PNSCHS/ ISSUED EARLIER WITH A LISTING OF LOW TEMPERATURES OBSERVED. BTW...RECORD LOWS WERE DEFINITELY NOT SET AT KCHS OR KSAV...BUT THERE COULD HAVE BEEN A TIE AT KCHL...ALTHOUGH THIS WON/T BE KNOWN FOR SURE UNTIL AFTER MIDNIGHT TONIGHT. OTHERWISE...AS CLOUD COVER INCREASES THROUGH THE DAY...EXPECT TEMPERATURES WILL BE HELD DOWN SOMEWHAT. BASED ON THE LATEST NAM MOS AND GFS LAMP GUIDANCE...WILL LOWER HIGHS WELL INLAND WHERE THE CLOUDS WILL COME IN QUICKER...RESULTING IN HIGHS CLOSE TO 40 DEGREES FOR NORTHERN AND WESTERN PORTIONS OF OUR FORECAST AREA WITH MID 40S ELSEWHERE. SOME UPPER 40S ARE POSSIBLE ACROSS SOUTHEAST GEORGIA...MAINLY AROUND DARIEN. ALSO ADJUSTED TEMPS UP A BIT THIS EVENING WHERE CLOUD COVER SHOULD PREVENT TEMPS FALLING AS QUICKLY AS ADVERTISED. && .SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY/... THE MID LEVEL SHORT WAVE IS FORECAST TO SPLIT INTO SEVERAL WAVES IN THE PROGRESSIVE UPPER TROUGH AXIS TONIGHT. THE STRONGER OF THE MID LEVEL VORTICITY MAXIMA IS EXPECTED TO SWING THROUGH S GEORGIA AND OFF OUR COAST LATE. MODELS SHOW A LOWERING AND THICKENING SHIELD OF MID LEVEL MOISTURE IN ADVANCE OF THIS FEATURE SPREADING OVER OUR FORECAST AREA DURING THE EVENING. THE QUICK PROGRESSION AND LACK OF LOWER MOISTURE SUPPORT...SUGGESTS THAT ANY MEASURABLE PRECIPITATION IS QUITE UNLIKELY. A FAST BOUT OF STRONG UPPER FORCING AND SOME NEAR-COASTAL FRONTOGENESIS HAVE IMPLICATIONS THAT LIGHT FLURRIES OR RAIN/SNOW SPRINKLES MAY CROP UP SOMEWHERE CLOSER TO THE COAST THIS EVENING INTO THE FIRST PART OF THE OVERNIGHT AROUND THE CHARLESTON TRI-COUNTY AREA. FORECAST SOUNDINGS HAVE SOME DECENT MOISTURE IN FAVORABLE SNOW GROWTH REGIONS ALOFT BUT LOWER LEVELS REMAIN BONE DRY AND TIMING IS A BIT UNCERTAIN. WE CERTAINLY CANNOT RULE OUT A FEW FLURRIES TONIGHT TO THE E OF I-95 IN SOUTH CAROLINA BUT CONFIDENCE WAS NOT HIGH ENOUGH TO WORK THEM INTO THE FORECAST AT THIS POINT. TEMPERATURES MAY HOLD A BIT WARMER THIS EVENING UNDER THE THICKER CLOUD DECKS... THEN DIP INTO THE LOWER TO MID 20S AFTER SOME LATE NIGHT CLEARING OCCURS. UPPER LEVEL ENERGY WILL CONTINUE TO MOVE OFF THE SOUTHEAST COAST INTO THE ATLANTIC ON THURSDAY...SPAWNING A WEAK AREA OF LOW PRESSURE NEAR THE BAHAMAS. THIS WILL ACT TO SWING WINDS TO THE NORTHEAST...ALLOWING FOR A SLOW MODERATION IN TEMPS INTO THE FIRST HALF OF THE WEEKEND. AN INCREASE IN MOISTURE WILL ALSO BE EVIDENT...ESPECIALLY ON THE COAST WHERE PERIODIC PATCHES OF LOW CLOUDS ARE EXPECTED. ALL THE SIGNIFICANT PRECIPITATION SHOULD STAY OFFSHORE...HOWEVER. AS THE MODIFIED ARCTIC HIGH PRESSURE AREA THAT HAS BEEN DOMINATING THE EAST COAST MOVES INTO THE ATLANTIC FRIDAY AND SATURDAY...LOW LEVEL TEMPERATURES AND HUMIDITIES WILL RECOVER TO NEAR NORMAL VALUES BY SATURDAY AFTERNOON. DAYTIME TEMPS WILL BE COOLEST NEAR THE COAST WHERE AN SLIGHT ONSHORE COMPONENT WILL KEEP TEMPS DOWN A BIT. && .LONG TERM /SATURDAY NIGHT THROUGH TUESDAY/... A STRONG COLD FRONT TRAILING FROM DEVELOPING LOW PRESSURE OVER THE UPPER MIDWEST WILL APPROACH QUICKLY FROM THE WEST SATURDAY NIGHT...CAUSING AN INCREASE IN CLOUDS AND SOUTHERLY WINDS. I THINK MOST OF THE PRECIP SHOULD HOLD OFF OVERNIGHT. ON SUNDAY...ALL MODELS ARE IN AGREEMENT THAT A STRONG COLD FRONT WILL MOVE THROUGH THE AREA. I HAVE AGAIN INCREASED POPS FROM THE PREVIOUS FORECAST TO THE NEIGHBORHOOD OF 50 PERCENT AS THE MODELS CONTINUE TO BE IN PRETTY GOOD AGREEMENT WITH TIMING. IT LOOKS LIKE AIR MASS AHEAD OF THE FRONT WILL BE TOO STABLE TO SUPPORT THUNDER. TEMPS ARE VERY DIFFICULT ON SUNDAY. IF THE FRONT HOLDS OFF UNTIL LATER IN THE DAY...THERE COULD BE SOME PRETTY GOOD WARMING INTO THE 60S. IF THE COLD FRONT COMES THROUGH EARLIER...DAYTIME TEMPS WILL EB QUITE A BIT COOLER. FOR NOW...I AIMED TOWARD THE MIDDLE OF THE ROAD APPROACH WITH 60S OVER THE EASTERN HALF OF THE AREA AND 50S FURTHER WEST. SUNDAY NIGHT SOME VERY STRONG COLD ADVECTION STARTS TO KICK IN BEHIND THE FRONT. LOW TEMPS MONDAY MORNING ARE AGAIN HIGHLY DEPENDENT ON THE EXACT TIMING OF THE FRONT...WITH ENSEMBLE GUIDANCE GIVING LOW TEMP VALUES AT CHS RANGING FROM 21 TO 45. NEEDLESS TO SAY...TRYING TO PIN DOWN AN EXACT TEMP THIS EARLY IN THE GAME IS NOT EASY...SO I HAVE FOLLOWED A COMPROMISE. ALL MODELS AGREE THAT VERY STRONG LOW LEVEL COLD ADVECTION WILL BE IN FULL FORCE MONDAY AND MONDAY NIGHT. 00Z GFS HAS 850 TEMPS AT CHS BY 06Z TUESDAY OF -17C! GFS BUFR SOUNDINGS INDICATE DAYTIME MAX TEMPS STRUGGLING TO GET OUT OF THE MID 30S ON MONDAY. THIS TYPE OF GUIDANCE USUALLY CARRIES A BIT OF A COLD BIAS...BUT IF SUCH STRONG COLD ADVECTION MATERIALIZES...I THINK IT UNLIKELY WE WOULD REACH 40 MANY PLACES. STILL...I AM NOT WILLING TO GO THAT COLD YET SO FAR OUT...BUT I DID LOWER THE TEMPS MONDAY AND MONDAY NIGHT. EVEN IF THE TEMPS MAKE IT TO 40...A BRISK NORTHWESTERLY WIND IN EXCESS OF 20 MPH MOST PLACES WILL MAKE IT FEEL QUITE A BIT COLDER. ITS NOT IMPOSSIBLE THAT WE WILL NEED WIND CHILL ADVISORIES FOR MONDAY NIGHT IF THE CURRENT TRENDS CONTINUE. MUCH BELOW NORMAL WEATHER SHOULD CONTINUE TUESDAY AND WEDNESDAY AS ARCTIC HIGH PRESSURE DOMINATES THE SOUTHEAST AGAIN. && .AVIATION /18Z WEDNESDAY THROUGH MONDAY/... VFR THROUGH 09/18Z. WINDS MAINLY FROM THE N OR NE AT SPEEDS BELOW 10 KT. MID AND HIGH CLOUDS INCREASING THROUGH AROUND 09Z AS AN UPPER DISTURBANCE PUSHES THROUGH FROM THE W. AT THIS TIME IT APPEARS IT WILL BE TOO DRY IN THE LOWER LEVELS TO GET ANY PRECIPITATION TO THE GROUND BUT COULD NOT RULE OUT AT LEAST SOME FLURRIES FROM ABOUT 00-06Z. EXTENDED AVIATION OUTLOOK...VFR THROUGH FRIDAY. SOME MVFR CIGS POSSIBLE SATURDAY AS LOW LEVEL MOISTURE RETURNS. SOME MVFR/IFR CIGS/VSBYS POSSIBLE SUNDAY WITH SHOWERS ACCOMPANYING THE COLD FRONT PASSAGE. VFR AGAIN ON MONDAY. GUSTY WINDS EXPECTED SUNDAY AND MONDAY. && .MARINE... SURGING OVER THE WATERS THIS MORNING IS EXPECTED TO DIMINISH TODAY WITH NO ADVISORY CONDITIONS EXPECTED. MODELS ARE TRENDING STRONGER WITH THE SURGE TONIGHT FOR ALL WATERS AS A SHORT UPPER DISTURBANCE MOVES OFF THE COAST LATE AND TIGHTENING LOW LEVEL PRES GRADIENTS EXPECTED AS SURFACE PRES FALLS OCCUR OFF THE FLORIDA COAST AND HIGH PRES STRENGTHENS OVER THE MID ATLC REGION. WE HAVE INCREASING WINDS AND SEAS FROM OUR PREVIOUS PACKAGE A BIT AFTER MIDNIGHT AND ISSUED A SMALL CRAFT ADVISORY FOR OUR 20-60 NM GEORGIA WATERS AS N WINDS INCREASE TO A SOLID 20 KT WITH HIGHER GUSTS AND SEAS BUILD TO 4 TO 6 FT. WILL NEED TO WATCH THE PINCHING CLOSE TO GRAYS REEF AS SCA CONDITIONS MAY BE POSSIBLE THERE LATE. OTHERWISE WINDS PICKING UP INTO THE 15 TO 20 KT RANGE WITH SEAS 3-4 FT. WINDS SEAS WILL BE UP OVER THE OFFSHORE GEORGIA WATERS THROUGH FRIDAY DUE TO A SOMEWHAT PINCHED GRADIENT BETWEEN HIGH PRESSURE ALONG THE MID ATLANTIC COAST AND A WEAK AREA OF LOW PRESSURE NEAR THE BAHAMAS. SCA WILL BE NEEDED THERE THROUGH THE END OF THE WEEK. WINDS SHOULD REMAIN BELOW CRITERIA FOR THE NEARSHORE WATERS...ALTHOUGH STILL A BIT GUSTY AT TIMES. AFTER A RELATIVELY QUIET DAY IN BETWEEN SYSTEMS ON SATURDAY...WINDS WILL SHIFT TO THE SOUTH SATURDAY NIGHT AND INCREASE SIGNIFICANTLY AHEAD OF THE APPROACHING COLD FRONT. SCA WILL LIKELY BE NEEDED AGAIN BY EARLY SUNDAY MORNING...THIS TIME OVER ALL THE COASTAL WATERS. SEAS WILL ALSO INCREASE ACCORDINGLY. THE COLD FRONT SHOULD MOVE THROUGH THE COASTAL WATERS DURING THE SECOND HALF OF SUNDAY...CAUSING THE WINDS TO SHIFT TO THE NORTHWEST. VERY STRONG COLD ADVECTION WILL THEN COMMENCE LATER SUNDAY NIGHT AND MONDAY. HIGHLIGHTS WILL BE NEEDED FOR ALL WATERS WITH GALES LIKELY OVER THE OUTER GEORGIA WATERS...AND POSSIBLY EVEN CLOSER TO THE COAST IN A WORST CASE. && .CLIMATE... RECORD LOWS FOR DECEMBER 8-9... DECEMBER 8 KCHS 20/1954 KSAV 20/1965 KCHL 30/1937 DECEMBER 9 KCHS 19/2006 KSAV 20/1968 KCHL 27/1917 && .CHS WATCHES/WARNINGS/ADVISORIES... GA...NONE. SC...NONE. MARINE...SMALL CRAFT ADVISORY FROM MIDNIGHT TONIGHT TO 10 PM EST FRIDAY FOR AMZ374. && $$