MESO: Mesoscale Discussion 2349

ACUS11 KWNS 212146
SWOMCD
SPC MCD 212146
TXZ000-212345-

MESOSCALE DISCUSSION 2349
NWS STORM PREDICTION CENTER NORMAN OK
0346 PM CST MON NOV 21 2011

AREAS AFFECTED...CNTRL INTO NERN TX

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE

VALID 212146Z - 212345Z

THE THREAT FOR SVR THUNDERSTORMS COULD INCREASE DURING THE NEXT FEW
HOURS FROM CNTRL INTO NERN TX...AND THIS AREA WILL BE MONITORED FOR
THE POSSIBLE ISSUANCE OF A WW.

VISIBLE SATELLITE IMAGERY AND SFC OBS INDICATE A STRONG FRONT SLOWLY
RETREATING NWD OVER PORTIONS OF CNTRL/ERN TX...WITH MLCAPE VALUES OF
1000-1500 J/KG SOUTH OF THE BOUNDARY. THIS IS OCCURRING AS
INCREASING MID-LEVEL HEIGHT FALLS AHEAD OF A PAIR OF APPROACHING
SHORTWAVE TROUGHS INDUCE SFC PRESSURE FALLS OF 3 TO 4 MB PER 2 HRS
NORTH OF THE BOUNDARY. LITTLE IN THE WAY OF CONVECTION HAS BEEN
NOTED NEAR OR SOUTH OF THE BOUNDARY THUS FAR...OWING TO WEAK
VELOCITY CONVERGENCE ALONG THE FRONT...WITH THE STRONGEST DEEP-LAYER
ASCENT AND ASSOCIATED CONVECTION FARTHER N ACROSS N-CNTRL TX NWD
INTO OK. HOWEVER...AS THE MID-LEVEL TROUGHS MAKE ADDITIONAL EWD
PROGRESS...THUNDERSTORMS COULD DEVELOP LATER THIS AFTERNOON.
EFFECTIVE BULK SHEAR MAGNITUDES OF 50-55 KT WILL CONDITIONALLY
PROMOTE A THREAT FOR SUPERCELLS...WITH SVR HAIL THE PRIMARY CONCERN.
HOWEVER...ANY STORMS THAT ARE ABLE TO INTERACT WITH THE FRONT AS IT
LIFTS NWD...OR EVOLVE WITHIN THE WARM SECTOR...WILL ALSO BE CAPABLE
OF PRODUCING DMGG WIND GUSTS...AND POSSIBLY A TORNADO.
HOWEVER...WEAKENING LOW-LEVEL SRH WITH SWD DISPLACEMENT FROM THE
BOUNDARY PER VWP DATA SUGGESTS THAT ANY TORNADO THREAT...ALBEIT
MINIMAL...WILL BE CONFINED TO A NARROW CORRIDOR ALONG THE SFC FRONT.
GIVEN THE UNCERTAINTY IN CONVECTIVE INITIATION/COVERAGE...THE NEED
FOR A WW IS UNCERTAIN. HOWEVER...TRENDS WILL CONTINUE TO BE
MONITORED FOR POTENTIAL WW ISSUANCE.

..COHEN.. 11/21/2011

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

ATTN...WFO...SHV...HGX...FWD...EWX...

LAT...LON 32549426 31779511 30729647 30499754 31249806 32399779
33139713 33549631 33699554 33679486 33239424 32549426

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