MESO: Mesoscale Discussion 1693

ACUS11 KWNS 222159
SWOMCD
SPC MCD 222159
VAZ000-WVZ000-NCZ000-TNZ000-OHZ000-KYZ000-230000-

MESOSCALE DISCUSSION 1693
NWS STORM PREDICTION CENTER NORMAN OK
0459 PM CDT FRI JUL 22 2011

AREAS AFFECTED...SRN/CNTRL WV...FAR SRN OH...ERN KY...WRN VA...FAR
NWRN NC...FAR NERN TN

CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY

VALID 222159Z - 230000Z

A FEW PULSE STORMS COULD POSE A THREAT FOR DMGG WIND GUSTS INTO THE
LATE AFTERNOON AND EARLY EVENING HOURS. HOWEVER...THE DISORGANIZED
NATURE OF THE CONVECTION WILL LIKELY KEEP THE SVR THREAT ISOLATED
AND PRECLUDE THE ISSUANCE OF A WW.

WITH THE COMBINATION OF PRECONVECTIVE SFC TEMPERATURES IN THE LOWER
90S AND DEWPOINTS IN THE LOWER/MIDDLE 70S...A MODERATELY TO VERY
UNSTABLE AIR MASS HAS DEVELOPED ACROSS PORTIONS OF THE CNTRL/SRN
APPALACHIANS AND OH/TN VALLEY REGION. THE LACK OF MLCINH AND THE
PRESENCE OF OROGRAPHIC FORCING HAVE FOSTERED THE DEVELOPMENT OF
ISOLATED TO WIDELY SCATTERED CONVECTION ACROSS THE DISCUSSION AREA.
THE DEGREE OF INSTABILITY WILL CONTINUE TO SUPPORT VIGOROUS UPDRAFTS
INTO EARLY THIS EVENING. WET MICROBURSTS WILL BE A CONCERN AS STORMS
COLLAPSE...WITH DOWNWARD BUOYANCY ENHANCED BY THE PRESENCE OF STEEP
LOW-LEVEL LAPSE RATES AND WATER LOADING PROCESSES OWING TO PWAT
VALUES OF 1.8 TO 2.2 INCHES PER GPS DATA. DMGG WIND GUSTS MAY OCCUR
ON AN ISOLATED BASIS...THOUGH VWP DATA DEPICT WEAK VERTICAL WIND
SHEAR WHICH WILL MITIGATE THE THREAT FOR ORGANIZED CONVECTION.
LOCALIZED RAINFALL RATES IN EXCESS OF 1 INCH PER HOUR WILL ALSO BE A
THREAT...ESPECIALLY IN AREAS WHERE CONVECTION BECOMES ANCHORED BY
LOCAL TERRAIN EFFECTS. AFTER 00Z...STABILIZATION DUE TO NOCTURNAL
COOLING WILL LIKELY BE ASSOCIATED WITH A WEAKENING TREND IN ONGOING
CONVECTION.

..COHEN.. 07/22/2011

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

ATTN...WFO...RNK...RLX...GSP...MRX...JKL...ILN...

LAT...LON 36078189 36518349 37788395 38808293 39008140 38798041
37997978 37287963 36358028 36078189

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