Severe Thunderstorm Warning 2, NWS Greenville-Spartanburg, SC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
342 AM EST SAT FEB 22 2003

PRECIP HAS BEEN VERY SLOW IN DEVELOPING OVERNIGHT ACROSS THE WESTERN
CAROLINAS...AS WIDESPREAD CONVECTION UPSTREAM HAS MANAGED TO HINDER
DEEP MOISTURE TRANSPORT INTO THE REGION. HOWEVER...STRENGTHENING
UPGLIDE HAS FINALLY RESULTED IN AN AREA OF RAIN...WITH EMBEDDED
CONVECTION...BLOSSOMING OVER THE UPSTATE AND INTO SOUTHERN NC.
SQUALL LINE APPEARS TO BE ORGANIZING OVER EASTERN ALABAMA AT THIS
TIME...AND EXPECT THIS FEATURE TO MOVE RAPIDLY NORTHEAST TOWARD OUR
CWFA THROUGH THE REMAINDER OF THE MORNING...AS POTENT SW TROUGH
LIFTS OUT OF THE LOWER MISS VALLEY. SEVERE THREAT WILL DEPEND
LARGELY ON HOW FAR NORTH THE WEDGE BOUNDARY LIFTS DURING THE DAY.
SURFACE PRESSURE AND LI PROGS FROM THE MESOETA HINT AT SOME RIDGING
HANGING ON ALONG THE I-40 CORRIDOR AT LEAST THROUGH LATE MORNING.
HAVE OPTED TO ALLOW THE ENTIRE CWA TO BECOME WARM SECTORIZED BY THIS
AFTERNOON...BUT WILL HAVE A WIDE RANGE OF TEMPS...FROM THE UPPER 50S
ACROSS THE NORTHWEST NC PIEDMONT...TO LOWER 70S ACROSS THE SOUTH
PART OF THE UPSTATE.

STILL ANTICIPATE SQUALL LINE MAKING ITS WAY THROUGH THE WESTERN HALF
OF THE CWA BY LATE MORNING...AND THROUGH THE EASTERN HALF BY EARLY
AFTERNOON. INSTABILITY WILL BE MARGINAL AT BEST DURING THIS
TIMEFRAME...AND PRIMARY SEVERE THREAT WILL BE FROM CONVECTIVE
ELEMENTS MIXING DOWN THE 50-60 KT WINDS THAT WILL BE IN PLACE ABOVE
THE BOUNDARY LAYER. BASED ON THIS...WE ARE LEANING TOWARD ISSUANCE
OF A HIGH WIND WARNING IN THE MOUNTAINS...BUT WILL TAKE ANOTHER 30
MINUTES TO MULL THAT OVER. ONE OF THE BIG QUESTIONS THEN BECOMES
WHETHER OR NOT AREAS WEST OF THE MCS WILL DESTABILIZE THIS
AFTERNOON. AS THE SW TROUGH LIFTS NORTHEAST OF THE AREA...MUCH DRIER
MID/UPPER LEVEL AIR WILL ADVECT OVER THE REGION. WITH LAPSE RATES
APPROACHING 7C/KM AND SURFACE HEATING...THE ETA DEPICTS A QUITE
UNSTABLE AIRMASS DEVELOPING THIS AFTERNOON...ESP OVER THE UPSTATE.
THIS CREATES SOME CONCERN THAT SCATTERED DEEP CONVECTION COULD
DEVELOP AHEAD OF THE SURFACE FRONT DURING THE AFTERNOON. AS FAR AS
QPF...MODEL CONSENSUS IS TO MAINTAIN HIGHEST QPF WEST OF THE
SOUTHERN APPALACHIANS...CLOSER TO THE TRACK OF THE SURFACE LOW. WILL
CONTINUE TO ADDRESS THR THREAT FOR ISOLATED CONVECTIVE-RELATED HEAVY
RAINFALL AMOUNTS IN AN SPS.

THE FRONT IS ECPECTED TO SWEEP RAPIDLY ACROSS THE AREA OVERNIGHT...
AND SHOULD BE EAST OF THE CWFA BY 12Z. WINDS WILL REMAIN QUITE
STRONG BEHIND THE FRONT THROUGH SUNDAY MORNING...BEFORE PRESSURES
BEGIN FALLING IN ADVANCE OF ANOTHER SYSTEM THAT WILL MOVE WEST OF
THE APPALACHIANS SUNDAY NIGHT. MOISTURE CONTINUES TO LOOK RATHER
SPARSE WITH THIS FEATURE...AND POPS WILL BE ADVERTISED ONLY ALONG
THE TENNESSEE LINE.

NO SIGNIFICANT CHANGES WILL BE MADE TO THE FORECAST PAST SUNDAY
NIGHT.

FCSTID = 4
GSP   66  42  58  37 /  90  40   0  20
AND   66  42  58  37 /  90  40   0  20
CLT   66  42  57  36 /  90  40   0  20
HKY   59  39  52  34 /  90  40  10  20
AVL   62  38  49  32 /  90  40  10  20

.GSP...
GA...NONE.
NC...NONE.
SC...NONE.

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GAZ010-017-018-026-028-029-NCZ033>037-048>059-062>072-082-SCZ001>014-
019-221300-

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
619 AM EST SAT FEB 22 2003

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

.DAY ONE...WIDESPREAD SHOWERS AND THUNDERSTORMS WILL AFFECT THE
WESTERN CAROLINAS AND NORTHEAST GEORGIA. SOME OF THE STORMS WILL
LIKELY BE SEVERE...ESPECIALLY LATE THIS MORNING INTO THIS AFTERNOON.
HEAVY RAINFALL COULD ALSO PRODUCE ISOLATED FLASH FLOODING. WINDS
WILL REMAIN STRONG AFTER THE PRECIPIATION ENDS TONIGHT...ESPECIALLY
ACROSS THE MOUNTAINS. FOR MORE INFORMATION...SEE CAESPSGSP.

.DAYS TWO THROUGH SEVEN...

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION WILL LIKELY BE NEEDED BY EARLY AFTERNOON...
ESPECIALLY ALONG THE I-85 CORRIDOR.

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GAZ010-017-018-026-028-029-NCZ033>037-048>059-062>072-082-SCZ001>014-
019-222100-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
502 AM EST SAT FEB 22 2003

...SEVERE WEATHER AND HEAVY RAINFALL EXPECTED ACROSS THE AREA
TODAY...

AN AREA OF LOW PRESSURE WILL MOVE ACROSS THE TENNESSEE VALLEY
THROUGHOUT THE DAY. THIS WILL ALLOW A WARM FRONT TO LIFT NORTHWARD
ACROSS THE WESTERN CAROLINAS AND NORTHEAST GEORGIA THIS MORNING
THROUGH THE EARLY AFTERNOON. WARM...MOIST...AND UNSTABLE AIR WILL
MOVE IN BEHIND THE WARM FRONT...AND CREATE A FAVORABLE ENVIRONMENT
FOR THE DEVELOPMENT OF THUNDERSTORMS. A LARGE AREA OF RAIN WITH
EMBEDDED THUNDERSTORMS WILL MOVE ACROSS THE AREA THIS MORNING...AND
INTO THE EARLY AFTERNOON. A FEW OF THESE STORMS WILL LIKELY BECOME
SEVERE...WITH THE MAIN THREAT BEING IN THE FORM OF DAMAGING STRAIGHT
LINE WINDS. ISOLATED WEAK TORNADOES WILL ALSO BE POSSIBLE...
ESPECIALLY ALONG THE NORTHWARD MOVING WARM FRONT.

AS A COLD FRONT MOVES TOWARD THE AREA LATER THIS AFTERNOON INTO THIS
EVENING...ANOTHER ROUND OF THUNDERSTORMS WILL BE POSSIBLE. THESE
STORMS COULD ALSO BE SEVERE...WITH A CONTINUED THREAT OF DAMAGING
WINDS. HOWEVER...IT IS POSSIBLE THAT THE ATMOSPHERE WILL BECOME MORE
UNSTABLE THIS AFTERNOON...WHICH WOULD ALLOW FOR THE DEVELOPMENT OF
STRONGER STORMS PRODUCING LARGE HAIL AND ISOLATED TORNADOES.

ALTHOUGH SEVERE WEATHER WILL BE POSSIBLE ACROSS THE ENTIRE AREA
TODAY...IT APPEARS THAT THE GREATEST THREAT FOR SEVERE THUNDERSTORMS
WILL BE IN AREAS SOUTH OF I-85. ALTHOUGH THUNDERSTORMS ARE NOT
EXPECTED TO BE AS INTENSE OVER THE MOUNTAINS...WINDS ALOFT TODAY
ARE EXPECTED TO BE VERY STRONG...AND EVEN WEAK STORMS MAY BE CAPABLE
OF BRINGING SOME OF THESE STRONG WINDS INTO THE VALLEYS...RESULTING
IN DAMAGE TO TREES AND POWER LINES.

IN ADDITION TO SEVERE WEATHER...HEAVY RAINFALL WILL ACCOMPANY SOME
OF THE THUNDERSTORMS. THIS COULD PRODUCE ISOLATED FLOODING ALONG
SMALL CREEKS AND STREAMS...AS WELL AS IN URBAN AND POOR DRAINAGE
AREAS.

STAY TUNED TO NOAA WEATHER RADIO OR THE MEDIA FOR THE LATEST
INFORMATION ON THIS SEVERE WEATHER SITUATION...INCLUDING POSSIBLE
WATCHES AND WARNINGS.

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