MESOSCALE DISCUSSION 0871
   NWS STORM PREDICTION CENTER NORMAN OK
   0709 PM CDT SUN MAY 22 2011
   
   AREAS AFFECTED...NWRN LOWER MI
   
   CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE 
   
   VALID 230009Z - 230145Z
   
   A SEVERE THREAT COULD EVOLVE ACROSS NWRN PORTIONS OF LOWER MI THIS
   EVENING. IT IS NOT CLEAR WHETHER A WW IS WARRANTED AT THIS TIME DUE
   TO POTENTIAL LIMITING FACTORS. HOWEVER..AREA WILL CONTINUE TO BE
   MONITORED...AND ANY WW ISSUANCE WILL ULTIMATELY DEPEND ON CONVECTIVE
   TRENDS.
   
   CLUSTER OF STORMS IS CROSSING LAKE MI AND APPROACHING THE COAST OF
   LOWER MI. HOWEVER...DEWPOINTS ARE ONLY IN THE 50S INLAND FROM THE
   COAST...AND MORE SUBSTANTIAL BOUNDARY LAYER MOISTURE RECOVERY HAS
   BEEN LIMITED IN PART BY CONVECTION FARTHER SOUTH. NEVERTHELESS
   OBJECTIVE ANALYSIS SHOW THE ATMOSPHERE TO BE MODERATELY UNSTABLE
   WITH 1000-1500 J/KG MLCAPE. VERTICAL SHEAR IS MODEST...BUT WILL
   LIKELY INCREASE LATER THIS EVENING AS THE UPPER LOW AND LLJ SHIFT
   EWD. WHILE THE LOWER DEWPOINTS AND MODEST SHEAR WILL TEND TO LIMIT
   TORNADO POTENTIAL...HIGH TEMPERATURE-DEWPOINTS SPREADS MAY ENHANCE
   THE THREAT FOR DAMAGING WIND...BUT LOSS OF DIABATIC WARMING COULD
   POTENTIALLY SERVE AS A LIMITING FACTOR.
   
   ..DIAL.. 05/23/2011
   
   
   ATTN...WFO...APX...GRR...
   
   LAT...LON   43738506 43638629 44638603 45548486 45238409 43738506