Heavy Rain in North Carolina, August 22, 2012

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
432 PM EDT WED AUG 22 2012

.SYNOPSIS...
A WEAK FRONT WILL DRIFT EAST OVER THE CAROLINA COAST THROUGH
TONIGHT. BEHIND THE FRONT...WEAK HIGH PRESSURE WILL BUILD OVER THE
REGION FROM THE NORTH THROUGH THE REST OF THIS WEEK.

&&

.NEAR TERM /THROUGH THURSDAY/...
AS OF 430 PM...THE FORECAST HAS BEEN UPDATED TO INCREASE POPS EAST
OF INTERSTATE 77 WHERE THE BEST UPPER JETLET SUPPORT
PERSISTS...OTHERWISE IT IS ON TRACK. SOUNDINGS CONTINUE TO SHOW
LITTLE IN THE WAY OF FUTURE CONVECTIVE DEVELOPMENT...WITH MAINLY
ISOLD TO SCT COVERAGE OF WEAK SHOWERS. EXPECT THIS ACTIVITY TO
GRADUALLY SHIFT EAST OVERNIGHT AND DISSIPATE...WITH PERHAPS A COUPLE
LINGERING -SHRA/S JUST AHEAD OF THE TROF AXIS. THE DEEPER LAYERED
CLOUD COVER WILL DECREASE FROM THE WEST AS THE H5 AXIS PUSHES EAST
AND A LLVL HIGH BUILDS IN. THERE COULD BE PRETTY GOOD RADIATIONAL
COOLING ACROSS THE MTNS...SO A DENSE FG THREAT IS NOT OUT OF THE
QUESTION ACROSS THE MTN VALLEYS AND NC FOOTHILLS. MINS SHOULD DROP
TO A FEW DEGREES BELOW NORMAL.

ON THURSDAY...UPPER SUPPORT OF CONVECTION WILL BECOME LESS AND LESS
AS THE DAY PROGRESSES. THE MODELS AGREE THAT ANY S/W DPVA WILL
AFFECT AREAS TO THE EAST OF THE CWFA...WHILE THE TROF LINGERS
OVERHEAD YET BROADENS AND WEAKENS. THERE SHOULD BE ENOUGH LLVL
MOISTURE AND DEEP ENOUGH NE/LY FLOW TO INSTIGATE ISOL AFTERNOON
SHRA...MAINLY ACROSS THE HIGHER TERRAIN. WITH BETTER INSOLATION...A
COUPLE THUNDERSTORMS ARE ALSO POSSIBLE...BUT NOTHING STRONG TO
SEVERE SHOULD BE ABLE TO DEVELOP. MAX TEMPS WILL STILL BE HELD A
COUPLE DEGREES BELOW NORMAL AS A GOOD NE/LY TO E/LY FLOW CONTINUES.

&&

.SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY/...
AS OF 230 PM EDT WEDNESDAY...STILL NOT SEEING A LOT TO GRAB ONTO AS
FAR AS FORCING FOR FRIDAY AND SATURDAY. SLIGHT EASTERLY FLOW WILL
CONTINUE AS SURFACE RIDGE REMAINS IN PLACE OVER NORTHEAST COAST.
THIS WILL AID DEVELOPMENT OF DIURNAL CONVECTION...BUT MOSTLY OVER
THE MOUNTAINS. BETTER CAPE AND MOISTURE ON FRIDAY SO FOCUSED BEST
PRECIP CHANCES THAT AFTERNOON...BUT FELT COMFORTABLE WITH SLIGHT
CHANCES SATURDAY.

&&

.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
AS OF 230 PM EDT WEDNESDAY...MORE OR LESS ZONAL FLOW ALOFT EXPECTED
ACROSS MUCH OF THE CONUS SUNDAY. RIDGE OVER THE PLAINS BEGINS
DEEPENING MONDAY AS TROUGH AND WEAK SURFACE LOW PRESSURE DEVELOP
OVER EASTERN GREAT LAKES. WEAK SURFACE BOUNDARY APPEARS TO STALL
JUST NORTH OF THE CAROLINAS BY MIDWEEK. PUT IN CHANCE POPS TOWARD
THE END OF THE PERIOD TO REFLECT THIS. HPC TRACK OF TS ISAAC WOULD
BRING THE STORM OVER GEORGIA BY EARLY WEDNESDAY...BUT GIVEN THE WIDE
SPREAD IN MODEL SOLUTIONS THERE IS LOW CONFIDENCE THAT WOULD OCCUR.
HOWEVER...THE RESULTING UPSLOPE FLOW IF THAT TRACK VERIFIES...AND
POTENTIAL INTERACTION OF ISAAC WITH THE STALLED BOUNDARY...WOULD BE
A CAUSE FOR CONCERN IN THE WESTERN CAROLINAS. WILL NEED TO WATCH
TRACK FORECASTS CLOSELY.

&&

.AVIATION /21Z WEDNESDAY THROUGH MONDAY/...
AT KCLT...LOW TOP SHOWERS HAVE NOT FILLING IN AS RAPIDLY AS EXPECTED
DESPITE THE WEAK UPPER SUPPORT. WILL RIDE ON MAINLY VCSH THROUGH THE
EARLY EVENING WITH NO RESTRICTIONS. THERE COULD BE SOME MVFR
STRATOCUMULUS IN THE AM...BUT THERE IS NOT ENOUGH CONFIDENCE TO
INCLUDE IN TAF AT THIS TIME...AS MODEL SOUNDINGS DISAGREE WITH
MOISTURE AND KEEP HIGHEST AMOUNTS JUST ABOVE 3 KFT.

ELSEWHERE...HIGHER VFR CIGS AT ALL TAF SITES REMAIN...WITH A SMALL
CHANCE OF A TERMINAL BEING AFFECTED BY SHOWERY ACTIVITY THROUGH THE
EVENING. DID INCLUDE VCSH AT THE NC SITES AND A POSSIBLE MVFR CIG
AND VSBY ARE NOT OUT OF THE QUESTION. EXPECT DECREASING CLOUD COVER
AND PERHAPS SOME MVFR/IFR STCU BY MORNING...ESP ACROSS KAVL AND
KHKY. VSBY/S WILL LIKELY DROP TO IFR AT KAVL BY EARLY MORNING AS THE
BETTER DRYING ALOFT WILL OCCUR OVER THAT AREA.

OUTLOOK...ISOLATED AFTN TSTMS ARE EXPECTED THURSDAY AND FRIDAY...
MAINLY OVER THE MTNS. MORNING FOG IS LIKELY IN THE FRENCH BROAD
VALLEY AND A BRIEF PERIOD OF MORNING FOG IS POSSIBLE AT SOME OF THE
FOOTHILL AND PIEDMONT TAF SITES JUST ABOUT ANY DAY.

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...JOH
NEAR TERM...HG/SBK
SHORT TERM...JW
LONG TERM...JW
AVIATION...SBK

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
323 PM EDT WED AUG 22 2012

GAZ010-017-018-026-028-029-NCZ033-035>037-048>053-056>059-062>065-
068>072-082-501>510-SCZ001>014-019-232000-
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-
323 PM EDT WED AUG 22 2012

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

.DAY ONE...THIS AFTERNOON AND TONIGHT.

SCATTERED TO ISOLATED THUNDERSTORMS WILL DEVELOP ACROSS THE
WESTERN CAROLINAS AND NORTHEAST GEORGIA THIS AFTERNOON AND EVENING.
OCCASIONAL CLOUD TO GROUND LIGHTNING WILL BE THE PRIMARY THREAT
WITH THESE STORMS. SLOW MOVING STORMS OVER URBAN AREAS AND OTHER
POORLY DRAINED AREAS COULD RESULT IN EXCESSIVE RAINFALL.

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

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.SPOTTER INFORMATION STATEMENT...

NONE.

WIMBERLEY