SPC MD 639

MD 0639 CONCERNING TORNADO WATCH 212…214… FOR PORTIONS WRN THROUGH NERN OK…SERN PANHANDLE OF TX…SRN KS…SWRN MO.


MESOSCALE DISCUSSION 0639
NWS STORM PREDICTION CENTER NORMAN OK
0855 PM CDT MON APR 30 2012

AREAS AFFECTED...PORTIONS WRN THROUGH NERN OK...SERN PANHANDLE OF
TX...SRN KS...SWRN MO.

CONCERNING...TORNADO WATCH 212...214...

VALID 010155Z - 010300Z

THE SEVERE WEATHER THREAT FOR TORNADO WATCH 212...214...CONTINUES.

GROWING BAND OF SVR TSTMS FROM SERN TX PANHANDLE EWD ACROSS SWRN OK
WILL BE MOVING EWD INTO FAVORABLE ENVIRONMENT.  AS
SUCH...MULTI-MODAL SVR THREAT SHOULD EXTEND E OF WW 212 ACROSS
PORTIONS SRN/CENTRAL OK DURING REMAINDER EVENING HOURS...AND
EXTENSION OR ADDITIONAL WW MAY BE REQUIRED.  MEANWHILE SVR POTENTIAL
WILL CONTINUE INVOF WARM FRONT OVER NRN OK/SRN KS...WITH A FEW MORE
HOURS OF FULL-SPECTRUM TORNADO/HAIL/WIND THREAT TRANSITIONING MORE
TOWARD WIND LATE THIS EVENING.  GREATEST CORRIDOR OF SVR WIND RISK
STILL APPEARS TO BE INVOF WARM FRONTAL ZONE NEAR KS/OK BORDER.

LOWERING LCL WILL OCCUR WITH SUBTLE DIABATIC SFC COOLING...WHILE
FAVORABLE SFC-BASED BUOYANCY IS MAINTAINED.  PRECONVECTIVE WARM
SECTOR IS AND SHOULD REMAIN CHARACTERIZED OVER OK BY SFC DEW POINTS
COMMONLY MID-UPPER 60S F.  ACCORDINGLY MODIFIED OUN RAOB AND RUC
SOUNDINGS SUGGEST EFFECTIVE INFLOW PARCELS WILL REMAIN SFC-BASED
THROUGH AT LEAST 5Z.  RICH BOUNDARY-LAYER THETAE WILL SUPPORT MLCAPE
OF 2000-3000 J/KG...SIMILAR TO THAT IN OUN RAOB...WHILE LOW-LEVEL
SHEAR STRENGTHENS IN RESPONSE TO STEADILY INCREASING LLJ.  ENLARGED
HODOGRAPHS...SHOULD SUPPORT POTENTIAL FOR SUPERCELLS EMBEDDED WITHIN
EITHER CONVECTIVE CLUSTER...WITH MOST ROBUST TORNADO THREAT
REMAINING INVOF WARM FRONT OVER NRN OK/SRN KS.  EFFECTIVE SHEAR
MAGNITUDES WILL CONTINUE TO BE STRONGER WITH NWD EXTENT TOWARD WW
214 AND WITH WWD EXTENT OVER SRN OK...WITH MAGNITUDES GENERALLY IN
40-50 KT RANGE.

..EDWARDS.. 05/01/2012

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

ATTN...WFO...SGF...TSA...TOP...ICT...OUN...DDC...LUB...AMA...

LAT...LON   34830106 35550047 37899932 38059578 37789409 36469465
            35119607 34269705 34570008 34830106

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