Severe Thunderstorm Warning 100, NWS Greenville-Spartanburg, SC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
327 PM EDT THU JUN 24 2004

.SHORT TERM...
CURRENT REGIONAL RADAR IMAGERY INDICATES WIDELY SCATTERED CONVECTION
BEGINNING TO DEVELOP IN THE MODERATELY UNSTABLE AIRMASS ACROSS THE
UPSTATE/NORTHEAST GA/AND THE SOUTHERN NC MNTNS. MEANWHILE...FAIRLY
WIDESPREAD CONVECTION CONTINUES TO PUSH NORTHEAST ACROSS PORTIONS OF
EASTERN AL AND WESTERN GA. CURRENT RADAR TRENDS WOULD PLACE THIS
PRECIP INTO OUR WESTERN ZONES WITHIN THE NEXT 2 TO 4 HOURS.
HOWEVER...IT WILL ENCOUNTER A MORE STABLE AIRMASS AS IT MOVES ACROSS
EASTERN GA...AND THERE IS ACTUALLY A DOWNWARD TREND IN UPSTREAM
RADAR ECHOES. NEVERTHELESS...WILL CARRY AT LEAST A SOLID CHANCE POP
ACROSS THE SAVANNAH RIVER VALLEY INTO THE SOUTHWEST MNTNS FOR THIS
EVENING. ELSEWHERE...WILL RETAIN A CHANCE POP...AS WEAKENING FRONTAL
BOUNDARY COULD PROVIDE FOCUS FOR SCATTERED CONVECTION INTO THE
EVENING.

POTENT SW TROUGH ACROSS THE GREAT LAKES REGION WILL CONTINUE DIGGING
SOUTHEAST TONIGHT...SENDING YET ANOTHER FRONTAL BOUNDARY INTO THE
TENN AND OH VALLEYS LATE TONIGHT. A SURFACE WAVE IS EXPECTED TO
DEVELOP ALONG THIS FRONT ACROSS THE MISS VALLEY...IN RESPONSE TO A
WEAK UPPER VORT OVER EAST TX. NOT SURPISINGLY...THE GFS IS MUCH
STRONGER AND FASTER THAN THE ETA (OR ANY OTHER MODEL FOR THAT
MATTER...DUE TO GRID-SCALE CONVECTIVE FEEDBACK) IN MOVING THIS WAVE
NORTHEAST ALONG THE FRONT. HOWEVER... EVEN THE ETA SPREADS A DECENT
AMOUNT OF MOISTURE/UPGLIDE/PRECIP ACROSS THE AREA LATE TONIGHT...ESP
THE MNTNS...AND GUIDANCE PACKAGES FROM BOTH MODELS ARE IN AGREEMENT
THAT CAT POPS ARE WARRANTED LATE TONIGHT ACROSS THE SOUTHWEST MNTNS.
TENN. POPS WILL BE TAPERED TO LIKELY ACROSS THE REMAINDER OF THE
MNTNS...WITH JUST A TOKEN CHANCE ACROSS THE FOOTHILLS AND PIEDMONT.

TOMORROW...THE FRONT IS EXPECTED TO STALL ACROSS THE GREAT TENN
VALLEY DURING THE DAY...WITH CAT POPS EXPANDED TO INCLUDE ALL OF THE
THE TENN BORDER COUNTIES. FLOODING IS A POTENTIAL CONCERN FOR
TOMORROW...ESP ACROSS THE MNTNS...BUT THE MAIN AXIS OF HEAVY
RAINFALL IS EXPECTED TO RESIDE WITH THE FRONT TO OUR WEST. EAST OF
THE MNTNS...COVERAGE OF CONVECTION IS A BIT MORE UNCERTAIN...AS THE
GFS AND ETA DIFFER TREMENDOUSLY IN THEIR MOISTURE FIELDS. THE ETA
DEVELOPS A LEE/PRE-FRONTAL TROUGH ACROSS THE PIEDMONT TOMORROW
AFTERNOON...AND ACTUALLY DRIES THE ATMOSPHERE OUT EAST OF THE
MNTNS...KEEPING THE DEEPER MOISTURE NEARER THE FRONT. MEANWHILE...
THE GFS IS VERY MOIST ACROSS THE ENTIRE AREA. HOWEVER...THIS APPEARS
TO BE DUE TO THE GFS OVERDONE UPGLIDE WHICH DEVELOPS IN RESPONSE TO
ITS OVERDONE SURFACE WAVE. WILL SHY AWAY FROM THE GFS WIDESPREAD
CATEGORICAL POPS...BUT STILL CARRY SOLID CHANCE TO LIKELIES IN THE
PIEDMONT AND FOOTHILLS TOMORROW AFTERNOON. THE FRONT IS EXPECTED TO
MAKE ITS PUSH INTO THE CWFA FRIDAY NIGHT...BEFORE GETTING HUNG UP
ACROSS THE AREA SATURDAY. WILL CONTINUE TO CARRY A TOKEN LOW CHANCE
POP SATURDAY AFTERNOON...BUT CONFINE THEM TO THE SOUTHERN 2/3 OF THE
AREA FOR SUNDAY...AS THE FRONT PUSHES A LITTLE FURTHER SOUTH.

.LONG TERM...
LATEST GFS SHOWS SURFACE WAVE MOVING ACROSS THE CAROLINAS EARLY
MONDAY. IN THE PATTERN DEPICTED BY THE GFS...TIMING OF SUCH FEATURES
REMAINS UNCERTAIN. WILL RESIST RAISING POP SUBSTANTIALLY UNTIL THIS
EVENT DRAWS NEAR...AND WILL THEREFORE KEEP THE CHANCE POP OVERNIGHT
SUNDAY NIGHT AND INTO MONDAY. THE CONSENSUS IS TO MOVE THE SURFACE
BOUNDARY TO THE SOUTH ACROSS SC/GA TUESDAY WITH THE MOISTURE
GRADIENT REMAINING ACROSS THE WESTERN CAROLINAS. ALTHO HIGH PRESSURE
SHOULD BUILD IN FROM THE WEST...WILL KEEP THE CHANCE POP FOR THIS
PACKAGE SINCE DEEPER MOISTURE IS AVAILABLE. ON WEDNESDAY...
HOWEVER...WILL DROP PRECIP MENTION OUTSIDE THE MOUNTAINS AS NEWEST
GUIDANCE MOVES THE BOUNDARY EVEN FARTHER TO THE SOUTH AS HIGH MOVES
PAST. TEMPS WILL BE RAISED ABOUT A CATEGORY WEDNESDAY WITH THE
MAINLY DRY FORECAST...OTHERWISE FEW TEMP CHANGES. MOISTURE MAY BEGIN
RETURNING THURSDAY...SO A CHANCE POP WILL BE INCLUDED. &&

.AVIATION...
LOW CLOUD MVFR CEILINGS REMAINING ACROSS FORECAST AREA SHOULD BE
SHORT LIVED...AND BY 19Z...WARMING BOUNDARY LAYER SHOULD BRING THEM
INTO VFR CATEGORY. WATCHING CONVECTION ON KFFC RADAR MOVING INTO WRN
GA AT 17Z WHILE ATMOSPHERE BEGINS TO DESTABILIZE ACROSS THE WRN
CAROLINAS IN WAKE OF EARLY MORNING PRECIP ACTIVITY. EXPECT SCATTERED
THUNDERSTORMS TO MOVE IN ACROSS THE REGION DURING THE LATE AFTERNOON.
AS WITH LAST FEW DAYS...CONVECTIVE DEBRIS WILL LINGER ACROSS THE
AREA IN THE EVENING. AFTER 04Z OR SO...ANOTHER DIFFICULT CALL ON
CIG/VISBY AS MODEL GUIDANCE HAS NOT DONE PARTICULARLY WELL OF LATE.
WITH OLD FRONTAL BOUNDARY EXPECTED TO REMAIN IN AREA AS IT WASHES
OUT...THINK WE WILL SEE AT LEAST MVFR CLOUDS AGAIN IN THE EARLY
MORNING HOURS. EXPECT THIS TO PERSIST INTO THE MIDDLE PART OF
FRIDAY...UNTIL CEILINGS LIFT AGAIN WITH WARMING.

&&

.PRELIMINARY POINT TEMPS/POPS...
GSP  70  83  69  85 /  40  60  50  30
AND  69  84  69  85 /  40  60  50  30
CLT  69  85  69  85 /  30  50  40  40
HKY  69  83  67  84 /  40  60  40  30
AVL  66  78  64  80 /  60  70  50  30
&&

.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&

LANE/MOORE

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
531 AM EDT THU JUN 24 2004

GAZ010-017-018-026-028-029-NCZ033>037-048>059-062>072-082-SCZ001>014-
019-250930-
ABBEVILLE SC-ALEXANDER NC-ANDERSON SC-AVERY NC-BUNCOMBE NC-BURKE NC-
CABARRUS NC-CALDWELL NC-CATAWBA NC-CHEROKEE SC-CHESTER SC-
CLEVELAND NC-DAVIE NC-ELBERT GA-FRANKLIN GA-GASTON NC-GRAHAM NC-
GREATER GREENVILLE SC-GREATER OCONEE SC-GREATER PICKENS SC-
GREENVILLE MOUNTAINS SC-GREENWOOD SC-HABERSHAM GA-HART GA-HAYWOOD NC-
HENDERSON NC-IREDELL NC-LAURENS SC-LINCOLN NC-MACON NC-MADISON NC-
MCDOWELL NC-MECKLENBURG NC-MITCHELL NC-NORTHERN JACKSON NC-
OCONEE MOUNTAINS SC-PICKENS MOUNTAINS SC-POLK NC-RABUN GA-ROWAN NC-
RUTHERFORD NC-SOUTHERN JACKSON NC-SPARTANBURG SC-STEPHENS GA-
SWAIN NC-TRANSYLVANIA NC-UNION SC-UNION NC-YANCEY NC-YORK SC-
531 AM EDT THU JUN 24 2004

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

.DAY ONE...

SCATTERED THUNDERSTORMS ARE EXPECTED TODAY AND TONIGHT...BECOMING
MORE NUMEROUS FROM ASHEVILLE TO THE GREAT SMOKY MOUNTAINS LATE
TONIGHT.

.DAYS TWO THROUGH SEVEN...

NUMEROUS THUNDERSTORMS ARE EXPECTED FRIDAY. SCATTERED THUNDERSTORMS
ARE EXPECTED SATURDAY THROUGH WEDNESDAY.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION IS NOT ANTICIPATED.

07