MESOSCALE DISCUSSION 1418
   NWS STORM PREDICTION CENTER NORMAN OK
   0221 PM CDT SUN JUL 08 2007
   
   AREAS AFFECTED...ERN UPPER MI PENINSULA AND NRN LOWER MI
   
   CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE 
   
   VALID 081921Z - 082045Z
   
   ...AN ISOLATED SEVERE STORM OR TWO IS POSSIBLE ACROSS THE AREA FOR
   THE NEXT FEW HOURS...BUT GREATER THREAT FOR SEVERE STORMS IS NOT
   EXPECTED UNTIL EARLY EVENING. A WW WOULD BE POSSIBLE AT THAT TIME. 
   
   AT 19Z...AN UPPER LEVEL SHORTWAVE WAS LOCATED OVER LAKE HURON....
   ABOUT 50 E OF APN...AND WAS HEADING SEWD. ANOTHER SHORTWAVE TROUGH
   WAS MOVING EWD THROUGH ERN SD...RESULTING IN WEAK SHORTWAVE RIDGING
   OVER MI ATTM. THIS SHOULD MINIMIZE THE CONVECTIVE THREAT SOMEWHAT
   FOR THE NEXT FEW HOURS...THOUGH VEERING WIND PROFILES AND VERY STEEP
   LAPSE RATES WOULD BE SUPPORTED OF ISOLATED ELEVATED STORMS
   THROUGHOUT THE AFTERNOON.
   
   HOWEVER...STORMS ARE EXPECTED TO INCREASE IN COVERAGE AND INTENSITY
   BY EARLY EVENING AS A COLD FRONT...IN FAR WRN UPPER MI ...MOVES SEWD
   INTO THE AREA ALONG WITH THE APPROACHING UPPER LEVEL WAVE. THESE
   SURFACE BASED STORMS SHOULD BE ABLE TO TAP INTO THE MODERATE
   BOUNDARY LAYER INSTABILITY AND 40-50 KT DEEP LAYER SHEAR...WHICH
   WOULD THEN BE FAVORABLE FOR SUPERCELLS WITH HAIL AND DAMAGING WINDS.
   
   ..IMY.. 07/08/2007
   
   
   ATTN...WFO...DTX...APX...GRR...MQT...
   
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