MESOSCALE DISCUSSION 0333
   NWS STORM PREDICTION CENTER NORMAN OK
   0951 PM CDT SUN APR 03 2011
   
   AREAS AFFECTED...CNTRL/ERN OK...EXTREME SWRN MO AND EXTREME NWRN AR
   
   CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE 
   
   VALID 040251Z - 040415Z
   
   A SEVERE THUNDERSTORM WATCH IS POSSIBLE /30-50% CHANCE/ ACROSS
   PORTIONS OF CNTRL/ERN OK AND FAR SW MO/NW AR LATER THIS EVENING. 
   PRIMARY THREATS WILL BE LARGE HAIL AND DAMAGING WIND GUSTS WITH
   STORMS BACKBUILDING SWWD FROM SERN KS.
   
   WATER VAPOR IMAGERY SUGGESTS THAT 30+ METER HEIGHT FALLS WILL BE
   SPREADING ACROSS CNTRL/NRN OK OVERNIGHT.  THIS MAY BE SUFFICIENT TO
   WEAKEN THE CAP SAMPLED BY 00Z SOUNDINGS OVER OK.  IN FACT...00Z NAM
   AND...TO SOME DEGREE...00Z PARALLEL RAPID REFRESH MODEL BACKBUILD KS
   CONVECTION SWWD ALONG/N OF THE COLD FRONT FROM ROUGHLY I-35 CORRIDOR
   EWD AND N OF I-44 BY 06Z.  THIS ACTIVITY WILL LIKELY CONTINUE SSEWD
   INTO THE 50 KT SLY LLJ AND THETA-E AXIS INTO MUCH OF ERN OK AND SW
   MO/NW AR BY 09Z.  THERE IS A NON-ZERO CHANCE THAT THE WWD EXTENT OF
   STORMS MAY GRAZE PARTS OF THE OKC METRO AREA...BUT MOST LIKELY STAY
   EAST OF I-35 FROM 06-09Z.  
   
   THE STEEP MID-LEVEL LAPSE RATES AND EFFECTIVE SHEAR OF 40 KTS WILL
   BE FAVORABLE FOR LARGE HAIL...ESPECIALLY AS STORMS FIRST FORM. 
   CONVECTIVE MODE SHOULD BE GENERALLY LINEAR...ALTHOUGH THERE MAY BE A
   COUPLE OF DISCRETE ENTITIES THAT MAY EVOLVE WITHIN THE LINE.  CELLS
   THAT CAN DEVELOP AND BE MAINTAINED WITHIN THE FRONTAL ZONE COULD BOW
   AND PRODUCE DAMAGING WINDS.
   
   ..RACY.. 04/04/2011
   
   
   ATTN...WFO...SGF...TSA...ICT...OUN...
   
   LAT...LON   35509714 36119746 36679748 36949725 36989628 37069364
               36239355 35569399 34879517 34919647 35509714