Severe Thunderstorm Warning 20, NWS Greenville-Spartanburg, SC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
1102 AM EDT SAT APR 26 2003

COMPLEX WEATHER PATTERN OVER THE EASTERN HALF OF THE NATION TODAY.
LATEST SURFACE ANALYSIS SHOWS A SURFACE LOW OVER THE KENTUCKY COAL
FIELDS...WITH AN OCCLUSION EXTENDING SOUTHEAST TOWARD A TRIPLE POINT
LOW OVER THE NORTHWEST PIEDMONT OF NORTH CAROLINA. FROM THE TRIPLE
POINT LOW...A WARM FRONT EXTENDS NORTHEAST THROUGH THE VIRGINIA
TIDEWATER TO ANOTHER WAVE OFF THE MID ATLANTIC COAST. A COLD FRONT
EXTENDS SOUTHWEST FROM THE TRIPLE POINT LOW THROUGH THE FAR WESTERN
UPSTATE AND NORTHEAST GEORGIA...DOWN TO THE GULF COAST.

UPPER AIR ANALYSIS SHOWS THE 850H FRONT STILL WELL WEST OF OUR AREA.
A STRONG MID LEVEL SHORTWAVE WAS ON THE DOORSTEP OF OUR CWFA...WITH
AN ATTENDANT COLD POOL 85H/50H LAPSE RATES AROUND 6.5 DEG C/KM OVER
THE REGION. THERE IS A CIRCULATION AT 70H OVER EASTERN KENTUCKY.
THIS CIRCULATION IS FORECAST TO MOVE OVER THE CWFA THIS AFTERNOON AS
A WEAKENING WAVE.

WITH BOTH A WARM AND COLD FRONT IN THE VICINITY...A TALE OF TWO AIR
MASSES WILL EXIST FOR MUCH OF THE AFTERNOON. DRIER AIR FILTERING IN
FROM THE WEST WITH THE COLD FRONT...AND MUCH MOISTER...AND
POTENTIALLY UNSTABLE AIR...OVER THE EASTERN CORRIDOR. EQUILBRIUM
LEVELS TODAY QUITE LOW...AND WITH THE ATTENDANT COLD POOL...IT WILL
NOT TAKE MUCH LIFT IN ANY CONVECTION THIS AFTERNOON TO GET SOME
SMALL HAIL. WITH MOISTURE CONVERGENCE ALONG THE ELONGATED WARM FRONT
OVER THE EASTERN CORRIDOR...AND WITH FORCING AHEAD OF THE MAIN UPPER
VORT...IT IS THE INTERSTATE 77 CORRIDOR THAT STANDS THE BEST
COVERAGE OF PRECIPITATION THIS AFTERNOON. BEST CHANCES OF
SEVERE...HOWEVER...STILL OFF EAST OF OUR AREA WHERE THE SURFACE
EQUIVALENT POTENTIAL TEMPERATURE GRADIENT IS THE BEST.

SATELLITE SHOWING OVERCAST SKIES FOR MOST OF THE FORECAST AREA AT
PRESENT...ALTHOUGH SKIES HAVE ALMOST COMPLETELY CLEARED IN EXTREME
NORTHEAST GEORGIA AND THE SAVANNAH RIVER LOCATIONS IN SOUTH
CAROLINA. ONCE THE 850 FRONT HAS CLEARED THE WEST...DOWNSLOPE SHOULD
AID IN CLEARING SKIES FOR GOOD THERE. HOWEVER...WILL MAINTAIN MOSTLY
CLOUDY SKIES FOR MOST ZONES. SATELLITE ALSO SHOWING A RATHER
EXTENSIVE MID LEVEL CLOUD DECK UPSTREAM THAT MIGHT ROTATE AROUND
EVEN INTO NORTHEAST GEORGIA LATER THIS AFTERNOON...SO AM HESITANT TO
GO JUST PARTLY CLOUDY THERE.

UPDATE CHANGES WILL FEATURE OPENING UP THE RANGE OF TEMPERATURES
ACROSS THE NORTHERN MOUNTAINS...WHERE CURRENT READINGS ALREADY NEAR
FORECAST MAXES. LOWERED MAXES A BIT IN THE EASTERN ZONES WITH CLOUD
COVER AND RESIDUAL CONVECTION KEEPING TEMPERATURES DOWN. DID LOWER
POPS TO CHANCE...WITH 50S FOR THE EASTERN CORRIDOR...TAPERING TO
ISOLATED FOR THE FAR WESTERN NORTH CAROLINA MOUNTAINS...EXTREME
NORTHEAST GEORGIA AND THE IMMEDIATELY FOOTHILL AND PIEDMONT AREAS OF
UPSTATE SOUTH CAROLINA.

FCSTID =   44
GSP   73  52  77  53 /  50  10   0   0
AND   74  52  78  53 /  30  10   0   0
CLT   73  52  77  53 /  60  10   0   0
HKY   71  50  75  52 /  60  10   0   0
AVL   66  46  73  47 /  40  10   0   0

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

BURRUS

GAZ010-017-018-026-028-029-NCZ033>037-048>059-062>072-082-SCZ001>014-
019-261200-

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
558 AM EDT SAT APR 26 2003

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

.DAY ONE...TODAY

A FEW SEVERE THUNDERSTORMS WILL BE POSSIBLE TODAY...MAINLY OVER THE
NORTH CAROLINA FOOTHILLS AND PIEDMONT. THE SEVERE WEATHER THREAT
SHOULD END BY MID AFTERNOON AS THUNDERSTORMS MOVE EAST OF THE AREA.
SEE OUR PRODUCT (CAESPSGSP) FOR ADDITIONAL INFORMATION.

.DAYS TWO THROUGH SEVEN...

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION MAY BE REQUIRED THIS MORNING AND EARLY THIS
AFTERNOON.

MCAVOY

NCZ034>037-054>057-066>072-082-SCZ003-006>009-012>014-262000-

SEVERE WEATHER OUTLOOK
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
1110 AM EDT SAT APR 26 2003

...STILL A CHANCE OF SEVERE WEATHER IN PARTS OF THE PIEDMONT...

WITH THE COMBINATION OF MID DAY HEATING...AND WITH THE INFLUENCE OF
COLD AIR ALOFT...THERE WILL STILL BE A RISK OF STRONG TO SEVERE
THUNDERSTORMS UNTIL MID AFTERNOON.  THE BEST CHANCE OF STRONG TO
SEVERE STORMS WILL BE EAST OF A LINE FROM HICKORY NORTH
CAROLINA...TO CHESTER SOUTH CAROLINA.  THE MAIN THREAT FROM THESE
ISOLATED TO SCATTERED STORMS WILL BE HAIL.  STRONG AND GUSTY WINDS
ARE ALSO POSSIBLE.

MOST ANY STORM WHICH DEVELOPS...BECAUSE OF THE COLD AIR ALOFT...WILL
BE CAPABLE OF PEA TO MOTHBALL SIZE HAIL.  A FEW STORMS COULD PRODUCE
LARGE HAIL...ABOUT THE SIZE OF PENNIES OR A BIT LARGER.

FARTHER WEST...ISOLATED TO SCATTERED SHOWERS AND STORMS ARE
EXPECTED...WITH A THREAT OF SMALL HAIL.

JONES

SCZ009-261700-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
1205 PM EDT SAT APR 26 2003

...STRONG THUNDERSTORM TO AFFECT YORK COUNTY THROUGH 1 PM...

AT 1205 PM...NATIONAL WEATHER SERVICE RADAR INDICATED A STRONG
THUNDERSTORM JUST WEST OF SMYRNA MOVING EAST AT 25 MPH. THIS
THUNDERSTORM HAS A HISTORY OF PRODUCING SMALL HAIL AND FREQUENT
LIGHTNING. HALF-INCH HAIL...WIND GUSTS TO 40 MPH...AND BRIEF
TORRENTIAL DOWNPOURS WILL AFFECT THE AREA FROM HICKORY GROVE TO YORK
TO NEAR ROCK HILL THROUGH 1 PM.

THE NATIONAL WEATHER SERVICE WILL CONTINUE TO MONITOR THE PROGRESS
OF THIS THUNDERSTORM IN CASE A WARNING BECOMES NECESSARY.

HG