SPC MD 1994

MD 1994 CONCERNING SEVERE POTENTIAL…WATCH POSSIBLE FOR WRN/CENTRAL OK


MESOSCALE DISCUSSION 1994
NWS STORM PREDICTION CENTER NORMAN OK
0717 PM CDT WED SEP 26 2012

AREAS AFFECTED...WRN/CENTRAL OK

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE

VALID 270017Z - 270115Z

PROBABILITY OF WATCH ISSUANCE...40 PERCENT

SUMMARY...POTENTIAL EXISTS FOR TSTM DEVELOPMENT THIS EVENING ACROSS
PARTS OF WRN OK WITH ACTIVITY ADVANCING EWD.  A COMBINATION OF
STORMS MOVING EWD FROM THE SERN TX PANHANDLE INTO ADJACENT OK
COUNTIES...AND NEW DEEP CONVECTION FORMING ALONG A COUPLE OF E-W
ORIENTED BOUNDARIES ALONG AND 35-40 N OF THE I-40 CORRIDOR SHOULD BE
THE PRIMARY FOCUS AREAS.  WHILE TSTM COVERAGE IS EXPECTED TO
INCREASE...A GRADUAL DECREASE IN INSTABILITY...GIVEN TIME OF
DAY...SUGGESTS SOME LIMIT TO THE OVERALL SEVERITY.  THUS...THE
PROBABILITY FOR WATCH ISSUANCE REMAINS AT 40 PERCENT.

DISCUSSION...EARLY EVENING SURFACE ANALYSIS SHOWED A COUPLE OF E-W
ORIENTED BOUNDARIES ACROSS NRN AND WRN OK...1/ EXTENDED WSW FROM
NERN OK TO NORTH OF OKC /30 SE END/ TO THE OK/TX PANHANDLE BORDER
/20 SW GAG/ AND INTO THE NRN TX PANHANDLE...AND 2/ EXTENDED FROM
INVOF OKC WWD GENERALLY ALONG THE I-40 CORRIDOR.  THE AIR MASS
ACROSS MUCH OF OK REMAINS MODERATELY UNSTABLE WITH EFFECTIVE BULK
SHEAR STRONGEST /EXCESS OF 40 KT/ ACROSS NRN OK...THOUGH VALUES
FARTHER SW OF 30-35 KT IN SWRN OK ARE SUFFICIENT FOR STORM
ORGANIZATION.

STORMS DEVELOPING ON THE PERIPHERY OF THE CLOUD SHIELD ATTENDANT TO
THE SERN TX PANHANDLE ACTIVITY AND ANY OF THE TX STORMS THAT MOVE
INTO SWRN OK COULD POSE AT LEAST AN ISOLATED SVR THREAT.  GIVEN THE
EXIT REGION OF AN 80 KT UPPER LEVEL JET WILL SPREAD ACROSS THE TX
PANHANDLE INTO OK THIS EVENING...POTENTIAL...GIVEN THE AVAILABLE
INSTABILITY/SHEAR...WILL EXIST FOR STRONG TO SVR STORMS PRODUCING
STRONG WIND GUSTS AND/OR HAIL.  THE LAST SEVERAL RUNS OF THE
WRF-HRRR PORTRAY THE ONGOING RADAR TRENDS FAIRLY WELL ACROSS THE SRN
PLAINS...WITH NEW STORMS DEVELOPING OVER WEST CENTRAL/SWRN OK
BETWEEN 00-01Z.  THIS GUIDANCE ALSO INDICATED A GRADUAL INCREASE IN
TSTM COVERAGE ACROSS WEST CENTRAL INTO NWRN-NRN OK AS A SHORTWAVE
TROUGH TRACKS FROM SERN CO EWD ALONG THE KS/OK BORDER.

..PETERS/HART.. 09/27/2012

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

ATTN...WFO...OUN...

LAT...LON   36869994 36689717 35539717 34879766 34539870 34589996
            35479998 36869994

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