MESOSCALE DISCUSSION 1713
   NWS STORM PREDICTION CENTER NORMAN OK
   0433 PM CDT FRI AUG 10 2007
   
   AREAS AFFECTED...WRN/CENTRAL SD AND NRN NEB
   
   CONCERNING...SEVERE POTENTIAL...WATCH LIKELY 
   
   VALID 102133Z - 102230Z
   
   THUNDERSTORM DEVELOPMENT APPEARS LIKELY THE NEXT 1-2 HOURS FROM WRN
   SD INTO NRN NEB.  A SEVERE TSTM WATCH MAY BE NEEDED SOON.
   
   VISIBLE IMAGERY SHOWS DEEPENING CUMULUS DEVELOPMENT INVOF A SURFACE
   TROUGH ACROSS WRN SD...WITH SEPARATE CUMULUS DEVELOPMENT ALONG AN
   OUTFLOW BOUNDARY IN NRN NEB.  RICHER MOISTURE AND RESULTANT STRONG
   INSTABILITY IS PRESENT ALONG THE OUTFLOW BOUNDARY IN NEB...EXTENDING
   NWD INTO SRN/CENTRAL SD.  TO THE W...HOT SURFACE TEMPERATURES AND A
   DEEP MIXED LAYER HAVE REDUCED CONVECTIVE INHIBITION TO THE POINT
   THAT THUNDERSTORM DEVELOPMENT NOW APPEARS LIKELY BY 22-23Z.  VERY
   STEEP LAPSE RATES AND EFFECTIVE BULK SHEAR OF 40-50 KT SHOULD
   SUPPORT A FEW SUPERCELL TYPE STORMS...WITH LARGE HAIL AND DAMAGING
   WINDS THE MAIN SEVERE THREATS THROUGH THE EVENING.
   
   ..THOMPSON.. 08/10/2007
   
   
   ATTN...WFO...ABR...LBF...UNR...
   
   44900150 44840064 44540034 43430027 42099934 41789993
   41820157 42270207 42740222 44710164