MESOSCALE DISCUSSION 1512
   NWS STORM PREDICTION CENTER NORMAN OK
   0655 PM CDT THU JUL 23 2015

   AREAS AFFECTED...PORTIONS OF SD/NEB/KS/CO

   CONCERNING...SEVERE THUNDERSTORM WATCH 447...

   VALID 232355Z - 240200Z

   THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 447
   CONTINUES.

   SUMMARY...THE RISK FOR SVR TSTMS CONTINUES IN WW 447.

   DISCUSSION...ISOLATED TSTMS CONTINUE ON THE WARM/MOIST SIDE /EAST TO
   SOUTH/ OF A MIXING BOUNDARY/LEE TROUGH ANALYZED FROM N-CNTRL
   NEB/S-CNTRL SD TO ERN CO. THIS ACTIVITY WILL CONTINUE TO SPREAD
   EWD/SEWD DURING THE NEXT FEW HOURS...AND REMAIN CAPABLE OF SVR
   WIND/HAIL IN A STRONGLY UNSTABLE ENVIRONMENT WITH AROUND 40 KT OF
   DEEP SHEAR SAMPLED BY THE LNX VWP. MOSAIC RADAR AND VIS SATELLITE
   LOOPS SUGGEST THAT THE BOUNDARY IS SLOWLY ADVANCING NWD ACROSS PARTS
   OF NEB/SD...POTENTIALLY REMAINING AN INITIATING BOUNDARY FOR
   CONVECTION IN THE NEXT COUPLE OF HOURS AS RICHER BOUNDARY-LAYER
   MOISTURE OVERSPREADS STEEP LOW-LEVEL LAPSE RATES. WITH WEAK
   LARGE-SCALE ASCENT OVER THE AREA...AND CONVECTION PRIMARILY BEING
   DRIVEN BY DIURNAL HEATING...A GRADUAL WEAKENING TREND IS FORECAST TO
   OCCUR AROUND/AFTER DUSK AS INHIBITION SLOWLY GROWS NOCTURNALLY.

   ..COHEN.. 07/23/2015


   ATTN...WFO...FSD...GID...LBF...UNR...GLD...BOU...

   LAT...LON   38440193 39530227 41800180 43100047 43399886 41699855
               38920061 38440193