MESOSCALE DISCUSSION 1894
   NWS STORM PREDICTION CENTER NORMAN OK
   1028 PM CDT SUN AUG 07 2011
   
   AREAS AFFECTED...PORTIONS CENTRAL/ERN NEB...WRN IA...EXTREME SERN
   SD.
   
   CONCERNING...SEVERE THUNDERSTORM WATCH 736...741...
   
   VALID 080328Z - 080530Z
   
   THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH
   736...741...CONTINUES.
   
   COUNTIES HAVE BEEN APPENDED TO WW 741 OVER SERN SD AND NERN NEB PER
   COORD W/FSD.  ADDITIONAL WW BAY BE REQUIRED OVER ADJACENT PORTIONS
   IA.  WW 741 MAY BE CLEARED BEHIND BOW AND RELATED OUTFLOW BOUNDARY. 
   MEANWHILE...GIVEN CONVECTIVE/STABILIZATION TRENDS...REMAINDER WW 736
   MAY BE ALLOWED TO EXPIRE OR CANCELED BEFORE SCHEDULED 04Z
   EXPIRATION.
   
   MAIN SVR CONCERN REMAINS BOW ECHO MOVING EWD ABOUT 50 KT ACROSS NRN
   NEB...TOWARD NERN NEB...EXTREME SERN SD AND NWRN IA.  SEVERAL
   MEASURED SVR GUSTS AND REPORTS OF DAMAGING WIND HAVE OCCURRED WITH
   THIS COMPLEX.  WELL-DEVELOPED COLD POOL AND REAR-INFLOW JET HAVE
   BEEN EVIDENT FOR A FEW HOURS...THE LATTER REACHING SFC WITH
   PERSISTENT SVR POSTCONVECTIVE WINDS AT VTN AND ANW.  ACTIVITY IS
   FORWARD-PROPAGATING ALONG THETAE GRADIENT CORRESPONDING TO NRN RIM
   OF RICHER SFC MOISTURE.  ALTHOUGH LOW-LEVEL WINDS ARE RELATIVELY
   WEAK PER REGIONAL VWP/PROFILER/SFC DATA...FAST TRANSLATIONAL SPEED
   OF MCS ENSURES STG STORM-RELATIVE INFLOW.  MEANWHILE...FORCED ASCENT
   ALONG LEADING EDGE OF STG COLD POOL SHOULD CONTINUE TO SUPPORT
   COMPLEX FOR AT LEAST A FEW MORE HOURS...AS IT MOVES THROUGH
   FAVORABLE BUOYANCY.  MODIFIED RAOBS AND FCST SOUNDINGS SUGGEST
   WEAKER MLCINH TO ITS SE...ACROSS E-CENTRAL NEB...AND MCS MAY UNDERGO
   NET ESEWD TURN AS IT APCHS NEB/IA BORDER REGION ACCORDINGLY. 
   EFFECTIVE SFC-BASED PARCELS YIELD MLCAPE 2000-3000 J/KG OVER
   PORTIONS E-CENTRAL NEB AND EXTREME W-CENTRAL IA.  ONLY SLOW
   WEAKENING IN CAPE WITH TIME IS EXPECTED OVER ERN NEB THROUGH SWRN IA
   GIVEN RICHNESS OF LOW-LEVEL MOISTURE...HOWEVER DEW POINTS WILL
   CONTINUE TO BE SOMEWHAT LOWER ACROSS NRN IA.
   
   ..EDWARDS.. 08/08/2011
   
   
   ATTN...WFO...DMX...FSD...OAX...GID...LBF...
   
   LAT...LON   41410018 41569916 42069842 42519823 42809830 43049862
               43059595 42389459 40939487 40649638 40769847 41410018