Severe Thunderstorm Warning 16, NWS Greenville-Spartanburg, SC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
314 AM EST SAT APR 5 2003

COLD FRONT TO OUR WEST QUITE EVIDENT PER UPSTREAM 88-D REFLECTIVITY
LOOPS...WITH A DEVELOPING LINE OF STRONG CONVECTION LINING UP ACROSS
MIDDLE TENNESSEE. THIS LINE...AT ITS PRESENT RATE OF MOVEMENT...WILL
ENTER OUR WESTERN CWFA EARLY THIS MORNING.
FORCING...MEANWHILE...ROTATES TO THE NORTHEAST...LEAVING THE FRONT
TO GO IT ALONE AS IT CROSSES THE REGION.

BOTH GFS AND ETA AGREE SOMEWHAT THAT ANY PRECIPITATION WITH THIS
FRONT WILL BE OUT WELL AHEAD OF THE MAIN FRONT ITSELF. TIME HEIGHTS
DRY OUT DRAMATICALLY THIS AFTERNOON FROM WEST TO EAST FROPA ITSELF
APPEARS TO BE EARLY EVENING BEFORE CLEARING ALL OF THE CWFA. GIVEN
THAT THE FRONT WILL BE ACROSS THE FOOTHILLS AND PIEDMONT AT TIME OF
MAXIMUM HEATING...AND WITH ABUNDANT LOW LEVEL SHEAR PRESENT THROUGH
MID AFTERNOON...WE COULD SEE SOME STRONG CONVECTION THIS AFTERNOON.
MODEL INSTABILITY NOT GREAT...HOWEVER...WITH CAPES NOT QUITE
REACHING 1000 J/KG AND LIFTED INDICES JUST BARELY BELOW ZERO. LOW
WET BULB ZEROS SUGGEST A CHANCE OF HAIL WITH ANY CONVECTION THIS
AFTERNOON.

FRONT PROGD BY MODELS TO STALL TO OUR SOUTH TONITE...THEN SLOWLY
RETURN NORTHWARD AS ANOTHER SURFACE WAVE DEVELOPS ALONG THE GULF
COAST AND TREKS TOWARD THE CENTRAL APPALACHIANS. MOISTURE WITH THE
FRONT GETS SHUNTED TO THE SOUTH...BUT POST FRONTAL UPGLIDE BEGINS
ACROSS THE SAVANNAH RIVER VALLEY AS EARLY AS THE SUNDAY PREDAWN.
STRONG 1041MB HIGH BUILDING SOUTH SIMULTANEOUSLY PROVIDES
INGREDIENTS FOR A CLASSIC COLD AIR DAMMING EVENT. STRONG VORTS
CROSSING THE REGION IN FAST SOUTHWEST FLOW ALOFT SHOULD ENHANCE
PRECIP AMOUNTS AS SURFACE WAVE TREKS NORTHEAST...AND DRAGS FRONT
SLOWLY WITH IT. POSSIBLE THERMAL MOISTURE BOUNDARY TO SET UP SHOP
ACROSS CAROLINA PIEDMONT AND TREK SLOWLY TO THE WEST. WILL INTRODUCE
CHANCE POPS FOR SUNDAY...AND CATEGORICAL SUNDAY NIGHT..WITH THUNDER
CHANCE FOR MOUNTAINS...NORTHEAST GEORGIA...AND ALL OF OUR SOUTHERN
AND SOUTHEAST TIER COUNTIES FOR SUNDAY NITE AND MONDAY. EXPECT
PRECIP TO END FROM SOUTH AND WEST MONDAY AFTERNOON. SHOULD BE RATHER
RAW LATE SUNDAY NITE AND EARLY MONDAY...WITH AGEOSTROPHIC SURFACE
WIND ADJUSTMENTS AND TIGHTENING GRADIENT KEEPING BRISK TO WINDY
CONDITIONS IN PLACE. FOR TEMPERATURES...WENT MUCH BELOW GUIDANCE FOR
MONDAY...WITH 50 TO 55 NORTH (1000/85H THICKNESS DOWN TO 1320M
INTERSTATE 40 CORRIDOR) TO 65 TO 70 MOUNTAINS AND SOUTHERN TIER
ZONES. MOST OF DAMMING REGION SHOULD STAY IN 50S THROUGH MONDAY...IF
NOT SEE TEMPERATURES ACTUALLY DROP THROUGH 40S SUNDAY NITE AND
MONDAY IN THE NORTH.

DAY 1 THROUGH 5 PRECIP FROM NCEP PAINTS A WIDE SWATH OF 2 TO 3 INCH
RAINFALL AMOUNTS ACROSS SOUTHERN HALF OF OUR CWFA. SOME OF THAT...NO
DOUBT...ATTRIBUTED TO SOME OF THE LONGER RANGE MODELS DEVELOPING YET
ANOTHER GULF COASTAL SYSTEM FOR MIDWEEK...KEEPING RAIN OVER OUR
REGION THROUGH THURSDAY (GFS AND CANADIAN FEATURE THIS). OUR GRIDS
AND CORRESPONDING ZONES...HOWEVER...AT THIS TIME FEATURE NO
PRECIPITATION BEYOND MONDAY. WILL TRY TO COORDINATE THIS WITH OTHER
OFFICES BEFORE GOING TO PRESS BUT NEXT SHIFT WILL DEFINITELY WANT TO
CAREFULLY LOOK AT INCLUSION OF MIDWEEK PRECIP.

FCSTID =   44
GSP   77  46  63  48 /  30  20  40  90
AND   78  49  64  49 /  40  20  50  90
CLT   78  45  62  48 /  40  20  40  80
HKY   76  43  61  44 /  40  10  30  80
AVL   72  40  63  45 /  40  10  40  80

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

BURRUS

GAZ010-017-018-026-028-029-NCZ033>037-048>059-062>072-082-SCZ001>014-
019-051300-

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
559 AM EST SAT APR 5 2003

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

.DAY ONE...TODAY

A COLD FRONT WILL CROSS THE REGION TODAY...USHERING IN A LINE OF
SHOWERS AND THUNDERSTORMS. SOME OF THE STORMS COULD BECOME QUITE
STRONG...AND THERE IS AN OUTSIDE CHANCE THAT ONE OR TWO COULD
BRIEFLY REACH SEVERE STATUS. HEAVY RAIN COULD FALL IN THE MOUNTAINS
THIS MORNING.

.DAYS TWO THROUGH SEVEN...

A PROLONGED PERIOD OF LIGHT TO MODERATE RAIN APPEARS TO BE SHAPING
UP FOR THE END OF THE WEEKEND...AND THE START OF THE NEW
WEEK...ESPECIALLY FOR NORTHEAST GEORGIA AND THE UPSTATE OF SOUTH
CAROLINA. SOME LOCATIONS COULD RECEIVE OVER THREE INCHES OF RAIN BY
MIDWEEK...ENOUGH TO GENERATE LARGE RISES ON AREA STREAMS...CREEKS
AND RIVERS.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION MAY BE REQUIRED LATER TODAY...ESPECIALLY IN THE
FOOTHILLS AND PIEDMONT.

SAB

NCZ033-048>053-058-059-062-051130-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
516 AM EST SAT APR 5 2003

...LINE OF STRONG TO SEVERE THUNDERSTORMS APPROACHING WESTERN NORTH
CAROLINA...

AT 510 AM EST...WEATHER RADAR SHOWED A LINE OF STRONG TO SEVERE
THUNDERSTORMS MOVING THROUGH EAST TENNESSEE...TOWARD WESTERN NORTH
CAROLINA.  AT THE CURRENT SPEED...AROUND 40 MPH MOVEMENT TO THE
EAST...THE LINE WILL REACH THE STATE LINE AROUND 6 AM...AND MOVE
THROUGH THE WESTERN MOUNTAIN COUNTIES BETWEEN 6 AND 7 AM.  ONE STORM
NEAR KNOXVILLE HAS BEEN SEVERE...WITH THE MORRISTOWN NATIONAL
WEATHER SERVICE OFFICE RELAYING A REPORT OF QUARTER SIZE HAIL WEST
OF KNOXVILLE.  ALSO...SOME STRONG WIND GUSTS WERE REPORTED.

THE LINE OF STORMS WILL CAUSE HEAVY RAIN SHOWERS...FREQUENT CLOUD TO
GROUND LIGHTNING...WIND GUSTS FROM 40 TO 50 MPH...AND LIKELY SOME
HAIL. IT IS POSSIBLE ISOLATED DAMAGING WIND GUSTS TO 60 MPH OR
HIGHER...AND LARGE HAIL COULD OCCUR WITH THE STRONGEST STORMS.

LISTEN TO WEATHER RADIO...OR YOUR FAVORITE MEDIA SOURCE...FOR LATER
STATEMENTS AND POSSIBLY WARNINGS.

JONES