MESO: Mesoscale Discussion 1761

ACUS11 KWNS 231715
SWOMCD
SPC MCD 231714
NCZ000-VAZ000-231945-

MESOSCALE DISCUSSION 1761
NWS STORM PREDICTION CENTER NORMAN OK
1214 PM CDT FRI AUG 23 2013

AREAS AFFECTED...SCNTRL THROUGH SERN VA AND NRN NC

CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY

VALID 231714Z - 231945Z

PROBABILITY OF WATCH ISSUANCE...20 PERCENT

SUMMARY...A FEW STORMS WILL BECOME CAPABLE OF PRODUCING ISOLATED
STRONG TO DAMAGING WING GUSTS THIS AFTERNOON FROM SCNTRL AND SERN VA
INTO NC. OVERALL THREAT APPEARS MARGINAL...AND COVERAGE OF ANY
SEVERE EVENTS IS NOT EXPECTED TO BE SUFFICIENT FOR A WW.

DISCUSSION...EARLY THIS AFTERNOON A WEAK AND SLOW MOVING COLD FRONT
EXTENDS FROM SRN VA WWD THROUGH ERN AND SRN KY. THE N-S THETA-E
GRADIENT ALONG THIS FRONT IS WEAK WITH THE BOUNDARY MANIFESTED
PRIMARILY BY A WIND SHIFT AND SLIGHT DECREASE IN TEMPERATURE. STORMS
ARE CURRENTLY DEVELOPING OVER CNTRL VA NORTH OF THE FRONT IN
ASSOCIATION WITH FORCING FOR ASCENT ASSOCIATED WITH AN EWD MOVING
VORTICITY MAXIMUM. DESPITE THE POST FRONTAL NATURE OF THE
CONVECTION...SFC DEWPOINTS AROUND 70 EXIST IN THIS REGION AND STORMS
ARE LIKELY SFC BASED AS TEMPERATURES RISE INTO THE LOW 80S
CONTRIBUTING TO 1000-1500 J/KG MLCAPE. WHILE THE WEAK MID-LEVEL
LAPSE RATES AND WIDESPREAD CLOUDS WILL PROVIDE A LIMITING FACTOR FOR
A MORE ROBUST SEVERE THREAT...A BELT OF 25-30 KT FLOW WITHIN THE
BASE OF THE SHORTWAVE TROUGH ABOVE LIGHT ELY-NELY WINDS IN THE POST
FRONTAL REGIME IS SUPPORTING 30-35 KT EFFECTIVE SHEAR. THIS
ENVIRONMENT WILL PROMOTE A FEW PERSISTENT MULTICELLS AND UPDRAFTS
WITH MODEST MID-LEVEL ROTATION CAPABLE OF MAINLY ISOLATED STRONG TO
DAMAGING WIND GUSTS AS LOW-LEVEL LAPSE RATES STEEPEN.

FARTHER SOUTH...ONLY A WEAK CAP IS IN PLACE ACROSS NC...AND STORMS
WILL LIKELY DEVELOP AND SPREAD EWD OFF THE HIGHER TERRAIN WITH
INITIATION ALSO LIKELY IN WARM SECTOR. WEAKER SHEAR IN THIS REGION
WILL PROMOTE MULTICELLS...BUT STRONGER DIABATIC WARMING OF THE
BOUNDARY LAYER SUGGEST A FEW STORMS COULD POSE A THREAT FOR ISOLATED
STRONG TO DAMAGING WIND GUSTS.

..DIAL/THOMPSON.. 08/23/2013

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

ATTN...WFO...AKQ...MHX...LWX...RAH...RNK...GSP...

LAT...LON 35347819 35248187 35848186 36697938 37887877 37667749
37577633 36527616 35347819

+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
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.