Severe Thunderstorm Warning 471, NWS Greenville-Spartanburg, SC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
251 PM EDT TUE JUL 25 2006

.SHORT TERM /TONIGHT THROUGH FRIDAY/...
A WEAK SHORTWAVE TROUGH WILL CONTINUE OFF THE ATLANTIC COAST
TONIGHT. THE NORTHERN END OF A WEAK MID LEVEL RIDGE WILL SHORTLY
AMPLIFY OVER THE FORECAST AREA...DRYING OUT THE MID AND UPPER
LEVELS. A LARGE MID LEVEL RIDGE REMAINS PARKED OVER THE GREAT
BASIN...THOUGH IT HAS DEAMPLIFIED AS THE FLOW ACROSS THE
CONTINENTAL U.S. HAS BECOME MORE ZONAL. A WEAK SURFACE BOUNDARY
WILL PROGRESS EASTWARD THROUGH THE FORECAST AREA THIS
EVENING...MOVING OFF THE CAROLINA COAST TONIGHT.

CUMULUS FIELDS WILL DISSIPATE THIS EVENING...AS WELL AS DIURNAL
CONVECTION. EASTWARD MOVING SURFACE BOUNDARY WILL HELP TO INITIATE
CONVECTION THROUGHOUT THE EVENING HOURS...EVEN AFTER SUNSET. AREAS
OF FOG ARE EXPECTED TO DEVELOP THROUGHOUT MOST OF THE FORECAST AREA
OVERNIGHT. SOME LINGERING HAZE IN THE LOWER PIEDMONT MAY PERSIST
THROUGH WED. LOW VISIBILITIES SHOULD BE MIXED OUT EARLIER THAN
TRENDS OVER THE PAST COUPLE OF DAYS. DRY AIR ENTRAINING INTO THE MID
AND UPPER LEVELS THROUGH WED. HIGH AND MID LEVEL CLOUDS ARE NOT
EXPECTED TO BE AS WIDESPREAD AS ON TUES. LOW LEVELS SHOULD REMAIN
FAIRLY MOIST...LOWER 70S...UPPER 60S THROUGHOUT THE PIEDMONT AND
FOOTHILLS. CHANCE POPS WILL RETURN TO THE MTNS WED...WITH DRIER
CONDITIONS FOR THE REST OF THE FORECAST AREA.

NAM AND GFS SHOW BERMUDA RIDGING RETURNING OVER THE CWFA THURSDAY
AND FRIDAY. NAM HAS THE AXIS OF THE RIDGE ALMOST ON TOP OF THE
CWFA THURSDAY THEN SHOWS SOME WEAKENING FRIDAY. THE GFS KEEPS THE
AXIS FARTHER SOUTH. AS A RESULT...NAM CAPS THE ATMOSPHERE THURSDAY
THEN ERODES THE CAP FOR FRIDAY. GFS KEEPS THE ATMOSPHERE UNSTABLE
EACH DAY. ALTHOUGH WEAK ON THE NAM...BOTH MODELS SHOW LOW LEVEL
CONVERGENCE EACH AFTERNOON. THEREFORE HAVE TONED DOWN THE POP
OUTSIDE OF THE MOUNTAINS FOR THURSDAY TO ACCOUNT FOR THE
UNCERTAINTY...BUT KEPT CHANCE ALL AREAS. CHANCE DIURNAL POP AGAIN
FOR FRIDAY. NEAR NORMAL TEMPS CONTINUE EACH DAY.

&&

.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
OPERATIONAL GFS FAIRLY CLOSE TO ENSEMBLES AND OTHER MODELS UNTIL THE
END OF THE PERIOD. GFS INITIALLY DROPS SURFACE FRONT TOO FAR SOUTH
THEN PREVIOUS RUNS DEVELOPED STRONG RIDGING OVER THE EAST COAST.
12Z GFS HAS WEAKENED THE RIDGING...BUT HAS ANOMALOUSLY STRONG
SHORTWAVES AND SURFACE LOWS OVER THE CWFA. HAVE FOLLOWED CONSENSUS
FORECAST WHICH LEAVES THE FRONT TO OUR NORTH...BUT DOES DEVELOP
DECENT LEE TROUGH OVER THE AREA. CONSENSUS IS ALSO AGAINST THE
UPPER AND SURFACE LOWS. THEREFORE WARM...MOIST UNSTABLE AIR MASS
REMAINS ACROSS THE AREA. MAINLY DIURNAL CONVECTION EXPECTED WITH
CHC ALL AREAS EARLY... THEN CHC MOUNTAINS/SLIGHT CHC ELSEWHERE IN
THE MIDDLE...AND CHC ALL AREAS BY THE END. NEAR TO JUST ABOVE
NORMAL TEMPS WILL CONTINUE THROUGH THE PERIOD.

&&

.AVIATION...
NIL AMD KAVL TAF UNTIL COMMUNICATION PROBLEM WITH THE ASOS IS CORRECTED.

LIMITED CONVECTION EXPECTED OVER THE NC MTNS THIS AFTERNOON...MOVING
INTO THE PIEDMONT LATER IN THE EVENING. I FAVORED MAV GUIDANCE FOR
VSBYS IN PLACES THAT HAVE HISTORICALLY KEPT FOG THROUGH MOST OF THE
MORNING. MID AND LOWER LEVEL DRYING WILL BEGIN TO OCCUR OVERNIGHT.
MOSTLY CLEAR CONDITIONS WILL FILTER THROUGH THE FRENCH BROAD
VALLEY...ALONG WITH SOME CLEARING OF THE CENTRAL PIEDMONT. FOG
TIMING MAY BECOME AN ISSUE IN THE MOUNTAINS FOR MOST OF THE NIGHT
AND DEVELOP EARLIER THAN PIEDMONT TAF SITES. CLEARING
SKIES...PERSISTENT LOW LEVEL MOISTURE...AND LIGHT WINDS WILL RESULT
AREAS OF FOG OVER THE FORECAST AREA. VFR CONDITIONS WILL RETURN
EARLIER IN THE MORNING WED THAN OBSERVED ON TUES MORNING...WITH
DRIER BOUNDARY LAYER AND BETTER MIXING.

&&

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

SHORT TERM...GMS/JAT/RWH
LONG TERM...RWH
AVIATION...GMS/JAT

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
615 AM EDT TUE JUL 25 2006

GAZ010-017-018-026-028-029-NCZ033-035>037-048>053-056>059-062>065-
068>072-082-501>510-SCZ001>014-019-261015-
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-
615 AM EDT TUE JUL 25 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

SCATTERED THUNDERSTORMS ARE EXPECTED ACROSS THE REGION AGAIN THIS
AFTERNOON AND EVENING. A FEW OF THE STRONGER THUNDERSTORMS COULD
PRODUCE ENOUGH RAIN OVER A SHORT ENOUGH TIME TO CAUSE MINOR
FLOODING OF POOR DRAINAGE AREAS.

.DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY

SCATTERED MAINLY AFTERNOON AND EVENING THUNDERSTORMS ARE EXPECTED
TO DEVELOP EACH DAY.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION WILL NOT BE NEEDED.

MOORE

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
535 PM EDT TUE JUL 25 2006

GAZ026-028-SCZ004-010-252230-
ANDERSON-FRANKLIN-GREATER OCONEE-HART-
535 PM EDT TUE JUL 25 2006

...A STRONG THUNDERSTORM WAS AFFECTING ANDERSON...FRANKLIN...HART AND
OCONEE COUNTIES...

AT 529 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
STRONG THUNDERSTORM 7 MILES SOUTHWEST OF SANDY SPRINGS...OR 10 MILES
WEST OF ANDERSON. THIS STORM WAS MOVING SLOWLY TOWARD THE SOUTHEAST.

WINDS 30 TO 40 MPH ARE EXPECTED WITH THIS STORM.

THIS STORM WILL MOVE OVER THE SOUTHERN HALF OF LAKE HARTWELL OVER
THE NEXT HOUR.  BOATERS ARE URGED TO GET OFF THE LAKE AS THIS STORM
MOVES OVERHEAD.  FREQUENT LIGHTNING AND GUSTY WINDS ARE A PARTICULAR
THREAT TO BOATS ON THE LAKE.

INTENSE LIGHTNING IS OCCURRING WITH THIS STORM. IF OUTDOORS...STAY
AWAY FROM ISOLATED HIGH OBJECTS SUCH AS TREES. MOVE INDOORS IF
POSSIBLE. WHEN INDOORS...STAY AWAY FROM WINDOWS AND DOORS AND AVOID
USING TELEPHONES UNLESS IT IS AN EMERGENCY. TRY TO UNPLUG UNNECESSARY
ELECTRICAL APPLIANCES BEFORE THE THUNDERSTORM APPROACHES.

DICARLO