MESOSCALE DISCUSSION 0976
   NWS STORM PREDICTION CENTER NORMAN OK
   0646 PM CDT THU MAY 22 2008
   
   AREAS AFFECTED...NEB...KS...OK...TX
   
   CONCERNING...TORNADO WATCH 335...336...337...
   
   VALID 222346Z - 230045Z
   
   THE SEVERE WEATHER THREAT FOR TORNADO WATCH
   335...336...337...CONTINUES.
   
   LATE AFTERNOON/EARLY EVENING SURFACE ANALYSIS SHOWED AN AREA OF LOW
   PRESSURE LOCATED OVER NORTH CENTRAL CO WITH A WARM FRONT EXTENDING
   ESEWD ACROSS NWRN KS THROUGH NRN KS TO CENTRAL MO.  DRY LINE...AIDED
   BY STRONG SSWLY GRADIENT WINDS...HAD SHIFTED EWD INTO NERN CO AT
   INTERSECTION WITH WARM FRONT AND THEN EXTENDED SWD THROUGH WRN KS TO
   THE ERN TX PANHANDLE. 
   
   ...WW/S 335 AND 337...
   MOIST/MODERATELY UNSTABLE WARM SECTOR COMBINED WITH 40-60 KT OF SWLY
   EFFECTIVE BULK SHEAR VECTORS REMAINS CONDUCIVE FOR TORNADIC
   SUPERCELLS THROUGH THE EARLY EVENING.  LATEST OBJECTIVE ANALYSES
   INDICATED VERY STRONG EFFECTIVE SRH VALUES /300-600 M2/S2/ EXTENDING
   FROM NWRN KS THROUGH SWRN NEB TO NERN CO...ALONG NOSE OF 40 KT SSELY
   LLJ...AND BACKED LOWER LEVEL WINDS IN VICINITY OF THE WARM FRONT. 
   THIS WILL SUPPORT A CONTINUED TORNADO THREAT ACROSS MUCH OF WW 335
   AND 337...INCLUDING THOSE REGIONS JUST N OF THE WARM FRONT WHERE
   EFFECTIVE PARCELS REMAIN SURFACE BASED.
   
   ...WW 336...
   ASCENT ATTENDANT TO SRN EXTENT OF SHORT WAVE TROUGH...NOW CENTERED
   OVER THE CENTRAL HIGH PLAINS OF NERN CO/WRN NEB...WILL CONTINUE TO
   SUPPORT TSTM DEVELOPMENT ALONG THE SRN EXTENT OF THE DRY LINE. 
   MODERATE-STRONG INSTABILITY COMBINED WITH EFFECTIVE BULK SHEAR OF
   40-50 KT AND EFFECTIVE SRH VALUES OF 100-200 M2/S2 REMAIN VERY
   FAVORABLE FOR TORNADIC SUPERCELLS ACROSS FAR ERN TX PANHANDLE INTO
   WRN OK.  PARTICULAR CONCERN EXISTS WITH THE DEVIANT MOVING /EWD
   STORM MOTION/ OF THE SUPERCELL NOW LOCATED OVER ROGER MILLS COUNTY
   WHERE PARAMETERS ARE VERY FAVORABLE FOR TORNADOES.
   
   FARTHER S OF THE ROGER MILLS SUPERCELL...WEAKER ASCENT WITH SWD
   EXTENT ALONG VORTICITY LOBE APPEARS TO BE LIMITING CONVECTIVE
   DEVELOPMENT INTO NW TX AT THIS TIME.  IF THIS TREND CONTINUES...SRN
   PARTS OF WW 336 MAY BE CANCELLED PRIOR TO WATCH EXPIRATION OF 03Z.
   
   ..PETERS.. 05/22/2008
   
   
   ATTN...WFO...ICT...OUN...GID...LBF...DDC...GLD...LUB...AMA...PUB...BOU...
   
   41020019 41059870 39109852 38749899 38209850 36989827
   36149809 33479801 33400054 34480099 37750115 38290207
   40390204 41390210 41370026