MESO: Mesoscale Discussion 1291

ACUS11 KWNS 281905
SWOMCD
SPC MCD 281905
SCZ000-GAZ000-282130-

MESOSCALE DISCUSSION 1291
NWS STORM PREDICTION CENTER NORMAN OK
0205 PM CDT FRI JUN 28 2013

AREAS AFFECTED...PORTIONS OF CNTRL/ERN GA...WRN SC

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE

VALID 281905Z - 282130Z

PROBABILITY OF WATCH ISSUANCE...40 PERCENT

SUMMARY...A POTENTIAL FOR ISOLATED SEVERE THUNDERSTORMS WILL EXIST
THROUGH THE AFTERNOON HOURS...AND THE ISSUANCE OF A SEVERE
THUNDERSTORM WATCH IS POSSIBLE.

DISCUSSION...A WEAK OUTFLOW BOUNDARY ACCOMPANYING MORNING CONVECTION
HAS MOVED INTO NWRN AND W-CNTRL GA AND ARCS WSWWD INTO CNTRL/SRN AL.
THUNDERSTORM DEVELOPMENT HAS BEEN NOTED ACROSS PARTS OF W-CNTRL GA
INVOF THE BOUNDARY AND TO ITS EAST WITHIN A MOIST/LARGELY UNCAPPED
ENVIRONMENT. THIS ACTIVITY MAY HAVE A TENDENCY TO SPREAD EWD/SEWD
ACROSS PARTS OF CNTRL/ERN GA AND INTO WRN SC WHERE MLCAPE VALUES OF
1500-3000 J/KG EXIST OWING TO STRONG DIURNAL HEATING AMIDST A
RELATIVELY MOIST BOUNDARY LAYER. HOWEVER...GPS PW DATA INDICATE A
CORRIDOR OF RELATIVELY LOWER PW EXTENDING FROM THE CNTRL
APPALACHIANS INTO CNTRL GA -- PERHAPS ASSOCIATED WITH A POCKET OF
SUBSIDENT MID-LEVEL FLOW ON THE BACKSIDE OF AN ERN CONUS CYCLONE.
SFC OBS INDICATE DEWPOINTS MIXING OUT INTO THE MIDDLE 60S BENEATH
THIS LOWER-PW CORRIDOR...CONTRIBUTING TO RELATIVELY SMALLER MLCAPE
BUT LARGER SFC TEMPERATURE-DEWPOINT SPREADS. THE NET RESULT MAY BE
FOR ONLY SPORADIC PULSE CONVECTIVE COVERAGE AMIDST WEAK VERTICAL
SHEAR PER VWP DATA...THOUGH ISOLATED DMGG WIND GUSTS WILL BE
POSSIBLE. HOWEVER...SHOULD MULTIPLE COLD POOLS CONGEAL WITH
LOCALIZED AREAS OF UPSCALE CONVECTIVE GROWTH...A GREATER POTENTIAL
FOR DMGG WIND GUSTS MAY ENSUE...POTENTIALLY WARRANTING WW ISSUANCE.
AS SUCH...THE AREA WILL BE MONITORED FOR THE POSSIBLE ISSUANCE OF A
SEVERE THUNDERSTORM WATCH THROUGH THE AFTERNOON.

..COHEN/MEAD.. 06/28/2013

...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...

ATTN...WFO...CHS...CAE...GSP...FFC...

LAT...LON 33058440 34318418 34728277 34198157 33058178 32158273
32018349 32278408 33058440

+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
To unsubscribe from WX-STORM send e-mail to LISTSERV@LISTSERV.ILLINOIS.EDU with
"unsub wx-storm" in the body of your message. For more information write cnovy@cox.net.