Severe Thunderstorm Warning 526, NWS Greenville-Spartanburg, SC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
233 PM EDT TUE AUG 15 2006

.SHORT TERM /TONIGHT THROUGH WEDNESDAY/...
SCATTERED TO NUMEROUS SHOWERS/TSTMS HAVE FINALLY DEVELOPED ACROSS
EAST TENN AND WESTERN NC ALONG/AHEAD OF WEAK FRONTAL BOUNDARY.
ALTHOUGH RATHER DENSE MID-LEVEL CLOUDINESS EARLIER TODAY HINDERED
HEATING SOMEWHAT...DEWPOINTS IN THE LOWER 70S ARE RESULTING IN A
MODERATELY UNSTABLE AIRMASS ACROSS MUCH OF THE AREA THIS AFTERNOON.
AS THE FRONT SAGS TO THE SOUTHEAST...AND CONVERGENCE ALONG
PRE-FRONTAL TROUGH CONTINUES...ADDITIONAL CONVECTIVE DEVELOPMENT
WILL OCCUR OUTSIDE OF THE MNTNS DURING THE AFTERNOON AND EVENING.
CURRENT THINKING IS TO ALLOW MNTN LIKELY POPS TO EXPIRE AT THE END
OF THE FIRST PERIOD AND CONTINUE TO FEATURE SOLID CHANCES IN ALL
AREAS DURING THE EARLY PART OF THE FIRST PERIOD. THIS IS MORE IN
LINE WITH THE GFS SOLUTION...AS THE NAM IS VERY WET FOR THIS EVENING
IN THE PIEDMONT...HINTING AT ORGANIZED CONVECTION DEVELOPING THIS
EVENING. THIS IS DUE TO VERY STRONG CONVERGENCE DEVELOPING ALONG THE
FRONT/TROUGH AXIS...WHICH RESULTS IN UPPER 70S DEWPOINTS POOLING
ALONG THE BOUNDARY...WHICH RESULTS IN RIDICULOUSLY HIGH CAPE VALUES.
THIS JUST DOESN/T SEEM PLAUSIBLE. SHEAR AND FORCING ARE TOO WEAK FOR
ORGANIZED CONVECTIVE DEVELOPMENT...AND THE NAM HAS HAD A HABIT OF
OVERDOING LOW LEVEL CONVERGENCE/CONVECTIVE PRECIP LATELY. (EVEN IF
THE NAM IS HANDLING THE CONVERGENCE WELL...THE SUGGESTION OF
DEWPOINTS NEAR 80 POOLING ALONG THE BOUNDARY SEEMS A BIT ABSURD.)

THE BOUNDARY WILL MORE OR LESS STALL ACROSS THE SOUTHERN ZONES OR
JUST SOUTH OF THE AREA EARLY WEDNESDAY...BUT MOISTURE WILL ONCE
AGAIN REMAIN PLENTIFUL W/IN EASTERLY FLOW NORTH OF THE BOUNDARY.
THIS COULD LEAD TO DEVELOPMENT OF RATHER WIDESPREAD STRATOCU LATE
TONIGHT AND WED ACROSS THE AREA...LIMITING INSTABILITY AND THEREFORE
CONVECTIVE COVERAGE. WILL FEATURE SOLID CHANCE POPS ACROSS THE
SOUTH...TAPERING TO SLIGHT CHANCES IN DRIER AIR ACROSS THE FAR WEST.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH TUESDAY/...
SHORTWAVE MOVES OFF THE NORTHEAST COAST THURSDAY NIGHT AS SURFACE
FRONT WEAKENS TO OUR SOUTH AND EVENTUALLY DISSIPATES.  UPPER RIDGE
WILL DOMINATE THE WEATHER FROM THE SOUTH CENTRAL PORTION TO ACROSS
THE SOUTHEAST THURSDAY AND FRIDAY.  HOWEVER...A TROPICAL LOW OFF THE
FLORIDA/GEORGIA COAST MAY DEVELOP SLOWLY AS IT IS PROJECTED TO MOVE
TO NEAR THE NORTH CAROLINA COAST TOWARD THE END OF THE WEEK AND
STALL OUT.  MODEL CONFIDENCE IS IN THE GFS AS THE THE NAM STILL HAS
THE TROPICAL LOW GOING TOWARD JACKSONVILLE.

ON WEDNESDAY EVENING...SHOWERS AND A FEW THUNDERSTORMS OVER THE
SOUTHERN PIEDMONT SHOULD BE WINDING DOWN AS SURFACE HIGH PRESSURE
OVER THE MID ATLANTIC BUILDS INTO THE AREA FROM THE NORTHEAST.  SOME
WEAK INSTABILITY...MAINLY TO THE SOUTH NEAR THE DISSIPATING FRONTAL
BOUNDARY MAY TRIGGER A FEW SHOWERS AND THUNDERSTORMS ON THURSDAY
AFTERNOON.  THE SAME STORY HOLDS FOR FRIDAY AFTERNOON...BUT EVEN
LESS POTENTIAL AS THE MID ATLANTIC HIGH RIDGES IN FROM THE
NORTHEAST.  HOWEVER...THE CONCERN WILL BE WHERE WILL THE TROPICAL
LOW BE AT THAT TIME.  HPC PROGS IT TO BE NEAR CAPE HATTERAS ON
FRIDAY AND WE WILL SEE AS STEERING IS WEAK.  THIS LOW MAY EVEN DRIFT
SOUTHWEST TO NEAR MYRTLE BEACH BY SUNDAY MORNING.

THE NEXT SIGNIFICANT SHORTWAVE IS EXPECTED TO CROSS THE GREAT LAKES
ON SATURDAY WITH THE SURFACE COLD FRONT CROSSING THE OHIO RIVER
VALLEY SATURDAY NIGHT AND EARLY SUNDAY.  AS THE FRONT APPROACHES OUR
REGION...CHANCES OF RAIN WILL BE ON THE INCREASE...FIRST IN THE
MOUNTAINS LATE SATURDAY AND SATURDAY NIGHT...THEN THE REST OF THE
AREA SUNDAY AND MONDAY.  THE FRONT COULD MOVE AS FAR SOUTH AS THE
SOUTH CAROLINA MIDLANDS AND NORTH CAROLINA COAST BY MONDAY
MORNING...THEN WOBBLE AROUND THE CAROLINAS DURING EARLY PART OF THE
UPCOMING WEEK.  AT THAT TIME...THE STATUS OF THE TROPICAL LOW AND
ITS LOCATION IS ANYBODYS GUESS.

&&

.AVIATION...
CHALLENGING AVIATION FORECAST THIS PERIOD...AS DOUBTS LINGER WITH
REGARD TO CONVECTIVE COVERAGE THIS AFTERNOON...AND THE POSSIBILITY
OF LOW STRATOCU DEVELOPING IN EASTERLY FLOW LATE TONIGHT AND WED.
CONVECTION SHOULD BE MOST WIDESPREAD ACROSS THE MNTNS...AND TEMPOS
FOR TSRA HAVE BEEN INCLUDED AT KAVL THROUGH 21Z...ALTHOUGH THE
POTENTIAL WILL LINGER INTO THE EVENING HOURS. ELSEWHERE...CONVECTION
HAS BEEN LIMITED TO VCTS IN THE MORE UNSTABLE AIR (KCLT) AND VCSH/CB
ELSEWHERE. AFTER THE FRONT SAGS SOUTH LATER TONIGHT...EASTERLY
UPSLOPE FLOW MAY RESULT IN LOW STRATOCU...ESPECIALLY NEAR THE BLUE
RIDGE. HOWEVER...NONE OF THE GUIDANCE PACKAGES SEEM VERY EXCITED
ABOUT THIS POTENTIAL. FOR NOW...THINK IT IS BEST TO ADVERTISE MVFR
CONDITIONS AT MOST TERMINALS BEGINNING SHORTLY BEFORE SUNRISE AND
CONTINUING THROUGH THE MORNING.

&&

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

SHORT TERM...JDL
LONG TERM...DEO
AVIATION...JDL

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
600 AM EDT TUE AUG 15 2006

GAZ010-017-018-026-028-029-NCZ033-035>037-048>053-056>059-062>065-
068>072-082-501>510-SCZ001>014-019-161000-
RABUN-HABERSHAM-STEPHENS-FRANKLIN-HART-ELBERT-AVERY-ALEXANDER-
IREDELL-DAVIE-MADISON-YANCEY-MITCHELL-SWAIN-HAYWOOD-BUNCOMBE-
CATAWBA-ROWAN-GRAHAM-NORTHERN JACKSON-MACON-SOUTHERN JACKSON-
TRANSYLVANIA-HENDERSON-CLEVELAND-LINCOLN-GASTON-MECKLENBURG-
CABARRUS-UNION NC-CALDWELL MOUNTAINS-GREATER CALDWELL-
BURKE MOUNTAINS-GREATER BURKE-MCDOWELL MOUNTAINS-EASTERN MCDOWELL-
RUTHERFORD MOUNTAINS-GREATER RUTHERFORD-POLK MOUNTAINS-
EASTERN POLK-OCONEE MOUNTAINS-PICKENS MOUNTAINS-
GREENVILLE MOUNTAINS-GREATER OCONEE-GREATER PICKENS-
GREATER GREENVILLE-SPARTANBURG-CHEROKEE-YORK-ANDERSON-ABBEVILLE-
LAURENS-UNION SC-CHESTER-GREENWOOD-
600 AM EDT TUE AUG 15 2006

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
SHOWERS AND THUNDERSTORMS WILL BE QUITE NUMEROUS IN THE NORTH
CAROLINA MOUNTAINS TODAY...WHILE SCATTERED SHOWERS AND
THUNDERSTORMS ARE EXPECTED IN THE FOOTHILLS AND PIEDMONT. A
SECONDARY MAXIMUM OF COVERAGE IS EXPECTED FOR LOCATIONS ALONG AND
EAST OF INTERSTATE 77 LATE THIS AFTERNOON INTO THIS EVENING. A FEW
THUNDERSTORMS COULD BECOME STRONG IN THE PIEDMONT LATE THIS
AFTERNOON...DEPENDING ON HOW WARM SURFACE TEMPERATURES GET LATER TODAY.
SCATTERED SHOWERS AND THUNDERSTORMS THIS EVENING SHOULD BEGIN TO
DIE OUT AFTER MIDNIGHT.

.DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY
NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME. SCATTERED SHOWERS
AND THUNDERSTORMS ARE EXPECTED AGAIN WEDNESDAY AND WEDNESDAY
NIGHT...BUT THE GREATEST COVERAGE THESE PERIODS SHOULD SHIFT TO
UPSTATE SOUTH CAROLINA...NORTHEAST GEORGIA AND THE SOUTHERN TIER
OF MOUNTAINS IN WESTERN NORTH CAROLINA. DRY HIGH PRESSURE BUILDING
IN BEGINNING THURSDAY IS EXPECTED TO RESULT IN A PROLONGED...FAIR
PERIOD WITH TEMPERATURES AT...OR SLIGHTLY ABOVE...NORMAL.

.SPOTTER INFORMATION STATEMENT...
SPOTTER ACTIVATION IS NOT EXPECTED TODAY OR TONIGHT.

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