Hail and Damaging Winds in South Carolina, August 29, 2011

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
252 PM EDT MON AUG 29 2011

.SYNOPSIS...
A RIDGE OF HIGH PRESSURE WILL TO MOVE INTO THE CAROLINAS AND
DOMINATE OUR WEATHER THROUGH THE NEXT SEVERAL DAYS. A COLD FRONT IS
EXPECTED TO REACH THE AREA BY THE END OF THE HOLIDAY WEEKEND.

&&

.NEAR TERM /THROUGH TUESDAY/...
MID AFTERNOON SURFACE MAP FEATURES A NORTHEAST TO SOUTHWEST GRADIENT
OF MOISTURE AND STABILITY OVER THE CWA. SURFACE DEW POINTS IN THE
WEST ARE IN THE LOWER AND MIDDLE 50S WHILE EASTERN ZONES HAVE MID 60
DEW POINTS. ALONG WITH THIS MOISTURE TRANSITION... CAPES ARE CLOSE
TO 1000 J/KG IN THE EAST LOWERING TO LESS THAN 100 J/KG IN THE FAR
WEST. THE SHORT WAVE TROUGH ALOFT MOVING INTO THE AREA IS PRODUCING
UPWARD MOTION ACROSS THE CWA PER THE QG DIAGNOSTICS. THE COMBINATION
OF LIFT AND LIMITED INSTABILITY IS PROMOTING THE DEVELOPMENT OF
ISOLATED SHOWERS AND THERE COULD BE A FEW THUNDERSTORMS. MODEL
SOUNDINGS INDICATE THE INSTABILITY IS INSUFFICIENT TO PRODUCE VERY
STRONG UPDRAFTS... ALTHOUGH A STRONG STORM OR TWO COULD OCCUR IN THE
FAR EAST WHICH IS CLOSER TO THE MORE UNSTABLE AIR MASS NEAR THE
COAST. HIGH PRESSURE TO THE NORTH AND A WEAK LOW TO THE SOUTH WILL
PRODUCE LIGHT NORTHEAST SURFACE WIND INTO THE EVENING.

TONIGHT... THE SHORT WAVE TROUGH ALOFT WILL MOVE EAST OF THE AREA
OVERNIGHT TAKING WITH IT THE FORCING FOR UPWARD MOTION. ISOLATED
SHOWERS WILL CONTINUE INTO THE EVENING BUT GRADUALLY DISSIPATE.
MODELS ARE INDICATING LOW LEVEL MOISTURE WILL INCREASE SUFFICIENTLY
OVERNIGHT TO PRODUCE STRATUS AND STRATOCUMULUS CLOUDS. CLOUDS AND
LIGHT NORTHEAST WIND WILL LIKELY DIMINISH THE CHANCE OF FOG EAST OF
THE MOUNTAINS BUT MOUNTAIN VALLEYS LIKELY TO HAVE FOG FORM DURING
THE EARLY MORNING HOURS. MAXIMUM TEMPERATURES ON TUESDAY WILL BE IN
THE MID 80S OUTSIDE THE MOUNTAINS AND IN THE UPPER 70S AND LOWER 80S
IN THE MOUNTAINS.

&&

.SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY/...
AS OF 200 PM MON...A SE UPSLOPE FLOW WILL DEVELOP AROUND SFC HIGH
PRES TO THE NE TUE NIGHT...WITH UPSLOPE FLOW INCREASING INTO THE SRN
APPALACHIANS. INCREASING CLOUDS IN THE MOISTENING BOUNDARY LAYER
WILL BE THE MAIN CONSEQUENCE...BUT LIGHT PRECIPITATION COULD BE
WRUNG OUT ALONG THE UPSLOPE PREFERRED AREAS. THE NAM AND SREF
FEATURE THIS...SO WILL ADVERTISE MAINLY SLIGHT CHANCES FOR SHOWERS
IN ERN ESCARPMENT AREAS TOWARD DAYBREAK WED MORNING. THE MORNING
CLOUDS WILL LIFT AND SCATTER TO ALLOW INSTABILITY TO INCREASE
THROUGH THE AFTN HOURS AS TEMPS RISE A BIT ABOVE NORMAL. A SHORTWAVE
MAY BRUSH THE EXTREME NRN TIER OF THE FORECAST AREA DURING THE DAY
WED...BUT ANY BETTER FORCING WILL BE NORTH OF THE AREA. WILL CONFINE
WEDNESDAY POPS TO SLIGHT CHANCES IN MAINLY MTN AND NRN NC FOOTHILL
SECTIONS.

STRONGER HIGH PRESSURE WILL THEN RIDGE OVER INTO THE FORECAST AREA
WED NIGHT THROUGH THU. DESPITE THE RIDGING...DEEPER LAYER MOISTURE
WILL ACTUALLY INCREASE IN THE PROFILES. LOW LEVEL WIND CONVERGENCE
AND DIFFERENTIAL HEATING WILL PROVIDE THE MAIN FORCING...WITH CHC
MTN POPS AND SCHC POPS OVER THE ADJACENT FOOTHILLS THROUGH THU AFTN.
TEMPS SHOULD WARM A DEGREE OR TWO MOST AREAS EXCEPT THE NC PIEDMONT.

&&

.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
AS OF 130 PM MONDAY...NO MAJOR CHANGES WERE MADE TO THE EXT RANGE.
THE MODELS CONTINUE TO AGREE WELL WITH THE STRENGTHENING RIDGE OFF TO
THE WEST THU AND A GENERAL SUBSIDENCE ZONE ENGULFING THE CWFA. THE
HPC HAS PUT MUCH STOCK IN THE ECMWF AND ECMWF ENS CITING PREVIOUS
CONTINUITY...WHICH IS GOOD BECAUSE THE LATEST GFS IS SIMILAR WITH THE
MASS FIELDS AND UPPER ENERGY STRUCTURE WITH THE PATTERN AND EVENTUAL
FRONTAL SYSTEM BY DAY 7.

THE MID LEVELS REMAIN WARM THROUGH THE FIRST FEW DAYS OF THE FCST
PERIOD WITH WEAK UPPER ENERGY POCKETS TRAVERSING THE AREA. THIS WILL
LIMIT SBCAPE TO RATHER LOW VALUES OUTSIDE THE MTNS THROUGH SAT...SO
SLIGHT CHC POPS ARE GOOD THERE. THE NC MTNS WILL HAVE A BIT ADDED
LIFT AND SCATTERED DIURNAL TSTMS EACH AFTERNOON BE BUMPED UP JUST A
BIT THERE. THE BIGGEST CHANGE WAS MADE WITH THE FROPA...EXPECTED
LATE SUN EARLY MON...AND POPS WERE BUMPED UP TO LOW END CHANCE
ACROSS THE CWFA DURING THIS TIME. THERE ISNT MUCH UPPER SUPPORT AND
H100-H50 Q/VECTOR CONV IS MINIMAL...HOWEVER A DECENT AMOUNT OF
SBCAPE AND TD POOLING AHEAD OF THE FRONT WILL MAKE FOR AN UNSTABLE
ATMOS AND A GOOD LINE OF ORGANIZED TSTMS ARE PROBABLE...SOME OF
WHICH COULD BE STRONG TO SEVERE.

MAX TEMPS WILL REMAIN ABOUT 5 DEGREES ABOVE NORMAL EACH AFTERNOON AND
LOWS WILL WILL REMAIN HIGH AS WELL WITH NO AIRMASS CHANGE AND A S/LY
LLVL FLOW IN PLACE. A MODERATE AIRMASS CHANGE AND INCREASED
CLOUDINESS ASSOCIATED WITH THE FROPA WILL RETURN MAX TEMPS TO AROUND
NORMAL FOR MON.

&&

.AVIATION /19Z MONDAY THROUGH SATURDAY/...
AT KCLT...SCATTERED TO OCCASIONALLY BROKEN CLOUDS BETWEEN 6K AND 8K
FT WILL PREVAIL DURING THE REST OF THE AFTERNOON. ISOLATED SHOWERS
AND THUNDERSTORMS WILL OCCUR IN THE PIEDMONT... BUT CONFIDENCE TOO
LOW TO INCLUDE IN TAF AT THIS TIME. NORTHEAST SURFACE WIND GENERALLY
LESS THAN 10 KT WILL CONTINUE INTO THE NIGHT. NORTHEAST FLOW WILL
TRANSPORT MOISTURE INTO THE TERMINAL AREA WHICH IS LIKELY TO
GENERATE STRATUS NEAR 5K FT BY 06Z LOWERING TO AROUND 15 HND FT BY
09Z. AFTER SUNRISE CLOUD BASES WILL GRADUALLY INCREASE TO 4K FT.

ELSEWHERE...SCATTERED TO BROKEN CLOUD 4K TO 6 KT WILL EXIST DURING
THE REMAINDER OF THE AFTERNOON. WIDELY SCATTERED SHOWERS AND
POSSIBLY A FEW THUNDERSTORMS ARE EXPECTED PRIMARILY EAST OF THE
MOUNTAINS. AFTER SUNSET SHOWERS WILL DIMINISH. AFTER 04Z STRATUS
NEAR 4K FT WILL GRADUALLY LOWER TO AROUND 15 HND FEET BY 09Z...
SPECIALLY EAST OF THE MOUNTAINS. VISIBILITY LESS THAN 3 MILES IN FOG
LIKELY IN MOUNTAIN VALLEYS BETWEEN 09Z AND 13Z.

OUTLOOK...ISOLATED SHRA AND SOME MORNING OBSCURATIONS IN FOG
POSSIBLE IN THE MTNS WEDNESDAY AND THURSDAY. OTHERWISE DRY WITH
FEW IF ANY RESTRICTIONS EXPECTED THROUGH SATURDAY.

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

&&

.CLIMATE...
GREENVILLE-SPARTANBURG HAS RECORDED HIGH TEMPERATURES OF 90 DEGREES
OR HIGHER 82 TIMES THIS YEAR AS OF AUGUST 29. THIS IS THE SECOND
GREATEST NUMBER OF 90 DEGREE OR WARMER DAYS IN ANY YEAR. THE
GREATEST NUMBER OF 90 DEGREE OR GREATER MAXIMUM TEMPERATURES WAS 84
BACK IN 1954.

&&

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

&&

SYNOPSIS...SBK
NEAR TERM...LGL
SHORT TERM...HG
LONG TERM...SBK
AVIATION...LGL
CLIMATE...HG/JAT

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
520 AM EDT MON AUG 29 2011

GAZ010-017-018-026-028-029-NCZ033-035>037-048>053-056>059-062>065-
068>072-082-501>510-SCZ001>014-019-300930-
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-
520 AM EDT MON AUG 29 2011

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

.DAY ONE...TODAY AND TONIGHT.

ISOLATED THUNDERSTORMS ARE EXPECTED TO DEVELOP THIS AFTERNOON AND
CONTINUE INTO THE EVENING. THE MAIN THREAT FROM THESE STORMS WILL
BE GUSTY WINDS AND CLOUD TO GROUND LIGHTNING.

.DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY.

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.SPOTTER INFORMATION STATEMENT...

NONE.

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
402 PM EDT MON AUG 29 2011

SCZ009-014-292045-
CHESTER-YORK-
402 PM EDT MON AUG 29 2011

...A STRONG THUNDERSTORM WILL AFFECT CHESTER AND SOUTHEASTERN YORK
COUNTIES THROUGH 445 PM EDT...

AT 401 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
STRONG THUNDERSTORM 3 MILES NORTH OF CHESTER...MOVING EAST AT 20 MPH.

PEOPLE IN CHESTER AND SOUTHEASTERN YORK COUNTIES...INCLUDING THE
FOLLOWING LOCATIONS...

CHESTER...LOWRYS AND CATAWBA...

SHOULD MONITOR THE WEATHER SITUATION CLOSELY. LISTEN FOR POSSIBLE
WARNINGS AND BE PREPARED TO TAKE APPROPRIATE ACTION SHOULD SEVERE
WEATHER THREATEN.

SMALL HAIL...AND WIND GUSTS UP TO 40 MPH ARE EXPECTED WITH THIS
STORM.

LAT...LON 3467 8088 3458 8142 3464 8142 3465 8143
      3480 8146 3506 8090 3486 8086 3484 8086
      3482 8089 3477 8086 3474 8087 3470 8085

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