Special Weather Statement, NWS Greenville-Spartanburg, SC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
335 AM EDT WED AUG 8 2012

.SYNOPSIS...
A WEAK STATIONARY FRONT WILL DISSIPATE OVER THE REGION TODAY...BEING
REPLACED BY WEAK HIGH PRESSURE FOR THURSDAY.  A COLD FRONT WILL PUSH
ACROSS THE AREA FROM THE WEST LATE FRIDAY. DRY HIGH PRESSURE WILL
THEN BUILD BEHIND THE FRONT OVER THE WEEKEND.

&&

.NEAR TERM /THROUGH TONIGHT/...
THE NEXT IN A SERIES OF WEAK RIPPLES IS PROGGED TO MOVE ACRS THE
REGION LATER TODAY. THE ADVERTISED LOWERING OF PWAT VALUES IS
EXPECTED TO KEEP DIURNAL TSTM CVRG SCATTERED. FCST SNDGS ARE SHOWING
MODEST MID-LVL LAPSE RATES BUT DECENT ENUF MID-LVL DRY AIR TO
POTENTIALLY ENHANCE DOWNDRAFTS. COMBINED WITH SEASONABLY HIGH WET
BULB ZERO HEIGHTS...A FEW STRONG STORMS ARE POSSIBLE. HIGHER LVL
CLOUD SHIELD IS EXPECTED TO CONTINUE TO ROTATE DOWNSTREAM OF THE
CWFA THIS MORNING AND WHATEVER THE EXTENT OF PRE-DAWN LOW CLOUDS
AND FOG WINDS UP BEING...DEVELOPING SUNSHINE IS ON TAP THEREAFTER.
MOS BLEND SUPPORTS AN UPWARD NUDGE TO MAX TEMPS...PROGGED TO BE
RIGHT AROUND NORMAL. IN A CHANGE FROM THE PAST FEW NIGHTS...WITH
RELATIVELY DRIER AIR IN PLACE THRU A DEEP LAYER...TSTM ACTIVITY
SHOULD BE ABLE TO DIMINISH WITH LOSS OF HTG THIS EVENING.

&&

.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 300 AM WEDNESDAY...AN UNSEASONABLY STRONG SHORTWAVE TROF WILL
DIG ACRS THE GREAT LAKES AND OHIO VALLEY ON THURSDAY...WITH HEIGHTS
BEGINNING TO FALL ACRS THE CWFA. FCST SNDGS SHOW LESS INSTBY THAN
WEDNESDAY HOWEVER...WITH WEAK SHEAR. STILL EXPECT DECENT
DESTABILIZATION AND SCATTERED MTN CONVECTION WITH LESS COVERAGE ACRS
THE PIEDMONT. A FEW WET MICROBURSTS CAN BE EXPECTED THU AFTN/EARLY
EVE. HIGH TEMPS NEAR NORMAL.

THURSDAY NIGHT THRU FRIDAY NIGHT...THE SHORTWAVE TROF WILL CONTINUE
TO DIG AND CLOSE OFF INTO AN UPR LOW OVR THE GREAT LAKES. THE ECMWF
SOLN WAS THE MODEL OF CHOICE BY HPC WITH THIS FEATURE...AND HAS A
MODERATELY-FORCED COLD FRONT ENTERING THE MTNS FRI AFTN AND CROSSING
THE PIEDMONT FRI EVE. FCST SNDGS DO NOT LOOK IMPRESSIVE FOR
SEVERE...WITH ONLY 1500-2000 J/KG OF CAPE AND 20-30 KTS OF 0-6KM
BULK SHEAR. THE MAIN CONCERN IS THAT PRE-FRONTAL CLOUDS/PRECIP MAY
LIMIT DESTABILIZATION WITH THE FRONT. HOWEVER...BEING A MORE
SOUTHERN SOLN WITH THE UPR LOW...THE ECMWF BRINGS STRONG DEEP Q
CONVERGENCE WITH THE FRONT AND DECENT UPR JET DIVERGENCE. SO WILL
KEEP MENTION OF SEVERE POTENTIAL IN THE HWO FOR FRI-FRI NGT WITH THE
FRONT. TEMPS NEAR NORMAL FOR LOWS AND A CATEGORY OR TWO BELOW NORMAL.

&&

.LONG TERM /SATURDAY THROUGH TUESDAY/...
AS OF 330 AM WEDNESDAY...THE FCST WAS LEFT UNCHANGED FROM SATURDAY
ONWARD...AS THE LATEST GUIDANCE DID NOT SIGNIFICANTLY CHANGE FROM
PREVIOUS RUNS. SATURDAY AND SUNDAY STILL LOOK RELATIVELY PLEASANT
FOR EARLY AUGUST...WITH TEMPS A CATEGORY OR SO BELOW NORMAL...AND
BELOW NORMAL HUMIDITY AND POPS.

PREVIOUS DISCUSSION...
AS OF 145 PM TUESDAY...TROUGH AXIS AND COLD FRONT WILL PUSH ACROSS
THE AREA FRIDAY NIGHT INTO EARLY SATURDAY...WITH SOLID CHANCE/LIKELY
POPS LINGERING INTO FRIDAY EVENING. THE GLOBAL MODELS ARE IN DECENT
AGREEMENT IN STALLING THE FRONT SOUTH OF THE CWFA OVER THE
WEEKEND...WITH MUCH DRIER AIR ADVECTING INTO THE AREA. AFTER A
STORMY FRIDAY/FRI NIGHT...THE WEEKEND MAY TURN OUT TO BE QUITE
PLEASANT...WITH TEMPS AVERAGING A LITTLE BELOW NORMAL...AND POPS/
POSSIBLY RH AVERAGING MUCH BELOW NORMAL.

THE MODELS SUGGEST AIR MASS MODIFICATION WILL OCCUR QUICKLY IN THE
WAKE OF THE DEPARTING TROUGH...AS BERMUDA HIGH ALLOWS LOW LEVEL
MOISTURE/INSTABILITY TO RETURN. A MORE TYPICAL SUMMERTIME PATTERN
SHOULD YIELD MORE TYPICAL SUMMERTIME CONDITIONS...WITH ISOLATED TO
WIDELY SCATTERED DIURNAL CONVECTION EXPECTED ON DAYS 6/7. TEMPS WILL
ALSO LIKELY TO CLIMB TO NEAR NORMAL LEVELS BY THIS TIME.

&&

.AVIATION /08Z WEDNESDAY THROUGH SUNDAY/...
AT KCLT...CONSIDERABLE MID AND HIGH LVL CLOUDS WILL STEADILY ROTATE
OFF TO THE EAST TOWARD DAYBREAK. WITHIN THE VERY WEAK AND MOIST BLYR
REGIME...SOME DEGREE OF PRE-DAWN FOG AND LOW CLOUD DEVELOPMENT
REMAINS PROBABLE AND THE 04 UTC LAMP GUIDANCE SUPPORTS THE GOING
FCST OF A PERIOD OF IFR CIGS AND MVFR VSBY UNTIL ABT MID-MORNING.
SCATTERED PIEDMONT TSTMS ARE STILL EXPECTED FROM ABT MID-AFTERNOON
UNTIL MID-EVENING. WINDS WILL BE QUITE LIGHT THROUGH THE
PERIOD...TENDING FROM THE SW DURING THE DAY.

ELSEWHERE...FLIGHT RESTRICTIONS ARE EXPECTED TO BECOME WIDESPREAD AS
THE OVERNIGHT HOURS WEAR ON WITHIN THE MOIST BOUNDARY LAYER AND
WEAK FLOW REGIME. BY 14-15 UTC...VFR CONDS SHOULD BECOME
INCREASINGLY PREVALENT AS DEEPER MOISTURE MOVES TO THE EAST OF THE
FA. THE JURY IS STILL OUT ON AFTERNOON/EVE TSTM CVRG...AND WILL
CONTINUE TO MENTION VCTS FOR ALL TERMINALS FOR NOW.

OUTLOOK...A MORE NORMAL SUMMERTIME DIURNAL TSTM PATTERN IS EXPECTED
AGAIN ON THURSDAY. A COLD FRONT WILL APPROACH FROM THE NW ON FRI TO
INCREASE THUNDERSTORM COVERAGE THROUGH FRI NIGHT. DRIER HIGH PRES
WILL RETURN OVER THE WEEKEND.

AN EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLE SHOWING THE
PERCENTAGE OF GUIDANCE MEMBERS AGREEING WITH THE SCHEDULED ISSUANCE
CATEGORY IS AVAILABLE AT FOLLOWING LINK (USE LOWER CASE)...

WWW.WEATHER.GOV/GSP/AVIATION/TABLES.HTM

&&

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

&&

SYNOPSIS...ARK
NEAR TERM...CSH
SHORT TERM...ARK
LONG TERM...ARK/JDL
AVIATION...CSH

HAZARDOUS WEATHER OUTLOOK...CORRECTED
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
443 AM EDT WED AUG 8 2012

GAZ010-017-018-026-028-029-NCZ033-035>037-048>053-056>059-062>065-
068>072-082-501>510-SCZ001>014-019-090845-
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-
443 AM EDT WED AUG 8 2012

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

.DAY ONE...TODAY AND TONIGHT.

SCATTERED THUNDERSTORMS ARE EXPECTED TO DEVELOP ACROSS THE REGION
THIS AFTERNOON INTO THIS EVENING. A FEW STORMS MAY BE STRONG
ENOUGH TO PRODUCE LOCALLY DAMAGING WIND GUSTS AND LARGE HAIL.

.DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY.

A STRONG COLD FRONT WILL APPROACH THE REGION LATE FRIDAY. THERE
IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ASSOCIATED WITH THE
FRONT. DAMAGING WIND GUSTS WILL BE THE PRIMARY THREAT.

.SPOTTER INFORMATION STATEMENT...

SKYWARN SPOTTERS ARE REQUESTED TO FORWARD ANY REPORTS OF LARGE
HAIL...DAMAGING WINDS...TORNADOES OR FLASH FLOODING TO OUR OFFICE.

ARK

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
1217 AM EDT WED AUG 8 2012

SCZ002-003-080545-
GREENVILLE MOUNTAINS-PICKENS MOUNTAINS-
1217 AM EDT WED AUG 8 2012

...STRONG THUNDERSTORMS WILL AFFECT NORTHERN GREENVILLE AND NORTHERN
PICKENS COUNTIES THROUGH 145 AM EDT...

AT 1211 AM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
STRONG THUNDERSTORMS PRODUCING HEAVY RAINFALL ALONG A LINE EXTENDING
FROM 3 MILES NORTHEAST OF NINE TIMES TO 3 MILES NORTHEAST OF
TIGERVILLE. THESE STORMS WERE NEARLY STATIONARY.

HEAVY RAINS MAY FLOOD AREAS WITH POOR DRAINAGE...SUCH AS DITCHES AND
UNDERPASSES. AVOID THESE AREAS AND DO NOT CROSS FLOODED ROADS. WATER
LEVELS OF SMALL STREAMS AND RIVERS MAY ALSO RISE RAPIDLY. SEEK HIGHER
GROUND IF THREATENED BY FLOOD WATERS.

LAT...LON 3507 8273 3519 8222 3506 8231 3487 8289

KRENTZ

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
613 AM EDT WED AUG 8 2012

NCZ048-081100-
MADISON-
613 AM EDT WED AUG 8 2012

...A STRONG THUNDERSTORM WILL AFFECT NORTHERN MADISON COUNTY THROUGH
700 AM EDT...

AT 607 AM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
STRONG THUNDERSTORM PRODUCING HEAVY RAIN 3 MILES NORTH OF
WHITEROCK...OR 14 MILES NORTH OF MARSHALL...MOVING EAST AT 10 MPH.

HEAVY RAINS MAY FLOOD AREAS WITH POOR DRAINAGE...SUCH AS DITCHES AND
UNDERPASSES. AVOID THESE AREAS AND DO NOT CROSS FLOODED ROADS. WATER
LEVELS OF SMALL STREAMS AND RIVERS MAY ALSO RISE RAPIDLY. SEEK HIGHER
GROUND IF THREATENED BY FLOOD WATERS.

LAT...LON 3604 8259 3597 8260 3596 8256 3598 8251
      3595 8248 3593 8250 3591 8249 3589 8244
      3580 8250 3591 8287 3595 8285 3593 8281
      3601 8277 3607 8264

ARK