIGHS IN THE MID TO UPPER 40S...WHICH ARE LOWER THAN THE CONSENSUS MOS. LOWS FRIDAY NIGHT WILL DIP INTO THE MID 20S TO NEAR 30.

SATURDAY AND SATURDAY NIGHT...COOL DRY NORTHWEST FLOW WILL PERSIST ACROSS THE FORECAST AREA. A REINFORCING SHOT OF COOLER AIR FILTERS INTO THE AREA ON SATURDAY AFTERNOON...EVIDENT BY 850MB TEMPS DROPPING TO AROUND -8C. HIGHS ARE ONCE AGAIN EXPECTED TO BE BELOW MOS GUIDANCE...FROM AROUND 40 IN THE NE PIEDMONT TO MID 40S IN THE COASTAL PLAIN. LOW LEVEL THICKNESS TECHNIQUE SUGGESTS IT MAY BE EVEN COOLER THAN THIS...SO WILL CONTINUE TO MONITOR.

SFC HIGH PRESSURE SETTLES OVER CENTRAL NC BY SUNDAY MORNING. LIGHT WINDS AND LOW DEWPOINTS POINT TO A VERY CHILLY NIGHT...BUT INCREASING MID TO HIGH LEVEL CLOUDS WILL LIKELY HOLD TEMPS UP SOMEWHAT. TEMPS STILL EXPECTED TO DROP INTO THE 20S. -JFB

LONG TERM /SUNDAY THROUGH WEDNESDAY/... NOT A LOT OF CONFIDENCE IN THE TIMING OF THE EVENT LATE THIS WEEKEND AS MODEL EVOLUTION WAS FAST LAST NIGHT...AND HAS SPED UP EVEN MORE TONIGHT. LOW PRESSURE RACES ACROSS THE SOUTHERN STATES AND THE TRANSITORY COLD HIGH WILL BE REINFORCED AS PRECIP OVERSPREADS THE AREA SUNDAY AFTERNOON/EVENING. WARM AIR ASSOCIATED WITH THE OVERRUNNING WILL BE STRONG WITH A 50KT LLJ...THUS MIXED PRECIP IS A FAIR BET AS EVAPORATIVE COOLING COULD EASILY LOCK TEMPS IN THE CLIMATOLOGICALLY FAVORED AREA IN THE 30S ALL DAY. THERMAL STRUCTURE AND TIMING OF THE ONSET IS STILL QUITE UNCERTAIN...WILL ONLY MENTION R/S FOR NOW UNTIL THE TIMING MATTER IS RESOLVED. OTHERWISE...WILL BE ENDING THE PRECIP A LITTLE EARLIER AS ON MONDAY...OTHERWISE NO CHANGES TO THE LATER EXTENDED. -MM

AVIATION /06Z-06Z/... VFR CONDS EARLY IN THE TAF PERIOD WILL GIVE WAY TO MVFR/IFR CIGS AND VIS FOR THE REMAINDER OF THE TAF PERIOD AS PRECIP DEVELOPS AND ADVECTS INTO THE CWA FROM THE SOUTH BETWEEN 10-13Z THIS MORNING. PRECIP IS EXPECTED TO BEGIN AS SNOW AT GSO...TRANSITIONING TO SN/PL AND EVENTUALLY FZRA BY 18Z. FZRA AND EVENTUALLY RAIN ARE EXPECTED FOR THE REMAINDER OF THE TAF PERIOD AT GSO. AT RDU/FAY...PRECIP IS MORE APT TO BEGIN AS FZRA BEFORE TRANSITIONING TO RAIN BY 15-18Z...ALTHOUGH A BRIEF PERIOD OF SN/PL CANNOT BE RULED OUT AT ONSET. AT RWI...PRECIP WILL LIKELY FALL AS RAIN WITH THE EXCEPTION OF A BRIEF PERIOD OF FZRA AT ONSET. PRECIP ASSOC/W THE WEAK COASTAL LOW WILL END FROM SOUTHWEST TO NORTHEAST NEAR THE END OF THE TAF PERIOD. -VINCENT/MM

&&

.RAH WATCHES/WARNINGS/ADVISORIES... WINTER WEATHER ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR NCZ007-021>024-038-039.

&&

$$

SHORT TERM...WSS

.UPDATE...MADE SOME CHANGES TO THE FORECAST FOR TODAY BASED ON A FEW ITEMS. BY MID-MORNING...KARX RADAR HAD REALLY INCREASED THE ECHO COVERAGE EAST OF A LINE FROM KCCY-KONA-KMDZ. WITHIN THAT ECHO...A BROAD WEST-EAST BAND OF MORE ENHANCED ECHO /15-20 DBZ/ HAS BEEN ACTIVE FROM KCCY-KMSN ROUGHLY. THIS HAS BEEN ALL SNOW. LATEST NCEP RUC SHOWS A WEAK FRONTOGENETICAL FORCING REGION IN THE 850-700 MB LAYER IN THIS EXACT LOCATION. THIS LIFT AND FRONTAL CIRCULATION HAS PRODUCED 1-2 MI SNOW IN THAT AREA. THE RUC DOES SHIFT THIS AREA EAST WITH TIME THIS AFTERNOON. CALLS DOWN TO KPDC SAY AROUND ONE-HALF INCH HAS FALLEN SINCE MORNING...WITH BOAZ /NRN RICHLAND/ ONLY IN THE TENTH AREA.

SECOND AREA OF FORCING IS ALONG THE COLD FRONT ALONG A KFSD-KDLH LINE ROUGHLY AT 16Z. RADAR ECHOES ARE ALONG THAT BOUNDARY. THIS SHOULD ARRIVE AROUND MID-AFTERNOON IN THE WESTERN FORECAST AREA /KRST/. AT THE SAME TIME...A STRONG SHORTWAVE TROUGH AND POTENTIAL VORTICITY /PV/ ANOMALY OVER KSUX AT 16Z IS SHIFTING EAST AND WILL PROVIDE VERY GOOD FORCING ALOFT THIS AFTERNOON AND EARLY EVENING. THIS IS ALSO ENHANCING THE FRONTOGENETICAL CIRCULATION DISCUSSED ABOVE AT THIS TIME IN SWRN WI AND NERN IA.

SO...BOTTOM LINE IS UPDATED TO HAVE MORE WEATHER IN THE FORECAST TODAY AND ALL SN. KALO TAMDAR AT 16Z INDICATED PROBAIBLITIES ARE MORE TOWARD ICE INTORDUCTION RATHER THAN LIQUID /FZDZ/. WILL LIKELY NEED TO UPDATE THE GRIDS TONIGHT TO INCREASE THE SNOW CHANCES TOO. WOULD EXPECT AN INCH OR SO DOWN SOUTH IN THE BAND TODAY. THE FRONT LOOKS TO PROVIDE A QUICK ONE-HALF INCH AS IT MOVES THROUGH WITH THE PV ANOMALY. UPDATES ARE OUT FOR TODAY...WILL LOOK INTO EVENING UPDATES AND TRY TO SHIP PRIOR TO NOON. &&

.ARX WATCHES/WARNINGS/ADVISORIES... WI...NONE. MN...NONE. IA...NONE.

&&

$$

BAUMGARDT