Red Flag Warning 13, NWS Greenville-Spartanburg, SC

000 
WWUS82 KGSP 140023
RFWGSP

RED FLAG WARNING
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
823 PM EDT FRI APR 13 2007

GAZ010-017-018-026-028-029-140130-
/O.EXP.KGSP.FW.W.0013.000000T0000Z-070414T0000Z/
RABUN-HABERSHAM-STEPHENS-FRANKLIN-HART-ELBERT-
823 PM EDT FRI APR 13 2007

...RED FLAG WARNING HAS EXPIRED...

THE RED FLAG WARNING IS NO LONGER IN EFFECT. 

RELATIVE HUMIDITY OVER THE WARNED AREA ROSE ABOVE 25 PERCENT SO
THE WARNING WAS ALLOWED TO EXPIRE ON TIME.

$$

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
1115 AM EDT FRI APR 13 2007

.SHORT TERM /REST OF TODAY/...
REGIONAL RADARS SHOW AREA OF PRECIP OVER TN MOVING EAST TOWARD
OUR AREA. ALTHOUGH THE ECHOES ARE IMPRESSIVE...OBS SHOWING LITTLE
IF ANY PRECIP REACHING THE GROUND. IN FACT...OBS SHOWING LITTLE IF
ANY LOW CLOUDS WITH THIS AREA. 12Z RAOBS AND UPPER AIR CHARTS SHOW
LOW LEVELS STILL QUITE DRY. 12Z RUC AND NAM ARE DRY WHILE 06Z GFS
BRINGS PRECIP INTO THE MOUNTAINS. GFS LOOKS BETTER REGARDING
COVERAGE OF ECHOES AND CLOUDS...BUT OVERDONE WITH PRECIP AMOUNTS.
THEREFORE WILL LOWER MOUNTAIN POP TO SLIGHT CHC...BUT INCLUDE
SCATTERED SPRINKLES SINCE SOME OF THIS PRECIP WILL REACH THE
GROUND...BUT CHANCES OF MEASURABLE PRECIP QUITE LOW. GIVEN THE
OBSERVED TEMPS AND LIKELY BRIGHT BANDING...CANNOT RULE OUT SOME
SLEET FALLING ALONG WITH THE RAIN...ESPECIALLY IN THE HIGHER
ELEVATIONS. SHOULD REMAIN BREEZY THROUGH EARLY AFTERNOON AND LEFT
FORECAST HIGHS MOSTLY AS IS.

ELSEWHERE...EXPECT MID AND HIGH LEVEL CLOUDS TO MOVE IN THROUGH
THE DAY AFTER A FULL SUN MORNING. OBSERVED THICKNESS SCHEME TEMPS
RANGE FROM 63 NORTH TO 75 SOUTH. CURRENT FORECAST IS ACTUALLY
PRETTY CLOSE TO THESE NUMBERS...SO ONLY SOME MINOR ADJUSTMENTS
NEEDED. BRIEF WIND GUSTS THIS MORNING SHOULD MIX OUT BY AFTERNOON.
THEREFORE...ONLY MINOR CHANGES OUTSIDE OF THE MOUNTAINS.

&&

.FIRE WEATHER...
SUBSIDENCE INVERSION ON THE 12Z FFC RAOB QUITE STRONG. THIS WILL
LIMIT MIXING EVEN WITH HIGHS IN THE LOWER 70S. NOT QUITE AS DRY AS
GSO...BUT CANNOT BE CONSIDERED MOIST. MODELS INSIST DEW POINTS
WILL ACTUALLY RISE THROUGH THE DAY BUT JUST CANNOT SEE THAT
HAPPENING. IN FACT...RH ALONG THE SAVANNAH RIVER VALLEY ALREADY 30
PERCENT OR LESS. WILL RE-ISSUE THE RED FLAG WARNING FOR NE GA.
12Z GSO RAOB QUITE DRY IN THE LOW AND MID LEVELS. EXPECT DEW
POINTS TO DROP TODAY OVER NC FOOTHILLS PIEDMONT WITH DECENT MIXING
AND NORTHWESTERLY FLOW. NC MTNS SHOULD NOT SEE THE PRECIPITOUS
TUMBLE OF YESTERDAY WITH MOISTENING MID LEVELS. UPSTATE WILL SEE
RH BELOW 25 PERCENT AS WELL...BUT WINDS WILL NOT REACH RED FLAG
OVER NC OR SC.

&&

.PREV DISCUSSION...
/ISSUED 304 AM EDT FRI APR 13 2007/

SHORT TERM /TODAY THROUGH SUNDAY/...
MAIN FORECAST CHALLENGE FOR TODAY IS WHETHER OR NOT THE NC MTNS WILL
SEE ANY RAINFALL AS A WARM FRONT LIFTS ACROSS THE REGION. THE GFS IS
BASICALLY DRY...WHILE THE OPERATIONAL RUN OF THE NAM ACTUALLY
GENERATES SOME HEALTHY QPF ACROSS THE SOUTHWEST NC MTNS. THIS SEEMS
A BIT OVERDONE CONSIDERING THE GENERALLY WEAK...MID-LEVEL FORCING...
AND AS WE ARE STILL IN THE DRY AIRMASS ON THE SOUTHWEST SIDE OF THE
STRONG UPPER LOW WHICH IS SLOWLY LIFTING INTO SOUTHERN CANADA.
LOOKING AT THE SREF...THE MEAN POP ONLY BRIEFLY TOUCHES 50 PERCENT
RIGHT ALONG THE TN BORDER LATE THIS AFTN...WITH POPS FOR THE MOST
PART AROUND 30 PERCENT ACROSS THE NC MTNS AFTER 18 UTC. THIS SEEMS
LIKE A GOOD COMPROMISE AND IS WHAT I/VE TRIED TO DO WITH MY GRIDS.
IT MAY BE THAT SOME SPRINKLES MAKE IT A WAYS EAST OF THE MTNS LATER
TODAY...BUT THE ODDS OF ACCUMULATING PCPN ARE QUITE LOW. THUS...I
WILL MENTION A SLIGHT CHANCE OF RAIN IN ALL ZONES WHERE I HAVE THAT
KIND OF POP...SOMETHING WE DON/T ALWAYS DO.

AT THIS POINT I/M PLANNING TO CANCEL THE RED FLAG WARNING FOR NE GA
AS DEWPOINTS DON/T LOOK TO GET DOWN TO 25 PERCENT FOR EVEN ONE
HOUR...MUCH LESS THE 4 WE NEED TO VERIFY A WARNING. NOR DO OUR WIND
GUSTS LOOK SUFFICIENT FOR A WARNING.

A TOKEN CHANCE POP WILL BE MAINTAINED ACROSS PORTIONS OF THE NC MTNS
DURING THE EARLY PORTION OF THE 2ND PERIOD...AS WARM FRONTAL
MOISTURE BAND REMAINS OVER THE AREA. HOWEVER...THE INTERESTING
WEATHER WILL HOLD OFF UNTIL SATURDAY AFTERNOON...AS A VERY DYNAMIC
UPPER LEVEL STORM SYSTEM AND ASSOCIATED POWERFUL COLD FRONT APPROACH
THE REGION. THE GFS IS SEVERAL HOURS FASTER THAN THE NAM IN BRINGING
THE BEST DEEP LAYER FORCING/QPF INTO THE REGION LATE SAT AFTERNOON.
THE 12/21Z SREF AGREES QUITE WELL WITH THE GFS...SO THE GFS HAS BEEN
FOLLOWED CLOSELY IN TERMS OF TIMING. HOWEVER...THIS NECESSITATES
SCALING BACK POPS JUST A BIT FOR SAT AFTERNOON...AS IT APPEARS
CATEGORICAL COVERAGE OF PRECIPITATION SHOULD REMAIN CONFINED TO THE
MTNS AND SAVANNAH RIVER VALLEY DURING THIS TIME.

WITH THE VERY DYNAMIC NATURE OF THE SYSTEM...WIND FIELDS WILL BE
QUITE IMPRESSIVE...MORE THAN ADEQUATE FOR SEVERE THUNDERSTORMS.
HOWEVER...INSTABILITY WILL BE AT A PREMIUM. IN FACT...THE 12/21Z
SREF INDICATES THAT IT IS UNLIKELY THAT CAPE VALUES WILL EVEN EXCEED
250 J/KG. HOWEVER...I SUSPECT THERE WILL BE SOME DEGREE OF WEAK
INSTABILITY...AND WITH THE STRONG LINEAR FORCING EXPECTED SAT
AFTERNOON AND EVENING...CHANCES ARE QUITE HIGH THAT WE WILL SEE
DEVELOPMENT OF A LOW-TOPPED QUASI-LINEAR CONVECTIVE SYSTEM WITH
EMBEDDED ISOLATED...BRIEF TORNADOES.

DEEP FORCING WILL SHIFT EAST ACROSS THE AREA DURING THE EVENING...
WITH THE MAIN BAND OF PRECIP EXPECTED TO BE EAST OF OUR ZONES PRIOR
TO 12Z SUNDAY. HOWEVER...THERE WILL BE WRAP AROUND/DEFORMATION ZONE
PRECIP INTO EARLY SUNDAY MORNING...MAINLY AFFECTING THE MTNS.
FREEZING LEVELS WILL DROP RAPIDLY AS THE COLD FRONT CROSSES THE AREA
SUNDAY MORNING. WITH STRONG NORTHWEST FLOW AND PLENTIFUL LOW LEVEL
MOISTURE IMPACTING THE SOUTHERN APPALACHIANS SUNDAY...WE COULD SEE
ANOTHER LATE SEASON NORTHWEST FLOW SNOW EVENT. HOWEVER...THE
THERMODYNAMIC SETUP DOESN/T LOOK QUITE AS GOOD IN THIS CASE AS IT
DID IN LAST WEEK/S QUASI-SURPRISE. IN FACT...WIND MAY BE THE LARGER
CONCERN...AS STRONG COLD ADVECTION AND A 50-55 KT LLJ COULD RESULT
IN AT LEAST ADVISORY LEVEL WINDS ACROSS THE MTNS SUNDAY.

LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
BREEZY CONDITIONS WILL CONTINUE INTO EARLY MONDAY ACROSS THE
AREA...WITH SNOW SHOWERS CONTINUING ACROSS THE MTNS SUNDAY NIGHT.
OTHERWISE...THE UNSEASONABLY COOL AIRMASS THAT IS EXPECTED TO AFFECT
THE REGION EARLY NEXT WEEK SHOULDN/T BE AS STUBBORN TO RELENT AS
LAST WEEK/S HISTORICALLY COOL AIRMASS. THE PATTERN WILL BE QUITE
PROGRESSIVE NEXT WEEK...WITH THE EASTERN TROUGH MOVING QUICKLY OFF
THE COAST BY TUESDAY...AND ANOTHER AREA OF LOW PRESSURE MOVES INTO
THE REGION FROM THE SOUTHERN PLAINS. PER THE LATEST MODEL DATA...
THIS LATTER FEATURE DOESN/T HAVE THE MAKINGS OF A BIG PRECIP
PRODUCER ACROSS OUR AREA. NEVERTHELESS...WE WILL MAINTAIN SMALL
CHANCE POPS IN THE WED-THU PERIOD.

AVIATION /07Z-06Z/...
VFR TAFS THE NEXT 24 HRS. WINDS THIS MORNING WILL BE NORTHWEST AT
ALL SITES. KAND WILL TURN OUT OF THE WEST SOUTHWEST BY MID MORNING
AS STAY THAT WAY THROUGH THE DAY. KAVL WILL STAY OUT OF THE
NORTHWEST WITH A FEW GUSTS TO 25 KTS. THE REST OF THE SITES WILL
GRADUALLY SEE WINDS BECOME LIGHT AND VARIABLE INTO THE AFTERNOON
HOURS. CIGS SHOULD FALL AT KAVL LATER TDA...AND THERE IS A SLIGHT
CHANCE THAT SOME LIGHT SPRINKLES WILL DEVELOP...BUT IT APPEARS THAT
MOST OF THE PCPN WITH THE WARM FRONT THAT LIFTS ACROSS THE MOUNTAINS
LATER TDA WILL STAY WEST OF THE AIRPORT.

&&

.GSP WATCHES/WARNINGS/ADVISORIES...
GA...RED FLAG WARNING UNTIL 8 PM EDT THIS EVENING FOR GAZ010-017-
     018-026-028-029.

NC...NONE.
SC...NONE.
&&

SHORT TERM...RWH
FIRE WEATHER...RWH

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
535 AM EDT FRI APR 13 2007

NCZ033-048>053-058-059-062>065-501-503-505-507-509-140945-
AVERY-MADISON-YANCEY-MITCHELL-SWAIN-HAYWOOD-BUNCOMBE-GRAHAM-
NORTHERN JACKSON-MACON-SOUTHERN JACKSON-TRANSYLVANIA-HENDERSON-
CALDWELL MOUNTAINS-BURKE MOUNTAINS-MCDOWELL MOUNTAINS-
RUTHERFORD MOUNTAINS-POLK MOUNTAINS-
535 AM EDT FRI APR 13 2007

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF WESTERN NORTH
CAROLINA.

.DAY ONE...TODAY AND TONIGHT

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY

A POWERFUL STORM SYSTEM AND ASSOCIATED STRONG COLD FRONT WILL
BRING WIDESPREAD RAIN WITH EMBEDDED THUNDERSTORMS TO THE MOUNTAINS
BY LATE SATURDAY AFTERNOON. A FEW SEVERE STORMS WILL BE POSSIBLE
SATURDAY AFTERNOON AND EVENING. HEAVY RAINFALL CAN ALSO BE
EXPECTED...ESPECIALLY ALONG THE SOUTHERN ESCARPMENT.

NORTHWEST WINDS WILL BECOME STRONG AND GUSTY BEHIND THE FRONT ON
SUNDAY AND SUNDAY NIGHT. GUSTS AS HIGH AS 50 MPH WILL BE
POSSIBLE...ESPECIALLY IN THE HIGHER ELEVATIONS. AS SNOW LEVELS
FALL SUNDAY INTO SUNDAY NIGHT...SCATTERED TO NUMEROUS SNOW SHOWERS
ARE EXPECTED TO DEVELOP ACROSS THE MOUNTAINS SUNDAY NIGHT AND
CONTINUE INTO EARLY MONDAY. ACCUMULATING SNOWFALL MAY OCCUR...
ESPECIALLY IN THE HIGHER ELEVATIONS ALONG THE TENNESSEE BORDER.

FREEZING TEMPERATURES ARE EXPECTED ACROSS MUCH OF THE AREA MONDAY
MORNING.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION WILL NOT BE NEEDED.

GAZ010-017-018-026-028-029-NCZ035>037-056-057-068>072-082-502-504-
506-508-510-SCZ001>014-019-140945-
RABUN-HABERSHAM-STEPHENS-FRANKLIN-HART-ELBERT-ALEXANDER-IREDELL-
DAVIE-CATAWBA-ROWAN-CLEVELAND-LINCOLN-GASTON-MECKLENBURG-CABARRUS-
UNION NC-GREATER CALDWELL-GREATER BURKE-EASTERN MCDOWELL-
GREATER RUTHERFORD-EASTERN POLK-OCONEE MOUNTAINS-
PICKENS MOUNTAINS-GREENVILLE MOUNTAINS-GREATER OCONEE-
GREATER PICKENS-GREATER GREENVILLE-SPARTANBURG-CHEROKEE-YORK-
ANDERSON-ABBEVILLE-LAURENS-UNION SC-CHESTER-GREENWOOD-
535 AM EDT FRI APR 13 2007

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

.DAY ONE...TODAY AND TONIGHT

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY

A POWERFUL STORM SYSTEM AND ASSOCIATED STRONG COLD FRONT WILL
BRING WIDESPREAD RAIN WITH EMBEDDED THUNDERSTORMS TO THE PIEDMONT
AND FOOTHILLS BY LATE SATURDAY EVENING. SEVERE THUNDERSTORMS
PRODUCING LARGE HAIL...DAMAGING WINDS...AND ISOLATED TORNADOES WILL
BE POSSIBLE SATURDAY EVENING. THE MOST LIKELY AREAS TO SEE SEVERE
THUNDERSTORMS WILL BE ALONG AND SOUTH OF THE I-85 CORRIDOR. HEAVY
RAINFALL CAN ALSO BE EXPECTED...ESPECIALLY IN AREAS NEAR THE
SOUTHERN ESCARPMENT OF THE BLUE RIDGE.

WEST AND NORTHWEST WINDS WILL BECOME GUSTY BEHIND THE FRONT ON
SUNDAY. GUSTS AS HIGH AS 40 MPH WILL BE POSSIBLE.

FREEZING TEMPERATURES WILL BE POSSIBLE ACROSS THE PIEDMONT AND
FOOTHILLS MONDAY MORNING.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION WILL NOT BE NEEDED.

LANE