MESOSCALE DISCUSSION 1700
   NWS STORM PREDICTION CENTER NORMAN OK
   0332 PM CDT THU AUG 09 2007
   
   AREAS AFFECTED...NRN NEB AND SRN SD
   
   CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE 
   
   VALID 092032Z - 092300Z
   
   STORMS ARE EXPECTED TO DEVELOP THROUGH THE LATE AFTERNOON HOURS INTO
   THE EVENING...WITH LARGE HAIL AND DAMAGING WINDS.
   
   SURFACE ANALYSIS SHOWS LOW PRESSURE TROUGH DEVELOPING FROM SERN MT
   ACROSS NWRN SD SWD INTO NWRN NEB WHERE STRONG HEATING HAS ERASED
   MOST CONVECTIVE INHIBITION. VISIBLE IMAGERY CONFIRMS CAPPING HAS
   ERODED WITH HIGH BASED CU FIELDS INCREASING ACROSS NWRN NEB/SWRN SD.
   SURFACE WINDS ARE CURRENTLY LIGHT MOST AREAS BUT BEGINNING TO
   INCREASE ACROSS SWRN NEB INDICATIVE OF LLJ. MEANWHILE...A MORE
   MOIST/UNSTABLE BUT SLIGHTLY CAPPED AIR MASS RESIDES ACROSS SERN
   SD/NERN NEB WITH BACKED SFC WINDS.
   
   HIGH BASED CONVECTION BETWEEN CDR AND VTN WILL LIKELY EVOLVE INTO
   ONE OR MORE SEVERE STORMS. INITIALLY HIGH BASED...THE THREAT WILL BE
   MAINLY GUSTY WINDS. AS THESE STORMS MOVE EWD...THEY WILL ENCOUNTER
   AN INCREASINGLY MOIST AND UNSTABLE AIR MASS. GIVEN FAVORABLE WIND
   PROFILES IN PLACE FOR SUPERCELLS...THE STORMS WILL LIKELY INCREASE
   IN INTENSITY WITH A VERY LARGE HAIL AND DAMAGING WIND THREAT. HIGH
   BASES AND WEAK LOW LEVEL SHEAR INITIALLY WILL PRECLUDE ANY TORNADO
   THREAT. HOWEVER...AS LOW LEVEL JET INCREASES AFTER 00Z...SO WILL LOW
   LEVEL SHEAR AND MOISTURE...WHICH WILL PROVIDE A MORE FAVORABLE
   ENVIRONMENT FOR AN ISOLATED TORNADO IF STORM MODE REMAINS DISCRETE.
   
   ..JEWELL.. 08/09/2007
   
   
   ATTN...WFO...FSD...OAX...ABR...LBF...UNR...CYS...
   
   42049924 41790114 41960234 42520309 43410237 43950134
   43999894 43599799 42879766 42349788