MESOSCALE DISCUSSION 2198
   NWS STORM PREDICTION CENTER NORMAN OK
   0436 PM CDT MON SEP 01 2008
   
   AREAS AFFECTED...SERN WY...WRN NEB...FAR NERN CO
   
   CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE 
   
   VALID 012136Z - 012300Z
   
   AN ISOLATED SEVERE WIND/HAIL THREAT SHOULD EVOLVE ACORNS THE CNTRL
   HIGH PLAINS THROUGH THIS EVENING AS POTENT SHORT WAVE TROUGH
   APPROACHES REGION. DESPITE WEAK BUOYANCY...STRONG DEEP-LAYER SHEAR
   COUPLED WITH STEEP LOW-LEVEL LAPSE RATES AND BACKGROUND FORCED
   ASCENT MAY BE SUFFICIENT FOR AN ORGANIZED CONVECTIVE CLUSTER. TRENDS
   WILL BE MONITORED FOR THE POSSIBILITY OF A WW ISSUANCE.
   
   TSTMS HAVE RECENTLY COMMENCED ACROSS SERN WY INVOF LAR/CYS. THIS
   DEVELOPMENT APPEARS TO BE TIED TO THE LEADING EDGE OF STRONGLY
   FORCED ASCENT ASSOCIATED WITH VIGOROUS SHORT WAVE TROUGH APPROACHING
   FROM ERN ID/WRN WY. THIS ACTIVITY HAS INTERSECTED A QUASI-STATIONARY
   FRONTAL BOUNDARY RUNNING FROM NRN LARAMIE COUNTY WY TO CHERRY COUNTY
   NEB /PER 21Z SUBJECTIVE SURFACE ANALYSIS/. LOW-LEVEL FLOW HAS VEERED
   TO THE S OF THIS BOUNDARY...INCREASING THE UPSLOPE COMPONENT. THIS
   IN CONJUCTION WITH STRENGTHENING MID-LEVEL FLOW /PER MEDICINE BOW WY
   PROFILER/...WILL RESULT IN STRONG DEEP-LAYER SHEAR. ALTHOUGH MLCAPES
   ARE MEAGER...AOB 500 J/KG...SURFACE DEW POINT DEPRESSIONS AROUND 30
   DEGREES ARE INDICATIVE OF STEEP LOW-LEVEL RATES. THIS WOULD LIKELY
   ENHANCE DOWNDRAFT POTENTIAL AND LEND TO A STRONG/SEVERE WIND
   THREAT...ESPECIALLY IF AN ORGANIZED CONVECTIVE CLUSTER CAN EVOLVE
   EWD ACROSS THE HIGH PLAINS.
   
   ..GRAMS.. 09/01/2008
   
   
   ATTN...WFO...LBF...UNR...GLD...BOU...CYS...
   
   43300163 43030055 42470014 40970131 40310255 40300387
   40560479 40940535 41980474 42870453 43180317