Severe Thunderstorm Warning 122, NWS Greenville-Spartanburg, SC

026 
WWUS52 KGSP 090023
SVSGSP

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
823 PM EDT SUN MAY 8 2011

SCC045-059-083-090045-
/O.CON.KGSP.SV.W.0122.000000T0000Z-110509T0045Z/
LAURENS SC-SPARTANBURG SC-GREENVILLE SC-
823 PM EDT SUN MAY 8 2011

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 845 PM EDT
FOR EAST CENTRAL GREENVILLE...SOUTHWESTERN SPARTANBURG AND NORTH
CENTRAL LAURENS COUNTIES...

AT 816 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO
INDICATE A SEVERE THUNDERSTORM.  THIS STORM WAS LOCATED NEAR
TAYLORS...OR NEAR DOWNTOWN GREENVILLE...MOVING SOUTHEAST AT 20 MPH.

OTHER LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO HAYWOOD
MALL...GSP AIRPORT...PELHAM ROAD AT I-85...SHOPS AT GREENRIDGE...FIVE
FORKS...WOODRUFF...REIDVILLE...ORA...GRAY COURT...FOUNTAIN 
INN...ENOREE AND CROSS ANCHOR.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

THIS STORM MAY PRODUCE WIND GUSTS TO 60 MPH AND QUARTER SIZED HAIL. 
ALSO...THIS STORM MAY CAUSE FLOODING OF ROADS WITH POOR 
DRAINAGE...PARTICULARLY IN URBAN AREAS. DO NOT DRIVE YOUR VEHICLE 
INTO AREAS WHERE WATER COVERS THE ROAD. THE WATER MAY BE TOO DEEP TO 
ALLOW YOUR VEHICLE TO CROSS.

&&

LAT...LON 3491 8241 3499 8227 3468 8183 3460 8185
      3448 8200
TIME...MOT...LOC 0022Z 318DEG 16KT 3487 8233

$$
LG

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
736 PM EDT SUN MAY 8 2011

.SYNOPSIS...
AN UPPER RIDGE WILL CONTINUE STRENGTHEN ACROSS THE EASTERN HALF OF
THE COUNTRY THROUGH TUESDAY. THIS RIDGE WILL THEN SLOWLY BEGIN TO
WEAKEN LATE IN THE WEEK AS A CLOSED UPPER LOW APPROACHES FROM THE
WEST FOR THE WEEKEND.

&&

.NEAR TERM /THROUGH MONDAY/...
2300 UTC UPDATE...ISOLATED SHOWERS HAVE DEVELOPED ALONG THE BACK
DOOR COLD FRONT IN UPSTATE SC...NOT TOO FAR FROM INTERSTATE 26...AND
POPS AND SKY COVER WILL BE RAISED IN THAT AREA EARLY THIS EVENING.
SKY COVER WILL BE LOWERED TO THE NORTH. FOG HAS BEEN ADDED LATE
TONIGHT IN AREAS WHERE GUIDANCE LEND THE GREATEST SUPPORT... MAINLY
IN MOUNTAIN VALLEYS...AND THE INTERSTATE 40 CORRIDOR.

PREVIOUS DISCUSSION...WEAK SFC BOUNDARY/BACK DOOR COLD FRONT WILL
CONTINUE TO SINK SLOWLY S THRU THE AREA THIS AFTN-EVE. MODEL
SOUNDINGS SHOW NE CWA LESS UNSTABLE SO WENT WITH SLIGHT CHC POPS NE
OF I-26 AND CHC ALONG AND W. CAPE INCREASES TO AROUND 1000
J/KG...MAINLY SE CWA AND WITH CONVERGENCE ALONG THE WEAK FRONT A
COUPLE STRONG STORMS WILL BE PSBL. MOST CONVECTION THAT DOES FIRE
WILL TAPER OFF BY SS BUT SOME CONVECTION COULD LINGER OVER THE
SAVANNAH VLY TIL LATE EVE. NAM SHOWS LOW LVL MOISTURE AROUND 925MB
MOVG IN FROM THE NE MON MRNG...DID NOT GO FOR MCLDY SKIES YET BUT
INCRSD CLOUD COVER TIL MID MRNG. IF IT OCCURS IT SHOULD BURN OFF BY
MID-LATE MRNG. THEN EXPECT INCREASING CLOUDS IN THE AFTN WITH A
SLIGHT CHC OF SHWRS/TSTMS OVER THE MTNS INTO THE NC N FOOTHILLS.
TEMPS WILL BE ABOVE AVG.

&&

.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY/...
AS OF 230 PM SUNDAY...STARTING MONDAY EVENING...THE NEARLY
STATIONARY FRONT SHOULD BE FROM TN ACROSS GA.  AS IMPULSES TRACK
SOUTHEAST FROM KY ALONG THE BOUNDARY INTO MID WEEK...SHOWERS AND
THUNDERSTORMS WILL BE ON THE INCREASE.  THE MAIN IMPULSE WILL ARRIVE
LATE TUESDAY INTO TUESDAY EVENING...TIMING A LITTLE DIFFERENT
BETWEEN NAM...SREF...GFS AND ECMWF.  THE NAM SEEMS A LITTLE FASTER
BRINGING IT IN TUESDAY AFTERNOON WHILE THE OTHER MODELS HOLD OFF
UNTIL THE EVENING.  AS THE FRONT DRIFTS A BIT INTO THE WESTERN
CAROLINAS AND THE LOW AND MID LEVEL FLOW GOES MORE TOWARD A NNW TO
SSE DIRECTION...MOST OF THE ACTIVITY WILL CROSS THE WRN CAROLINAS
WITH LESS OVER NE GA.  WITH THE ARRIVAL OF THE THE SHORTWAVE...700MB
FLOW REACHES 30 TO 40 KTS.  LATE TUES AFTERNOON CAPES WILL BE OVER
1000 FOR PARTS OF NE GA AND UPSTATE.  THE BULK OF THE RAIN WILL
DECREASE AND MOVE SE WED MORNING BUT SOME REFIRE OF CONVECTION WED
AFTERNOON WITH HEATING...BUT MOSTLY OVER THE MTNS.  A FEW SEVERE
STORMS COULD OCCUR LATE TUESDAY AND PERHAPS A COUPLE WED.
TEMPERATURES WILL BE A FEW DEGREES ABOVE NORMAL FOR THE WRN MTNS
DOWN ACROSS NE GA AND UPSTATE. NOT QUITE AS WARM FOR NC PIEDMONT AS
WOULD BE GOING INTO TROUGH AND SOME INFLUENCE OF A WEAK CAD ON WED.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
AS OF 130 PM SUNDAY...THE MEDIUM RANGE WILL FEATURE A RATHER
SIGNIFICANT PATTERN CHANGE AS A CLOSED UPPER LOW IS EXPECTED TO
BREAKDOWN THE PROMINENT EASTERN CONUS RIDGE THROUGH THE WEEKEND. I
HAVE GENERALLY FAVORED THE 00Z ECMWF AND HPC GUIDANCE FOR THE
DETAILS OF THE FORECAST. REGARDLESS...OVERALL CONFIDENCE IS LOW WITH
SUCH A SIGNIFICANT AND COMPLEX PATTERN CHANGE PROGGED BY THE MEDIUM
RANGE MODELS. THE PERIOD BEGINS WEDNESDAY NIGHT WITH THE RIDGE AXIS
POSITIONED JUST WEST OF THE FA AND THE DEVELOPING UPPER LOW MOVING
INTO THE PLAINS. THE UPPER LOW IS EXPECTED TO GRADUALLY MAKE
EASTWARD PROGRESS INTO THE WEEKEND AS THE RIDGE CONTINUES TO WEAKEN.
BY FRIDAY NIGHT...SOME UPPER DIFFLUENCE ON THE EASTERN PERIPHERY OF
THE CLOSED LOW WILL BEGIN TO MOVE OVER THE REGION AND THIS CONTINUES
THROUGHOUT THE WEEKEND. AS THIS OCCURS...FLOW WILL BECOME MORE
SOUTHERLY OVER AN INCREASINGLY DEEPER LAYER AND DEEP MOISTURE WILL
RAMP UP. AT THE SURFACE...A LOW PRESSURE SYSTEM ASSOCIATED WITH THE
UPPER LOW WILL SLOWLY PUSH EASTWARD AS WELL. THEREFORE...POPS ON
THURSDAY AND FRIDAY WILL LARGELY BE CONTROLLED BY DIURNAL HEATING.
BY SATURDAY AND SUNDAY...POPS WILL BE MORE DETERMINED BY THE
PRESENCE AND STRENGTH OF DEEP FORCING WITH THE UPPER LOW AND THE
INCREASINGLY MOIST ATMOSPHERE. THE PRESENCE OF DEEPENING SOUTHERLY
UPSLOPE FLOW WILL LIKELY FAVOR THE MOUNTAINS AND THE ESCARPMENT
AREAS FOR THE BEST POP OVER THE WEEKEND. TEMPS WILL START OUT ABOUT
5 DEGREES ABOVE CLIMO FOR THURSDAY AND FRIDAY...COOLING TO NEAR
NORMAL OVER THE WEEKEND UNDER FALLING HEIGHT FROM THE APPROACHING
UPPER LOW AND EXPECTED CONSIDERABLE CLOUDINESS.

&&

.AVIATION /00Z MONDAY THROUGH FRIDAY/...
AT KCLT...FEW ARE CLOUDS APPARENT IN SATELLITE IMAGERY...AND
GUIDANCE GENERALLY KEEPS IT THAT WAY. NNE WINDS ARE EXPECTED ON THE
NORTH SIDE OF A BACK DOOR COLD FRONT. LAV GUIDANCE SUPPORTS A BRIEF
FOG RESTRICTION AT DAYBREAK...WHILE THE MAV AND MET DO NOT. FOR NO A
LOW VFR VSBY WILL BE CARRIED WITH FOG AT DAWN. CONVECTION MONDAY
AFTERNOON SHOULD BE FAR ENOUGH SOUTHWEST OF KCLT...NEARER THE
FRONT...TO PRECLUDE A MENTION OF CUMULONIMBUS IN THE TAF.

ELSEWHERE...CLOUDS WILL REMAIN FOCUSED ALONG A WEAK BACK DOOR COLD
FRONT SINKING SLOWLY S ACROSS UPSTATE SC AND THE NC MOUNTAINS.
CHANCES OF CONVECTION WILL REMAIN RATHER LIMITED...AND ONLY KGMU AND
KGSP WILL RECEIVE A TEMPO FOR THUNDER...WITH CUMULONIMBUS WILL BE
MENTIONED IN THE OTHER TAFS...EXCEPT AT KHKY WHICH WILL BE TOO FAR
NORTH OF THE FRONT. SW WINDS TO THE SOUTH OF THE FRONT WILL VEER TO
NNE AS IT MOVES SOUTH. CONVECTION TAPERS OFF LATE THIS EVENING.
GUIDANCE IS MIXED ON SUPPORT FOR FOG RESTRICTIONS AT DAYBREAK...BUT
EVEN THE MOST PESSIMISTIC SOLUTION ONLY GOES MVFR AT KAVL...AND LOW
VFR AT THE OTHER AIR FIELDS. GUIDANCE WINDS SUGGEST THE FRONT WILL
RETURN NORTH IN UPSTATE SC IN THE AFTERNOON. AFTERNOON CONVECTION ON
MONDAY WILL BE GREATEST NEAR THE FRONT...BUT WITH CONFIDENCE
LOW...CUMULONIMBUS WILL NOT INCLUDED IN THE TAFS.

OUTLOOK...A WEAK FRONT WILL REMAIN OVER THE REGION THRU MID WEEK
WITH A CHANCE OF SHWRS/TSTMS OVER THE AREA. PATCHY FOG WILL BE PSBL
EACH MRNG WITH THE HIGHER RH.

&&

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

&&

SYNOPSIS...BSH
NEAR TERM...JAT/RB
SHORT TERM...DEO
LONG TERM...BSH
AVIATION...JAT

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
555 PM EDT SUN MAY 8 2011

GAZ010-017-018-026-028-029-NCZ033-035>037-048>053-056>059-062>065-
068>072-082-501>510-SCZ001>014-019-092200-
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-
555 PM EDT SUN MAY 8 2011

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

.DAY ONE...TONIGHT.

ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS WILL DEVELOP THIS
EVENING. THE GREATEST CHANCE FOR THUNDERSTORMS WILL EXIST IN THE
UPPER SAVANNAH RIVER VALLEY. SOME OF THESE STORMS WILL BECOME
STRONG WITH PERHAPS A FEW REACHING SEVERE LEVELS. THE MAIN THREAT
WITH THE STRONGEST STORMS WILL BE DAMAGING WINDS. LARGE HAIL IS
ALSO POSSIBLE.

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

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.SPOTTER INFORMATION STATEMENT...

NONE.

07

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
709 PM EDT SUN MAY 8 2011

SCZ006-007-012-013-082345-
GREATER GREENVILLE-LAURENS-SPARTANBURG-UNION-
709 PM EDT SUN MAY 8 2011

...A THUNDERSTORM WAS DEVELOPING JUST SOUTHEAST OF THE
GREENVILLE-SPARTANBURG AIRPORT AND WILL AFFECT EASTERN GREENVILLE
...NORTHEASTERN LAURENS...SOUTHERN SPARTANBURG AND WESTERN
UNION COUNTIES THROUGH 745 PM EDT...

CLOUD TO GROUND LIGHTNING AND WIND GUSTS OF 30 TO 40 MPH ARE
EXPECTED WITH THIS STORM AS IT MOVES SOUTHEAST AT 20 MPH.

LAT...LON 3463 8159 3441 8178 3478 8230 3490 8218

LG