Winter Weather in Georgia, March 1, 2009

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
1243 PM EST SUN MAR 1 2009

.SYNOPSIS...
A COMPLEX LOW PRESSURE SYSTEM...ASSOCIATED WITH A STRONG UPPER
LEVEL DISTURBANCE...WILL AFFECT THE FORECAST AREA THROUGH EARLY
MONDAY. BEHIND THIS SYSTEM...HIGH PRESSURE WILL BUILD IN FROM THE
NORTH AND REMAIN IN PLACE THROUGH MID WEEK.

&&

.NEAR TERM /THROUGH TONIGHT/...
WITH TEMPS RANGING FROM THE M30S-L40S ACROSS THE PIEDMONT AND AROUND
FREEZING AT HIGHER MTN ELEVS...FCST IS ON TRACK. STILL EXPECT
GRADUAL COOLING THIS AFTN WITH WINTRY MIX PICKING UP FIRST IN THE
N-NE..SPREADING S AND W...TO FINALLY BECOME SNOW BY THIS EVE ACROSS
THE CWA. TWEAKED GRIDS WITH LATEST GUIDANCE/TRENDS AND WILL SEND
UPDATED PRODUCTS SHORTLY.

PREVIOUS DISCUSSION...A QUICK VERY NEAR TERM UPDATE TO ACCOUNT FOR
THUNDER OBSERVED ALONG AND EAST OF I-85 EARLY THIS MORNING. HAVE
TAKEN THE OPPORTUNITY TO ADDRESS TEMP/DEWPT TRENDS ACROSS THE
FOOTHILLS AND NC PIEDMONT. NEAR FREEZING TEMPS COULD BRING A BRIEF
MIX EARLY ON BEFORE A CHANGEOVER TO RAIN FOR A FEW HOURS. NEW NAM
WAS CONSULTED FOR MINOR CHANGES TO PRECIP TYPE DISTRIBUTION
THROUGHOUT THE DAY...BUT NO REAL CHANGE IN THINKING WITH REGARD TO
PROBABILITY OF MULTIPLE P-TYPE CHANGES DEPENDING ON PRECIP
INTENSITY. NEW QPF GUIDANCE WAS TAKEN INTO ACCOUNT IN THE
FORMULATION OF SNOW AMOUNT FORECAST. MINOR ALTERATIONS WERE
MADE...UP OR DOWN AN INCH OR SO. BEST LIKELIHOOD OF HEAVY SNOW
REMAINS ALONG AND S OF I-85 THIS EVENING...OR WHERE THE DEFORMATION
ZONE ULTIMATELY SETS UP.

MODELS AGREE THAT CLOSED UPPER LOW WILL CONTINUE TO MOVE EASTWARD
ACROSS THE SOUTHEAST TODAY AND UP THE MID ATLANTIC COAST TONIGHT...
ORGANIZING A SURFACE LOW ALONG THE CAROLINA COAST. ALREADY SEEING
NORTHWARD TRANSPORT OF MOISTURE AND PRECIP AHEAD OF THE UPPER SYSTEM
IN A DEVELOPING WARM CONVEYOR BELT EARLY THIS MORNING...SO NO NEED
TO QUIBBLE ABOUT PRECIP CHANCES. CATEGORICAL MOST PLACES WITH
EXCEPTION OF TN BORDER WHICH WILL HAVE A BIT OF A RAIN SHADOW.
WHAT IS NOT CLEAR IS EXACTLY WHEN PRECIP WILL CHANGE OVER. FORECAST
SOUNDINGS SHOW NEARLY ISOTHERMAL LAPSE RATES FROM MID MORNING ONWARD
EAST OF THE MTNS...WITH ONLY A RELATIVELY WARM BOUNDARY LAYER TO
PREVENT MUCH OF THIS PRECIP FROM BEING A WET SNOW. IN THESE
SITUATIONS...DYNAMIC COOLING CAN PLAY A BIG ROLE IN BRINGING THE
SNOW ALL THE WAY DOWN TO THE GROUND IF THE PRECIPITATION RATE IS
HIGH ENOUGH. RIGHT NOW...THE FORECAST FROM MID MORNING ONWARD WILL
FEATURE AN EXPANDING AREA OF RAIN OR SNOW FROM NORTH TO SOUTH...
EAST OF THE MTNS. MULTIPLE TRANSITIONS BETWEEN RAIN AND WET SNOW ARE
EXPECTED. AS LONG AS PRECIP IS LIGHT...IT WILL BE LIQUID...BUT IF
HEAVIER SHOWERS DEVELOP IT WILL CHANGE TO SNOW. THIS COULD
SIGNIFICANTLY BUMP UP ACCUMULATIONS IN SOME SPOTS WHERE PRECIP IS
HEAVIEST. MEANWHILE...ACROSS THE NRN MTNS AND FRENCH BROAD VALLEY
THE SNOW LEVEL WILL COME DOWN INTO THE VALLEYS BY MIDDAY. PRECIP
WILL CHANGE OVER LAST ACROSS THE FAR SW PART OF NC WHERE TEMPS WILL
BE ELEVATED.

WHAT IS MORE KNOWN IS THAT DEVELOPMENT OF UPGLIDE IN THE COOL
CONVEYOR BELT AND THE MOVEMENT OF A DEFORMATION ZONE WILL BRING
ADDITIONAL PRECIP ACROSS THE REGION LATE THIS AFTERNOON AND TONIGHT.
THE PROBLEM IS EXACTLY WHERE THIS FEATURE WILL SET UP AS THE LOW
ORGANIZES. A COMPROMISE OF THE MODEL SOLUTIONS SUGGESTS THE MOST
LIKELY PLACE WILL BE ESSENTIALLY IN A BAND FROM ELBERTON AND
GREENWOOD NORTHEAST ACROSS THE FOOTHILLS AND PIEDMONT OF THE
CAROLINAS. BY THE TIME THIS HAPPENS...MID LEVELS SHOULD COOL ENOUGH
SUCH THAT MOST PRECIP AFTER SUNSET WILL BE ALL SNOW. WITH THE
EXPECTED PRECIP AMOUNTS...THAT TRANSLATES ROUGHLY TO A 3-6 INCH
SNOWFALL ESSENTIALLY ALONG AND S OF I-85 MAINLY TONIGHT.

SO HERES THE RUNDOWN. WATCH WILL BE UPGRADED TO A WARNING ACROSS THE
NC FOOTHILLS/PIEDMONT...AND E OF A LINE FROM HARTWELL TO ANDERSON
AND GREENVILLE...BECAUSE OF HEAVY SNOW TONIGHT IN DEFORMATION ZONE.
WARNING WILL BEGIN AT NOON IN CASE SOME SPOTS CHANGE OVER EARLY WITH
INTENSE PRECIP.  THE NRN MTNS AND UPPER FRENCH BROAD VALLEY GET A
WARNING AS WELL BECAUSE OF EARLY ONSET AND HIGH ELEVATION SNOW
CONCERNS THROUGH THE DAY. THE REST OF THE NC MTNS GET AN ADVISORY
FOR NOW BECAUSE IT APPEARS THEY WILL MISS THE BEST PRECIP IN THE
DEFORMATION ZONE AND WILL BE DRY SLOTTED EARLIER. THE WRN UPSTATE
AND REST OF NE GEORGIA ALSO GETS AND ADVISORY STARTING AT
NOON...EVEN THO FORECAST SNOW IS MINIMAL...ONLY BECAUSE OF
UNCERTAINTY ABOUT WHERE DEFORMATION ZONE WILL SET UP. THINK IT
BETTER TO HAVE SOMETHING OUT ACROSS ENTIRE FORECAST AREA AT THIS
POINT...EVEN THOUGH SOME LOCATIONS WILL MISS OUT.

&&

.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
AT 300 AM EST...THE MODELS SHOW THE UPPER TROUGH AXIS BETWEEN OUR
AREA AND THE COAST MONDAY MORNING...AND REACHES THE COAST BY
EVENING. NORTHWEST FLOW ALOFT BEHIND THE TROUGH REMAINS OVER OUR
AREA THROUGH TUESDAY NIGHT...WITH HEIGHTS RISING AS AN UPPER RIDGE
SLOWLY CROSS THE ROCKIES AND MOVES INTO THE PLAINS. MOIST NORTHWEST
FLOW STILL REMAINS IN THE NORTHERN NC MOUNTAINS EARLY MONDAY
MORNING... BUT ONLY ENOUGH TO SUPPORT ISOLATED SNOW SHOWERS UNTIL
MIDDAY. MOISTURE DECREASED ENOUGH TO END SNOW SHOWERS IN THE
AFTERNOON... THOUGH CLOUD COVER SHOULD REMAIN ELEVATED UNTIL
EVENING. WINDS WILL BE RATHER UP DURING THE DAY IN A TIGHT
GRADIENT...THEN WILL GRADUALLY DIMINISH MONDAY NIGHT. TUESDAY
FEATURES A DRY RIDGE OVER THE AREA. ON TUESDAY NIGHT SOME MID AD
UPPER AND UPPER LEVEL MOISTURE MOVES EAST OVER THE BACK SIDE OF THE
RIDGE...RESULTING IN MODEST CLOUD COVER.

TEMPERATURES WILL BE MORE THAN 15 DEGREES BELOW NORMAL MONDAY AND
MONDAY NIGHT AS COLD AIR MOVES IN BEHIND THE DEPARTING STORM...WITH
WIND CHILL VALUES FALLING TO THE LOW SINGLE NUMBERS IN THE MOUNTAINS
MONDAY NIGHT...AND THE TEENS IN MUCH OF THE FOOTHILLS AND PIEDMONT.
TEMPERATURES TUESDAY AND TUESDAY NIGHT ARE STILL MORE THAN 10
DEGREES BELOW NORMAL...AND NOT EVEN UP TO OUR MID WINTER NORMALS.

&&

.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
AS OF 210 AM SUNDAY...BOTH THE GFS AND ECMWF SHOW A TRANQUIL WEATHER
PATTERN WITH A WARMING TREND FROM WEDNESDAY THROUGH THE START OF
NEXT WEEKEND.  BOTH MODELS HAVE WEAK SYSTEMS SKIRTING THE MOUNTAINS
LATE IN THE WEEK...UNTIL THE EC TAKES A STRONG SHORTWAVE AND SURFACE
COLD FRONT RIGHT AT US...ARRIVING NEXT SUNDAY MORNING.  UNTIL NEXT
SUNDAY HOWEVER NOTHING REALLY HAPPENING ACROSS OUR FORECAST AREA BUT
WARMING.  THE TROUGH MOVES OFF THE EAST COAST WEDNESDAY...THEN THE
GFS BRINGS IN A FAIRLY SIGNIFICANT UPPER RIDGE ACROSS THE
SOUTHEAST.  THE EC CONTRASTS A BIT WITH ZONAL FLOW THURSDAY THROUGH
SATURDAY.  THE EC HAS QPF VALUES OF A HALF INCH TO THREE QUARTER OF
AN INCH GETTING INTO THE NC MOUNTAINS AT 12Z NEXT SUNDAY.  I WOULD
RATHER HOLD OFF ON STARTING PRECIP FOR THE MOUNTAINS UNTIL THE NEXT
RUN AT LEAST TO SEE IF THE GFS AND EC CAN AGREE.  THEY ARE CERTAINLY
AT ODDS NOW FOR THE PERIOD A WEEK AWAY.

&&

.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
KCLT AND ELSEWHERE...MVFR...TEMPO IFR WITH GUSTY NE WINDS AS WINTER
STORM TAKES SHAPE. EXPECT SNOW TO MIX WITH RAIN THEN TURN TO ALL
SNOW BY MID-LATE AFTN WITH IFR THEN THRU THE EVE. EXPECT ISOLD TSTMS
AND HAVE CB CLOUDS IN TAFS FOR NOW. WINDS SWING MORE N AS WELL. BEST
FORCING MOVES E AFTER MIDNIGHT AND CIG/VSBY SHOULD IMPROVE TO VFR
OVERNIGHT. N WINDS STAY UP AROUND 10 KTS AROUND DAYBREAK...HIGHER AT
KAVL...WHICH SHOULD KEEP VSBY UP.

OUTLOOK...OUTSIDE OF PSBL FOG TUE MRNG...VFR AS HIGH PRESSURE BUILDS
IN.

&&

.GSP WATCHES/WARNINGS/ADVISORIES...
GA...WINTER STORM WARNING UNTIL 7 AM EST MONDAY FOR GAZ028-029.
     WINTER WEATHER ADVISORY UNTIL 7 AM EST MONDAY FOR GAZ010-017-
     018-026.
NC...WINTER STORM WARNING UNTIL 7 AM EST MONDAY FOR NCZ033-035>037-
     049-050-053-056-057-065-068>072-082-501>510.
     WINTER WEATHER ADVISORY UNTIL 7 AM EST MONDAY FOR NCZ048-051-
     052-058-059-062>064.
SC...WINTER STORM WARNING UNTIL 7 AM EST MONDAY FOR SCZ003-006>014-
     019.
     WINTER WEATHER ADVISORY UNTIL 7 AM EST MONDAY FOR SCZ001-002-
     004-005.

&&

SYNOPSIS...DEO
NEAR TERM...PM/RB
SHORT TERM...JAT
LONG TERM...DEO
AVIATION...RB

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
520 AM EST SUN MAR 1 2009

GAZ010-017-018-026-SCZ001-002-004-005-021030-
RABUN-HABERSHAM-STEPHENS-FRANKLIN-OCONEE MOUNTAINS-PICKENS MOUNTAINS-
GREATER OCONEE-GREATER PICKENS-
520 AM EST SUN MAR 1 2009

...WINTER WEATHER ADVISORY IN EFFECT FROM NOON TODAY TO 7 AM EST
MONDAY...

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

.DAY ONE...TODAY 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...MONDAY THROUGH SATURDAY.

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

   WINTER WEATHER ADVISORY.

.SPOTTER INFORMATION STATEMENT...

WEATHER SPOTTERS ARE ENCOURAGED TO REPORT SNOW AND ICE ACCUMULATIONS
TO THE NATIONAL WEATHER SERVICE.

GAZ028-029-NCZ035>037-056-057-068>072-082-501>510-SCZ003-006>014-019-
021030-
HART-ELBERT-ALEXANDER-IREDELL-DAVIE-CATAWBA-ROWAN-CLEVELAND-LINCOLN-
GASTON-MECKLENBURG-CABARRUS-UNION NC-CALDWELL MOUNTAINS-
GREATER CALDWELL-BURKE MOUNTAINS-GREATER BURKE-MCDOWELL MOUNTAINS-
EASTERN MCDOWELL-RUTHERFORD MOUNTAINS-GREATER RUTHERFORD-
POLK MOUNTAINS-EASTERN POLK-GREENVILLE MOUNTAINS-GREATER GREENVILLE-
SPARTANBURG-CHEROKEE-YORK-ANDERSON-ABBEVILLE-LAURENS-UNION SC-
CHESTER-GREENWOOD-
520 AM EST SUN MAR 1 2009

...WINTER STORM WARNING IN EFFECT FROM NOON TODAY TO 7 AM EST
MONDAY...

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

.DAY ONE...TODAY 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...MONDAY THROUGH SATURDAY.

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

   WINTER STORM WARNING.

.SPOTTER INFORMATION STATEMENT...

WEATHER SPOTTERS ARE ENCOURAGED TO REPORT SNOW AND ICE ACCUMULATIONS
TO THE NATIONAL WEATHER SERVICE.

NCZ048-051-052-058-059-062>064-021030-
MADISON-SWAIN-HAYWOOD-GRAHAM-NORTHERN JACKSON-MACON-SOUTHERN JACKSON-
TRANSYLVANIA-
520 AM EST SUN MAR 1 2009

...WINTER WEATHER ADVISORY IN EFFECT UNTIL 7 AM EST MONDAY...

THIS HAZARDOUS WEATHER OUTLOOK IS FOR WESTERN NORTH CAROLINA.

.DAY ONE...TODAY 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...MONDAY THROUGH SATURDAY.

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

   WINTER WEATHER ADVISORY.

.SPOTTER INFORMATION STATEMENT...

WEATHER SPOTTERS ARE ENCOURAGED TO REPORT SNOW AND ICE ACCUMULATIONS
TO THE NATIONAL WEATHER SERVICE.

NCZ033-049-050-053-065-021030-
AVERY-YANCEY-MITCHELL-BUNCOMBE-HENDERSON-
520 AM EST SUN MAR 1 2009

...WINTER STORM WARNING IN EFFECT UNTIL 7 AM EST MONDAY...

THIS HAZARDOUS WEATHER OUTLOOK IS FOR WESTERN NORTH CAROLINA.

.DAY ONE...TODAY 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...MONDAY THROUGH SATURDAY.

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

   WINTER STORM WARNING.

.SPOTTER INFORMATION STATEMENT...

WEATHER SPOTTERS ARE ENCOURAGED TO REPORT SNOW AND ICE ACCUMULATIONS
TO THE NATIONAL WEATHER SERVICE.