Heavy Snow in Georgia, February 12, 2010

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
246 PM EST FRI FEB 12 2010

.SYNOPSIS...
A MOIST LOW PRESSURE SYSTEM WILL MOVE OFF THE SOUTHEAST COAST
TONIGHT AND SATURDAY WHILE HIGH PRESSURE RETURNS TO THE CAROLINAS
OVER THE WEEKEND. A COLD FRONT THEN APPROACHES FROM THE WEST EARLY
ON MONDAY. ANOTHER AREA OF HIGH PRESSURE WILL BUILD BACK IN ACROSS
THE REGION BY THE MIDDLE OF NEXT WEEK.

&&

.NEAR TERM /THROUGH SATURDAY/...
SFC LOW PRESSURE WAS LOCATED ABOUT 200 MILES SOUTH SOUTHEAST OF
PANAMA CITY AS OF 18 UTC. THE LOW IS DEEPENING AND MOVING QUICKLY
OFF TO THE EAST...WHICH IS GENERALLY CONSISTENT WITH MOST OF THE
MODEL SOLUTIONS. THE 12 UTC NAM WAS TOO SUPPRESSED WITH IT/S PCPN
SHIELD...WHILE THE GFS LOOKED A LITTLE TOO WET. THE SREF IS AN NICE
COMPROMISE OF THE TWO AND I/VE STAYED FAIRLY CLOSE TO IT/S QPF AND
TIMING FORECAST...AS WELL AS THE OUTPUT OF IT/S PLUME DIAGRAMS. IT
HAS THE HEAVIEST PCPN WITH THE SYSTEM OVER THE SE PART OF THE
FA...WHICH IS CONSISTENT ALSO WITH THIS MORNING/S 4KM WRF.

THE REASON FOR ALL THIS EXPLANATION IS THAT WE ARE VERY CLOSE TO
WARNING CRITERIA OVER PARTS OF THE FA WHERE WE CURRENTLY HAVE AN
ADVISORY. I/M GOING TO STICK TO MY GUNS AND KEEP THE CURRENT
WARNINGS AND ADVISORIES WHERE THEY ARE...BUT WE/LL HAVE TO PAY CLOSE
ATTENTION TO ACCUMULATIONS AS THEY DEVELOP. CURRENTLY AN AREA OF
MODERATE SNOW HAS STARTED TO BECOME MORE WIDESPREAD OVER OVER NW GA
AND NRN AL...WITH A SECOND AREA OF MODERATE TO HEAVY SNOW DEVELOPING
OVER S CENTRAL AL AND GA. MY SUSPICION IS THAT THE SOUTHERN AREA OF
SNOW WILL BECOME THE DOMINATE ONE AS PCPN STARTS TO SHIFT TO THE
EAST....AFFECTING THE SRN UPSTATE...DOWN TOWARD THE COASTAL PLAIN.
THIS IS WHERE THE STRONGEST LOW AND MID LEVEL FRONTOGENETICAL
FORCING IS PROGGED TO BE ON THE MODELS. THIS IS ALSO THE AREA THAT
SPC HAS OUTLINED IN THE MESO-DISCUSSION AND WHERE HPC HAS PAINTED
THEIR HIGHEST POPS...ON THE ORDER OF 4 TO 6 INCHES...IN THEIR
INTERNAL SNOWFALL GRAPHICS.

SO IT LOOKS LIKE AROUND 2 INCHES FOR THE SRN AND CENTRAL NC
MTNS...MOST OF NE GA NORTH OF HARTWELL...MUCH OF THE NRN UPSTATE AND
THE NC PIEDMONT AROUND CHARLOTTE. LIGHTER AMOUNTS WILL FALL TO THE
NORTH...AND THE AREA OF 2 TO 4 INCH ACCUMS SHOULD STAY SOUTH OF THIS
LINE...IN THE AREA WHERE WE PRESENTLY HAVE A WARNING. BUT WE WILL
KEEP AN EYE ON THAT NRN BAND OF MODERATE PCPN.

EVEN THOUGH IT/S ONLY AN ADVISORY FOR PARTS OF THE AREA...CONDITIONS
WILL QUICKLY BECOME TREACHEROUS AS THE SNOW DEVELOPS ACROSS THE
REGION LATE THIS AFTN. TEMPS HAVE GENERALLY FALLEN TO AROUND
FREEZING AS THE SNOW HAS BEGUN...SO IT WILL START TO LAY ON
ROADS...PARTICULARLY ON BRIDGES...OVER THE NEXT FEW HOURS.

THE LOW WILL QUICKLY MOVE OUT TO SEA SAT MORNING. THE BACK EDGE OF
THE DEFORMATION ZONE SHOULD CLEAR THE EASTERN FRINGE OF THE FA
SOMETIME EARLY SAT MORNING...FOLLOWED BY A COOL DAY...BUT ONE WHERE
TEMPS SHOULD RISE ABOVE FREEZING OVER MOST OF THE NON-MOUNTAIN PARTS
OF THE FA. H8 TEMPS WILL FALL TO AROUND -10 DEG C ALONG THE TN
LINE...AND NW FLOW SNOW SHOWERS WILL PERSIST THROUGH THE DAY IN
THOSE LOCATIONS. THE SYNOPTIC FORCING IS QUITE WEAK...SO ADDITIONAL
SNOWFALL AMOUNTS SHOULD BE UNDER AND INCH.

&&

.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...
AS OF 230 PM FRIDAY...
THE FA WILL BE BTWN LOBES OF S/W ENERGY THAT WILL BE ROTATING ARND
AN UPR VORTEX INVOF THE CANADIAN MARITIMES ON SAT NGT AND SUNDAY.
THE UPSTREAM S/W WILL BE QUITE COMPACT...WITH A CLOSED LOW ARND
522-525 DAM...AS IT DIVES INTO THE MIDWEST STATES. MODELS ARE
TRENDING SLOWER WITH THIS FEATURE (AND THAT IS TO BE EXPECTED GIVEN
THE BLOCKING NATURE OF THE UPR PAT). THE BEST Q-VECTOR CONVERGENCE
ASSOCD W/ THE LOW WILL BE ON MONDAY...AND LOOKS TO BE STRONGEST JUST
N OF THE FA. OVERALL...MOISTURE WILL BE LIMITED TO A FRONTAL BAND
AHEAD OF A DRY SLOT...CROSSING THE AREA W-E DURING THE DAY ON
MONDAY. MODEL THICKNESSES SUPPORT MAINLY RAIN ACRS THE LWR
PIEDMONT...RAIN/SNOW MIX ACRS THE FOOTHILLS AND ADJACENT
PIEDMONT...AND ALL SNOW IN THE MTNS. QPF WILL NOT BE THAT GREAT...AS
THE GULF WILL BE CLOSED...AND THE SYS WILL BE FAST-MOVING. SO EXPECT
ONLY ADV LVL SNOW ACCUM (1-3") ACRS THE MTNS (ESP ALONG WEST-FACING
UPSLOPE RGNS) AND LTL IF ANY ELSW. TEMPS WILL START OUT IN THE 20S
SUNDAY...WITH HIGHS IN THE LWR-MID 40S (30S HIGH TERRAIN). SUN NGT
TEMPS WILL BE HELD IN CHECK DUE TO OVC CONDITIONS AND W/SWLY WAA
FLOW...AND RMN COLD MON WITH STRONG CAA BEHIND THE CDFNT DURING THE
AFTN.

&&

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
AS OF 145 PM FRIDAY...THE GLOBAL MODELS ARE IN GENERALLY GOOD
AGREEMENT IN DEPICTING A GRADUAL TRANSITION FROM DEEP NORTHWEST FLOW
OVER EARLY IN THE PERIOD...TO MORE OF A QUASI-ZONAL REGIME BY THE
END OF NEXT WEEK...AS THE EASTERN TROUGH STRETCHES/BROADENS. THIS
EVOLUTION WILL EVENTUALLY LEND ITSELF TO A WARMING TREND ACROSS THE
REGION BY THE END OF THE WEEK. HOWEVER...THE INTERIM PERIODS SHOULD
SEE A PROTRACTED NW FLOW SNOW EVENT...WITH UPSLOPE CLOUDS/SNOW
SHOWERS GENERALLY EXPECTED FROM MON EVENING THROUGH AT LEAST
THURSDAY. CHANCE POPS WILL BE CARRIED ALONG THE TENN BORDER TO
ACCOUNT FOR THIS. OTHERWISE...THE MEDIUM RANGE WILL BE MARKED BY
BELOW NORMAL TEMPS EARLY IN THE PERIOD...WARMING TO AROUND
CLIMATOLOGY OR EVEN WARMER BY THE END OF THE WEEK.

&&

.AVIATION /20Z FRIDAY THROUGH WEDNESDAY/...
AT KCLT...NO BIG SURPRISES WITH THE 12Z GUIDANCE PACKAGE IN REGARD
TO SNOW. STILL EXPECT SNOW TO BEGIN AT THE AIR FIELD IN THE 22-23Z
RANGE. PRECIP MAY BEGIN AS A MIXTURE OF RAIN/SNOW...BUT QUICKLY TURN
TO SNOW AS TEMP WET BULBS TOWARD FREEZING IN THE COLUMN AND AT THE
SURFACE. SNOW SHOULD BE LIGHT INITIALLY BUT PICK UP IN INTENSITY
AROUND 0100Z WITH AT LEAST IFR ON THE VSBY END AT THAT TIME. SHOULD
HAVE A PERIOD OF IFR/LIFR CIGS/VSBY IN 03Z-06Z RANGE AS BEST FORCING
MOVES THROUGH. SNOW ACCUMULATION EXPECTED TO BE AROUND 2 INCHES AT
THE AIR FIELD. SNOW EXPECTED TO END AROUND 06Z WITH CONDITIONS
IMPROVING TO VFR BY 11Z FOR THE SAT MORNING PUSH.

ELSEWHERE...SNOW WILL SPREAD ACROSS THE AREA IN GENERALLY A W TO E
FASHION LATE THIS AFTERNOON AND EVENING. VFR CONDITIONS WILL QUICKLY
DETERIORATE TO MVR AND THEN IFR. SHOULD HAVE ABOUT A 6 HOUR PERIOD
OF IFR CIGS/VSBY...EXCEPT KAVL MAY BE MORE ON THE LOWER END OF MVFR.
SNOW EXPECTED TO END FROM W TO E AND BE CLEAR FO THE FORECAST AREA
BY 08Z. VFR CONDITIONS EXPECTED ALL TAF SITES BY 12Z.

OUTLOOK...EXPECT VFR CONDITIONS SAT AFTERNOON THROUGH MOST OF THE
DAY TIME HOURS SUNDAY AS WEAK HIGH PRESSURE MOVES ACROSS THE REGION.
A CLIPPER SYSTEM WILL BRING A GOOD HANCE OF PRECIPITATION LATE
SUNDAY INTO MONDAY WITH A PERIOD OF MVFR/IFR SUNDAY NIGHT INTO
MONDAY. CONDITIONS SHOULD IMPROVE TO VFR E OF THE MOUNTAINS BY LATE
MONDAY AS DOWN SLOPE WINDS KICK IN BEHIND THE COLD FRONT. SOME
INTERMITTENT MVFR CONDITIONS MAY PERSIST AT KAVL THROUGH TUE IN NW
FLOW REGIME.

&&

.GSP WATCHES/WARNINGS/ADVISORIES...
GA...WINTER WEATHER ADVISORY UNTIL 6 AM EST SATURDAY FOR GAZ010-017-
     018-026-028.
     WINTER STORM WARNING UNTIL 6 AM EST SATURDAY FOR GAZ029.
NC...WINTER WEATHER ADVISORY UNTIL 6 AM EST SATURDAY FOR NCZ033-
     048>053-058-059-062>065-501>510.
     WINTER WEATHER ADVISORY UNTIL 6 AM EST SATURDAY FOR NCZ035>037-
     056-057-068>072.
     WINTER STORM WARNING UNTIL 6 AM EST SATURDAY FOR NCZ082.
SC...WINTER WEATHER ADVISORY UNTIL 6 AM EST SATURDAY FOR SCZ001>007-
     010.
     WINTER WEATHER ADVISORY UNTIL 6 AM EST SATURDAY FOR SCZ008.
     WINTER STORM WARNING UNTIL 6 AM EST SATURDAY FOR SCZ011>013-
     019.
     WINTER STORM WARNING UNTIL 6 AM EST SATURDAY FOR SCZ009-014.

&&

SYNOPSIS...JPT
NEAR TERM...MCAVOY
SHORT TERM...ARK
LONG TERM...JDL
AVIATION...LG

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
1140 AM EST FRI FEB 12 2010

GAZ010-017-018-026-028-NCZ033-048>053-058-059-062>065-501>510-
SCZ001>007-010-131645-
RABUN-HABERSHAM-STEPHENS-FRANKLIN-HART-AVERY-MADISON-YANCEY-MITCHELL-
SWAIN-HAYWOOD-BUNCOMBE-GRAHAM-NORTHERN JACKSON-MACON-
SOUTHERN JACKSON-TRANSYLVANIA-HENDERSON-CALDWELL MOUNTAINS-
GREATER CALDWELL-BURKE MOUNTAINS-GREATER BURKE-MCDOWELL MOUNTAINS-
EASTERN MCDOWELL-RUTHERFORD MOUNTAINS-GREATER RUTHERFORD-
POLK MOUNTAINS-EASTERN POLK-OCONEE MOUNTAINS-PICKENS MOUNTAINS-
GREENVILLE MOUNTAINS-GREATER OCONEE-GREATER PICKENS-
GREATER GREENVILLE-SPARTANBURG-ANDERSON-
1140 AM EST FRI FEB 12 2010

...WINTER WEATHER ADVISORY IN EFFECT UNTIL 6 AM EST SATURDAY...

THIS HAZARDOUS WEATHER OUTLOOK IS FOR NORTHEAST GEORGIA...WESTERN
NORTH CAROLINA AND UPSTATE SOUTH CAROLINA.

.DAY ONE...THIS AFTERNOON AND TONIGHT.

PLEASE LISTEN TO NOAA WEATHER RADIO OR GO TO WEATHER.GOV ON THE
INTERNET FOR MORE INFORMATION ABOUT THE FOLLOWING HAZARDS.

   WINTER WEATHER ADVISORY.

.DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY.

ANOTHER STORM SYSTEM WILL SWING THROUGH THE REGION SUNDAY NIGHT...
PERHAPS RESULTING IN A PERIOD OF ACCUMULATION SNOW SHOWERS.

.SPOTTER INFORMATION STATEMENT...

NONE.

NCZ035>037-056-057-068>072-SCZ008-131645-
ALEXANDER-IREDELL-DAVIE-CATAWBA-ROWAN-CLEVELAND-LINCOLN-GASTON-
MECKLENBURG-CABARRUS-CHEROKEE-
1140 AM EST FRI FEB 12 2010

...WINTER WEATHER ADVISORY IN EFFECT FROM 5 PM THIS AFTERNOON TO
6 AM EST SATURDAY...

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PIEDMONT NORTH
CAROLINA...WESTERN NORTH CAROLINA AND UPSTATE SOUTH CAROLINA.

.DAY ONE...THIS AFTERNOON AND TONIGHT.

PLEASE LISTEN TO NOAA WEATHER RADIO OR GO TO WEATHER.GOV ON THE
INTERNET FOR MORE INFORMATION ABOUT THE FOLLOWING HAZARDS.

   WINTER WEATHER ADVISORY.

.DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY.

ANOTHER STORM SYSTEM WILL SWING THROUGH THE REGION SUNDAY NIGHT...
PERHAPS RESULTING IN A PERIOD OF ACCUMULATION SNOW SHOWERS.

.SPOTTER INFORMATION STATEMENT...

NONE.

NCZ082-SCZ009-014-131645-
UNION NC-YORK-CHESTER-
1140 AM EST FRI FEB 12 2010

...WINTER STORM WARNING IN EFFECT FROM 5 PM THIS AFTERNOON TO 6 AM
EST SATURDAY...

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PIEDMONT NORTH CAROLINA AND
UPSTATE SOUTH CAROLINA.

.DAY ONE...THIS AFTERNOON AND TONIGHT.

PLEASE LISTEN TO NOAA WEATHER RADIO OR GO TO WEATHER.GOV ON THE
INTERNET FOR MORE INFORMATION ABOUT THE FOLLOWING HAZARDS.

   WINTER STORM WARNING.

.DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY.

ANOTHER STORM SYSTEM WILL SWING THROUGH THE REGION SUNDAY NIGHT...
PERHAPS RESULTING IN A PERIOD OF ACCUMULATION SNOW SHOWERS.

.SPOTTER INFORMATION STATEMENT...

NONE.

GAZ029-SCZ011>013-019-131645-
ELBERT-ABBEVILLE-LAURENS-UNION SC-GREENWOOD-
1140 AM EST FRI FEB 12 2010

...WINTER STORM WARNING IN EFFECT UNTIL 6 AM EST SATURDAY...

THIS HAZARDOUS WEATHER OUTLOOK IS FOR NORTHEAST GEORGIA AND UPSTATE
SOUTH CAROLINA.

.DAY ONE...THIS AFTERNOON AND TONIGHT.

PLEASE LISTEN TO NOAA WEATHER RADIO OR GO TO WEATHER.GOV ON THE
INTERNET FOR MORE INFORMATION ABOUT THE FOLLOWING HAZARDS.

   WINTER STORM WARNING.

.DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY.

ANOTHER STORM SYSTEM WILL SWING THROUGH THE REGION SUNDAY NIGHT...
PERHAPS RESULTING IN A PERIOD OF ACCUMULATION SNOW SHOWERS.

.SPOTTER INFORMATION STATEMENT...

NONE.

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