Flash Flood Warning 20, NWS Greenville-Spartanburg, SC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
926 PM EDT SUN JUN 23 2013

.SYNOPSIS...
A BERMUDA HIGH OFF THE CAROLINA COAST WILL HELP PUMP A MOIST
SOUTHERLY FLOW INTO THE AREA THROUGH THE END OF NEXT WEEK. AS THIS
MOISTURE INCREASES AFTERNOON SHOWERS AND THUNDERSTORMS WILL ALL SO
INCREASE IN COVERAGE ACROSS THE CAROLINAS. A COOL FRONT IS EXPECTED
TO ENTER THE PICTURE FOR THE WEEKEND.

&&

.NEAR TERM /THROUGH MONDAY/...
AS OF 915 PM EDT SUNDAY...LIGHT SOUTHWEST FLOW AND A BOOST FROM AN
OUTFLOW BNDRY THAT MOVES INTO THE MTNS RECENTLY CONTINUES TO SUPPORT
CONVECTION ALONG AND NEAR THE BLUE RIDGE. THE FORCING SHOULDN/T BE
STRONG ENOUGH TO MAINTAIN THIS CONVECTION FOR MORE THAN ANOTHER
HOUR...POSSIBLY TWO. THAT/S ALSO WHAT THE 4KM SPC WRF WAS
SHOWING...SO CONFIDENCE IN CONVECTION DYING OFF BY MIDNIGHT IS GOOD.
THE ONLY CONCERN IS THAT LAPS CAPES REMAIN HIGH OVER THE WRN UPSTATE
AND NE GA AND OUTFLOW WILL WORK SOON INTO THESE AREAS FROM THE
SOUTHWEST. THEREFORE I HOLD ON TO LOW POPS DOWN THAT WAY THE
LONGEST. STILL...FOR THE MOST PART...I/VE ADJUSTED POPS DOWN
OVERNIGHT.

AS OF 645 PM EDT SUNDAY...LAPS IS SHOWING THAT SB CAPE HAS INCREASED
TO AROUND 2500 J/KG OVER THE UPSTATE AND SRN NC PIEDMONT. THERE IS
EVEN SOME RATHER DENSE CAPE BETWEEN -20 DEG C AND -40 DEG C. AND
SURE ENOUGH WE HAVE HAD ONE SEVERE STORM WITH AN INTENSE LOOKING
HAIL CORE OVER ERN SPARTANBURG COUNTY IN THE LAST FEW MINUTES. THIS
AREA ROUGHLY EAST OF GREENVILLE...UP TO THE BLUE RIDGE AND EAST TO
AROUND GAFFNEY AND SHELBY WILL SEE NUMEROUS STORMS OVER THE NEXT FEW
HOURS AND THE GRIDS HAVE BEEN UPDATED TO REFLECT THIS.

AS OF 420 PM EDT SUNDAY...TRIMMED POPS BACK ACROSS THE FOOTHILLS FOR
THE NEXT HOUR...BUT AS THE DAY SHIFT NOTED...OUTFLOW BNDRYS
APPROACHING FROM THE SOUTH SHOULD TRIGGER MORE CONVECTION IN THIS
AREA IN SHORT ORDER....ESPECIALLY ACROSS UPSTATE SOUTH CAROLINA AND
FARTHER EAST ACROSS THE NORTHEAST PIEDMONT OF SOUTH
CAROLINA...ROUGHLY ALONG A LINE FROM GREENVILLE TO ROCK HILL.

AS OF 245 PM...LATEST WATER VAPOR IMAGES CONTINUED TO INDICATE THAT
THE CENTER OF THE MID LEVEL VORT MAX WAS TRACKING NW ACROSS KY.
REGIONAL RADAR INDICATED THAT SHRA AND TSRA HAVE DEVELOPED ACROSS
THE CENTRAL CAROLINAS AND EASTERN PIEDMONT...WITHIN A REGION OF WEAK
MOISTURE CONVERGENCE. ANOTHER BKN BAND OF SHRA AND TSRA HAS
DEVELOPED OVER THE EAST FACING SLOPES OF THE NC MTNS AND FOOTHILLS.
OBSERVED 12Z SOUNDINGS AT KFFC AND KGSO INDICATED THAT STORM MOTIONS
WILL FAVOR THE CURRENT ACTIVITY TO DRIFT NORTHWARD THROUGH THE
REMAINDER OF THIS AFTERNOON. SOUNDINGS ALSO REVEAL FZL ABOVE 13.5
KFT...PW VALUES GREATER THE 1.4 INCHES...CAPE VALUES BETWEEN
1500-2000 J/KG...MINIMAL CIN. GIVEN THE WEAK UPPER SUPPORT...UPSLOPE
FLOW...AND GRADUAL INCREASING OF LLVL MOISTURE CONVERGENCE...SHRA
AND TSRA COVERAGE SHOULD INCREASE THROUGH THIS AFTERNOON.

THROUGH 5 PM...I WOULD EXPECT THE CLUSTER OF SHRA/TSRA OVER CLT TO
SLOWLY DRIFT NORTH. HOWEVER...CONVECTION WILL LIKELY ENCOUNTER LESS
INSTABILITY AND LLVL CONVERGENCE...ERODING SOME OF THE COVERAGE N OF
I-40. HOWEVER...CONVECTION OVER THE CENTRAL SC WILL MOVE OVER THE
UPSTATE...POSSIBLY INCREASING IN COVERAGE. MTN COVERAGE WILL LIKELY
REMAIN...WITH SLIGHT DECREASE NEAR THE TN BORDER.

OVERNIGHT...SOME OF THE CONVECTION ALLOWING MODELS INDICATES THAT
THE CURRENT COVERAGE WILL NOT SURVIVE PAST THE PRIME DIURNAL TIMING.
THIS APPEARS POSSIBLE GIVEN THE LACK OF UPPER SUPPORT. HOWEVER...VIS
SATELLITE INDICATES THAT THE SEA BREEZE IS TRACK NW ACROSS THE
COASTAL PLAIN. THE WINDS THIS EVENING AND TONIGHT WOULD FAVOR THE
BOUNDARY CONTINUING TO MOVE NW. THE COMBINATION OF THE REMNANT SEA
BREEZE AND LINGERING CAPE WOULD EASILY SUPPORT ISO SHRA/TSRA
OVERNIGHT...THEREFORE I WILL KEEP POPS SCHC OVERNIGHT. MIN TEMPS
NEAR NORMAL.

MONDAY...THE ENVIRONMENT WILL CHANGE VERY LITTLE FROM TODAY. THE
REGION WILL REMAIN ON THE WESTERN EDGE OF THE BERMUDA HIGH...KEEPING
FZL...CAPE...AND PW VERY SIMILAR. I WILL INDICATE A DIURNAL PEAK TO
40 PERCENT ACROSS THE CWA. HIGH TEMPERATURES WILL LIKELY RANGE
WITHIN A DEGREE OR TWO OF TODAY/S VALUES.

&&

.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY/...
AS OF 155 PM SUNDAY...A RELATIVE WEAKNESS IN THE UPPER HEIGHT FIELD
WILL REMAIN OVER THE TENN VALLEY/SOUTHERN APPALACHIANS REGION
THROUGH AT LEAST THE FIRST HALF OF THE SHORT TERM...BUT IS EXPECTED
TO GRADUALLY SHIFT EAST BY MID-WEEK. MEANWHILE...BERMUDA HIGH WILL
CONTINUE TO MAINTAIN SEASONABLY WARM/MOIST CONDITION ACROSS THE
REGION THROUGH THE PERIOD. DEVELOPING WESTERLY FLOW NEAR THE TOP OF
THE BOUNDARY LAYER WILL SUPPORT LEE/PIEDMONT TROUGH FORMATION...
WHICH WILL ACT AS A FOCUS FOR DIURNAL CONVECTION TUE AND WED. POPS
WILL BE ADVERTISED A LITTLE ABOVE CLIMO TUE AFTERNOON/EVENING...THEN
DIMINISH TO NEAR-CLIMO WED...AS THE PATTERN ALOFT BECOMES NOMINALLY
LESS FAVORABLE FOR CONVECTION. OVERALL...THE FORECAST HOLDS LITTLE
IN THE WAY OF SURPRISES FOR LATE JUNE IN THE WESTERN CAROLINAS AND
NORTH GA.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
AS OF 200 PM SUNDAY...LITTLE CHANGE IN THE TYPICAL SUMMERTIME
PATTERN IS EXPECTED DURING THE FIRST HALF OF THE MEDIUM RANGE...AS
THE AREA WILL REMAIN ON THE PERIPHERY OF THE UPPER RIDGE. NEAR-CLIMO
TEMPS AND POPS CAN BE EXPECTED THROUGH FRIDAY OR SO. FOR NEXT
WEEKEND...THE GLOBAL MODELS CONTINUE TO DEPICT MAJOR HEIGHT FALLS
OCCURRING...WITH ESTABLISHMENT OF AN EASTERN CONUS LONG WAVE TROUGH
ANTICIPATED. THE ECMWF AND GFS APPEAR TO BE CONVERGING TOWARD A
CONSENSUS SOLUTION OF AN ATTENDANT FRONTAL ZONE IMPACTING THE AREA
ON SATURDAY...WITH POSSIBLY SOME DEGREE OF DRYING ON SUNDAY.
HOWEVER...TIMING IS STILL VERY MUCH A CONCERN...AND POPS WILL BE
ADVERTISED IN THE SOLID CHANCE RANGE BOTH SATURDAY AND SUNDAY...WITH
A SLIGHT LEAN TOWARD HIGHER POPS ON SATURDAY.

&&

.AVIATION /02Z MONDAY THROUGH FRIDAY/...
AT KCLT...THE ATMOSPHERE IS STILL UNSTABLE...BUT IT APPEARS THAT
CONVECTION HAS MISSED THE AIRFIELD THIS EVENING. I WILL KEEP A
PERIOD OF VCSH TO ACCOUNT FOR A FEW LIGHT SHOWERS IN THE REGION.
OTHERWISE LOOK FOR SCT STRATO-CU AND A HIGHER ALTO-CU CIG FOR
SEVERAL HOURS. STILL EXPECTING MVFR CIGS TO DEVELOP LATER TONIGHT
WITH A MOIST SOUTHWEST FLOW. SOME OF THE GUIDANCE IS INDICATING THAT
A MUCH LOWER CIG COULD DEVELOP. HOWEVER...THE MODEL SOUNDINGS LOOK
TO BE CLOSER TO 2000 FEET. WITH THE WEAK WINDS WE MAY NOT SEE A LOW
CIG AT ALL. SO WHILE IT/S A LOW CONFIDENCE FORECAST...THAT 2KFT DECK
IS ABOUT THE BEST I CAN DO. WINDS WILL BE LIGHT OUT OF THE SOUTH TO
SOUTHEAST OVERNIGHT TURNING TO THE SSW MID-MORNING TMRW. WE SHOULD
SEE SCT TSTMS AGAIN TMRW AFTN. COVERAGE PROBABLY WON/T BE A GREAT AS
TODAY...BUT IT MERITS A PROB30 GROUP.

ELSEWHERE...VERY SIMILAR TO KCLT. TSTMS WILL CONTINUE JUST TO THE
NORTH OF KGSP AND KGMU FOR ANOTHER HOUR OR TWO. OUTFLOW BNDRYS
MOVING ACROSS KHKY MAY ALSO TRIGGER A TSTM OVER THE NEXT COUPLE
HOURS. CONFIDENCE IS NOT GREAT THAT AN MVFR DECK WILL DEVELOP
TONIGHT...BUT USING A BLEND OF MODEL GUIDANCE AND SOUNDINGS THAT/S
THE BEST I CAN COME UP WITH. WE VERY WELL COULD SEE A LOWER
CIG...BUT WITH ONLY 10 KTS OF FLOW IN THE LOWEST COUPLE KFT AND A
MOIST DEEP LAYER PROFILE...I DON/T THINK THAT/S LIKELY. SCT TSTMS
WILL DEVELOP AGAIN TMRW AND A PROB30 GROUP HAS BEEN ADDED TO THE
TAFS.

OUTLOOK...THE WESTERN CAROLINAS WILL REMAIN ON THE WESTERN EDGE OF A
BERMUDA HIGH THROUGH THE FIRST HALF OF THE WEEK. THE FLOW AROUND
THE HIGH WILL KEEP THE SOUTHEAST UNDER DEEP MOISTURE. THIS PATTERN
MAY SUPPORT DIURNAL SHRA/TSRA ALONG WITH DAWN FOG AND CIG
RESTRICTIONS EACH DAY.

CONFIDENCE TABLE...

            01-07Z        07-13Z        13-19Z        19-01Z
KCLT       HIGH  93%     MED   72%     HIGH  89%     HIGH 100%
KGSP       HIGH  95%     MED   76%     MED   69%     HIGH 100%
KAVL       HIGH  80%     MED   75%     MED   69%     HIGH 100%
KHKY       HIGH  93%     MED   65%     HIGH  94%     HIGH 100%
KGMU       HIGH  94%     MED   75%     MED   70%     HIGH 100%
KAND       HIGH  88%     MED   62%     MED   71%     HIGH  98%

THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE
HOURLY EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE
FORECASTS ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)

WWW.WEATHER.GOV/GSP/AVIATION_TABLES

&&

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

&&

SYNOPSIS...PAT
NEAR TERM...MCAVOY/NED
SHORT TERM...JDL
LONG TERM...JDL
AVIATION...MCAVOY

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
423 PM EDT SUN JUN 23 2013

GAZ010-017-018-026-028-029-NCZ033-035>037-048>053-056>059-062>065-
068>072-082-501>510-SCZ001>014-019-242030-
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-
423 PM EDT SUN JUN 23 2013

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

.DAY ONE...TONIGHT.

SCATTERED THUNDERSTORMS WILL CONTINUE TO DEVELOP ACROSS THE AREA
THROUGH THIS EVENING. ANY THUNDERSTORMS WILL MOVE SLOWLY AND
PRODUCE LOCALLY HEAVY RAINFALL ALONG WITH CLOUD TO GROUND
LIGHTNING STRIKES. BRIEFLY GUSTY WINDS WILL BE POSSIBLE AS WELL.

.DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY.

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.SPOTTER INFORMATION STATEMENT...

NONE.

LANE

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
746 PM EDT SUN JUN 23 2013

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0648 PM     TSTM WND DMG     2 S COWPENS             34.99N 81.80W
06/23/2013                   SPARTANBURG        SC   LAW ENFORCEMENT

            TREE BLOWN DOWN...BLOCKING ONE LANE OF BEACON LIGHT RD.

&&

MCAVOY

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
753 PM EDT SUN JUN 23 2013

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0643 PM     TSTM WND DMG     3 SSW COWPENS           34.98N 81.82W
06/23/2013                   SPARTANBURG        SC   FIRE DEPT/RESCUE

            TREE BLOWN DOWN AT CLIFTON GLENDALE RD AND CALVERT ST.

&&

MCAVOY