MESOSCALE DISCUSSION 0834
   NWS STORM PREDICTION CENTER NORMAN OK
   1251 PM CDT SAT MAY 21 2011
   
   AREAS AFFECTED...ERN NEB...SERN SD...WRN IA...SWRN MN
   
   CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE 
   
   VALID 211751Z - 211945Z
   
   ISOLATED TO SCATTERED THUNDERSTORMS ARE EXPECTED TO FORM OVER THE
   NEXT 1-2 HOURS WITH MAINLY A LARGE HAIL THREAT INITIALLY.
   
   SURFACE ANALYSIS SHOWS AN AXIS OF MOISTURE AND INSTABILITY ALONG THE
   MO RIVER WITH DEWPOINTS INTO THE LOWER 60S F. THE 12Z OAX SOUNDING
   INDICATED STEEP LAPSE RATES ALOFT...WITH NEARLY 2000 J/KG MUCAPE
   WHEN MODIFIED FOR CURRENT SURFACE OBSERVATIONS. WITH CONTINUED
   HEATING...LITTLE CONVECTIVE INHIBITION WILL EXIST.
   
   MEANWHILE...A DISTURBANCE ROTATING AROUND THE UPPER LOW HAS RESULTED
   IN AN AREA OF SHOWERS PRODUCING OUTFLOW OVER CNTRL NEB.
   RECENTLY...SURFACE BASED CU HAVE BEGUN TO DEVELOP ALONG THE LEADING
   EDGE. THIS MAY INSTIGATE STORM FORMATION. ANOTHER AREA OF POSSIBLE
   INITIATION WILL BE ALONG THE NWD RETURN OF MORE ROBUST LOW LEVEL
   MOISTURE...CURRENTLY EXTENDING FROM NEAR LNK SWWD TOWARD HYS.
   
   WITH TIME...WIND PROFILES WILL BECOME MORE FAVORABLE FOR ORGANIZED
   SEVERE CONVECTION...INCLUDING SUPERCELLS BY LATE AFTERNOON/EARLY
   EVENING. WHILE HAIL WILL BE THE INITIAL THREAT...A TORNADO THREAT
   MAY DEVELOP LATER.
   
   ..JEWELL.. 05/21/2011
   
   
   ATTN...WFO...MPX...DMX...EAX...FSD...OAX...GID...
   
   LAT...LON   40989436 40439491 40089573 40049662 40049743 40139779
               40409778 41109708 41759694 42569713 43229772 43629759
               43929648 43809522 43169419 42319388 41639400 41479400
               40989436