MESO: Mesoscale Discussion 1699

ACUS11 KWNS 121856
SWOMCD
SPC MCD 121855
OKZ000-TXZ000-122130-

MESOSCALE DISCUSSION 1699
NWS STORM PREDICTION CENTER NORMAN OK
0155 PM CDT MON AUG 12 2013

AREAS AFFECTED...PORTIONS OF THE TX AND OK PANHANDLES AND WRN OK

CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY

VALID 121855Z - 122130Z

PROBABILITY OF WATCH ISSUANCE...5 PERCENT

SUMMARY...AN ISOLATED POTENTIAL FOR A FEW STRONG TO PERHAPS
MARGINALLY SEVERE THUNDERSTORMS CANNOT BE RULED OUT THROUGH THE
REMAINDER OF THIS AFTERNOON INTO THE EARLY EVENING.

DISCUSSION...THE AIR MASS CONTINUES TO DESTABILIZE AS INSOLATION
OCCURS AMIDST SFC DEWPOINTS FROM THE 60S OVER THE TX/OK PANHANDLES
TO THE LOWER 70S IN PARTS OF WRN OK. SFC OBS INDICATE A CONFLUENCE
AXIS EXTENDING FROM NERN NM ENEWD INTO NWRN OK...WHERE IT LINKS WITH
AN OUTFLOW BOUNDARY ARCING FROM S-CNTRL KS INTO CNTRL OK. STORMS
WILL CONTINUE TO INITIATE INVOF THE CONFLUENCE AXIS IN THE TX
PANHANDLE...AND ELSEWHERE ACROSS THE OK/TX PANHANDLES...AS A
LOW-AMPLITUDE SHORTWAVE IMPULSE APPROACHES FROM NM.

ENHANCED MID-LEVEL MOISTURE PRECEDING THE SHORTWAVE IMPULSE WILL
BOLSTER UPDRAFT SHELTERING...WITH ACCOMPANYING ASCENT SERVING TO
MAINTAIN AREAS OF MODERATE INSTABILITY AND LIMIT CONVECTIVE
INHIBITION EVIDENT IN A MODIFIED 12Z AMA RAOB. THIS WILL SUPPORT A
FEW VIGOROUS UPDRAFTS/DOWNDRAFTS WITH STRONG WINDS AND HAIL POSSIBLE
WITH THE MOST INTENSE CORES...AND A MARGINAL SVR THREAT CANNOT BE
RULED OUT. THIS ACTIVITY MAY HAVE A TENDENCY OF BEING STEERED INTO
WRN OK LATER THIS AFTERNOON INTO THE EVENING GIVEN 20-30 KT OF
MID-LEVEL FLOW.

ASSOCIATED DEEP SHEAR WILL ONLY BE MODEST...MID-LEVEL LAPSE RATES
AROUND 6.0-6.5 C/KM WILL LIMIT NORMALIZED CAPE...AND THE
BELOW-1-KM-AGL FLOW AND ACCOMPANYING CONVERGENCE ARE -- AND SHOULD
REMAIN -- RELATIVELY WEAK PER SFC OBS AND VWP DATA. THESE FACTORS
WILL LARGELY MITIGATE THE POTENTIAL FOR MORE SUBSTANTIAL
CONVECTION...AS STORMS EXHIBIT PULSE/OCCASIONAL MULTICELLULAR MODES.

..COHEN/KERR.. 08/12/2013

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

ATTN...WFO...OUN...LUB...AMA...

LAT...LON 36370269 36940116 36659957 35849895 34879976 34530170
34940300 36370269

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