Flash Flood in North Carolina, September 1 to 2, 2004

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
315 PM EDT WED SEP 1 2004

.SHORT TERM (TONIGHT THROUGH FRIDAY NIGHT)...
KGSP 88-D SHOWS CONVECTION AFFECTING ALL QUADRANTS OF THE CWFA
AT PRESENT...EXCEPT FOR EXTREME NORTHEAST. ISENTROPIC UPGLIDE PER
305K THETA SURFACE...WEAK DIFFERENTIAL POSITIVE VORTICITY ADVECTION
WITH VORTICITY LOBE LIFTING SOUTH TO NORTH...AND GENERAL SLOW
MOVEMENT OF ANY CELLS WILL CALL FOR LIKELY POPS IN THE FAR WEST AND
SOUTHWEST CWFA THIS EVENING. WE WILL INCLUDE A GOOD CHANCE GROUP
FOR THE CENTRAL MOUNTAINS AND CENTRAL UPSTATE...WITH LOW CHANCE FAR
NORTHEAST THIS EVENING. WILL HAVE TO MONITOR FOR HEAVY RAINFALL IN
WEAK STEERING FLOW ENVIRONMENT. WE EXPECT MOST CONVECTION TO END BY
THE START OF THE PREDAWN HOURS...BUT MAINTAINED CHANCE POPS THROUGH
THE OVERNIGHT FOR THE FAR WEST/SOUTHWEST TIER...SINCE WEAK UPPER
DIVERGENCE IS NOTED ON ETA/GFS THROUGH THE PERIOD. MEANWHILE...
DRIER AIR SLOWLY BEGINNING TO INVADE THE EASTERN AND NORTHERN CWFA
LATE. LOW LEVELS STAY MOIST MOUNTAINS/FOOTHILLS...WHERE DENSE FOG
WAS NOTED THIS MORNING SO WE WILL INCLUDE PATCHY DENSE FOG THERE
AGAIN TONITE. OVERNIGHT MINIMUMS WERE RAISED A DEGREE OR TWO OVER
GUIDANCE AS WE HAVE BEEN UNDERFORECASTING LOWS OF LATE.

FOR THURSDAY...SURFACE RIDGE CENTER PROGD OVER SOUTHERN ONTARIO
LATE IS EXPECTED TO SHIFT EAST...CONTINUING ADVECTION OF DRIR AIR
INTO THE REGION. SOUTHWEST CWFA WILL BE THE LAST TO DRY OUT...AND
THERE IS STILL AN UPGLIDE COMPONENT INTO THE MOUNTAINS...SO WESTERN
CWFA WILL SEE CHANCES OF CONVECTION...DRY FORECAST ADVERTISED FOR
THE EASTERN ZONES...INCLUDING ALL OF INTERSTATE 77 CORRIDOR. ALSO
WENT SLIGHTLY WARMER EAST.

BENIGN WEATHER EXPECTED THURSDAY NITE THROUGH FRIDAY NITE AS DRIER
AIR EXPECTED TO INFILTRATE ALL OF THE CWFA...BUT DOES BEGIN RETURN
MODE LATE IN THE FRIDAY PERIOD. CANNOT RULE OUT A SHOWER OR
ISOLATED THUNDESTORM...ESPECIALLY IN UPSLOPE ENVIRONS...BUT FOR NOW
WILL MAINTAIN DRY FORECAST FOR THOSE PERIODS.

&&

.LONG TERM (SATURDAY THROUGH WEDNESDAY)...
EASTERLY FLOW AT LOW LEVELS...BETWEEN SURFACE RIDGE MOVING OFF NEW
ENGLAND COAST AND THE APPROACHING HURRICANE FRANCES...WILL PUMP
ATLANTIC MOISTURE UP THE EAST SLOPES OF THE APPALACHIANS SATURDAY
AND SUNDAY. EXPECT SCATTERED SHOWERS TO DEVELOP AT ANY TIME IN THE
PERIOD FROM MECHANICAL FORCING. TEMPS ARE CLOSE TO NEW GUIDANCE SO
EXPECT ONLY MINOR CHANGES.

FRANCES REMAINS THE PRIMARY CONCERN. MOST RECENT HPC MEDIUM RANGE
GUIDANCE IS SLOWER AND FARTHER WEST...BUT AGAIN...THERE REMAINS MUCH
UNCERTAINTY. PLEASE REFER TO THE OFFICIAL FORECAST FROM THE NATIONAL
HURRICANE CENTER FOR OFFICIAL TRACK INFORMATION. THE MEDIUM RANGE
GRIDS WILL REFLECT THE PASSAGE OF THE REMNANTS OF FRANCES ACROSS THE
WESTERN TIP OF NC TUESDAY EVENING AND NERN TN TUESDAY NITE. A MORE
WESTERN TRACK WOULD BRING MORE OF A SEVERE WEATHER/HEAVY RAIN
THREAT. WITH THAT IN MIND...HAVE STARTED TO RAMP UP POP HIGHER IN
THE CHANCE RANGE STARTING LATE MONDAY...AND HAVE EXTENDED POP THRU
DAY 6. HAVE RAISED MIN TEMPS A CATEGORY SUNDAY NIGHT AND LOWERED A
CATEGORY FOR MAX TEMPS MONDAY OWING TO MORE CLOUDS/PRECIP EXPECTED.
NEEDLESS TO SAY...EXPECT CHANGES.

&&

.AVIATION...
EXPECT PERSISTENT PATTERN OVER THE NEXT 24 HOURS. MVFR CEILINGS WILL
GRADUALLY IMPROVE THIS AFTERNOON AS CONVECTION CONTINUES TO FIRE.
HAZE HAS BEEN A PROBLEM BUT VISBY SHOULD IMPROVE TO 6 MILES AT MOST
SITES LATE THIS AFTERNOON. EXPECT CONVECTION TO CONTINUE WELL INTO
THE EVENING. LIKE THIS PAST MORNING...MVFR FOG AND CEILINGS SHOULD
ONCE AGAIN DEVELOP AFTER 06Z WITH WEAK UPSLOPE FLOW. THIS SHOULD
HANG ON INTO THE MIDDLE OF THE DAY THURSDAY.
&&

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

SHORT TERM...SAB
LONG TERM/AVIATION...PM

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
521 AM EDT WED SEP 1 2004

GAZ010-017-018-026-028-029-NCZ033>037-048>059-062>072-082-SCZ001>014-
019-020920-
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-
521 AM EDT WED SEP 1 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.

.DAYS TWO THROUGH SEVEN...

SCATTERED THUNDERSTORMS ARE EXPECTED THURSDAY SOUTH OF INTERSTATE
26...WITH ISOLATED THUNDERSTORMS BETWEEN INTERSTATE 26 AND INTERSTATE
40. ISOLATED THUNDERSTORMS ARE EXPECTED IN THE PIEDMONT
FRIDAY...SPREADING WEST ACROSS THE AREA FRIDAY NIGHT. SCATTERED
THUNDERSTORMS ARE GENERALLY EXPECTED SATURDAY THROUGH MONDAY.
HURRICANE FRANCES WILL APPROACH THE FLORIDA COAST BY THE WEEKEND.

.SPOTTER INFORMATION STATEMENT...