MESOSCALE DISCUSSION 0771
   NWS STORM PREDICTION CENTER NORMAN OK
   0511 AM CDT THU MAY 20 2004
   
   AREAS AFFECTED...WRN
   
   CONCERNING...SEVERE THUNDERSTORM POTENTIAL 
   
   VALID 201011Z - 201215Z
   
   STORMS MOVING EWD THROUGH LAKE MI MAY POSE A THREAT FOR HAIL AND A
   CONDITIONAL THREAT FOR ISOLATED STRONG WIND GUSTS ACROSS SRN HALF OF
   LOWER MI NEXT COUPLE HOURS. AREA WILL CONTINUE TO BE MONITORED.
   
   EARLY THIS MORNING AN MCS IS MOVING EWD THROUGH S CNTRL LAKE MI AT
   AROUND 45 KT. THESE STORMS ARE BEING SUPPORTED BY WARM ADVECTION AND
   FEED OF HIGH THETA-E AIR ACCOMPANYING THE NRN BRANCH SWLY LOW LEVEL
   JET. ORIENTATION OF THE LOW LEVEL JET WITH RESPECT TO THE OUTFLOW
   ASSOCIATED WITH THIS MCS WILL CONTINUE TO SUPPORT BACKBUILDING ALONG
   THE SWRN FLANKS. RADAR TRENDS ALSO SHOW STORMS ALONG ERN FLANKS HAVE
   EVOLVED INTO A MORE LINEAR STRUCTURE AND ARE TRYING TO FORWARD
   PROPAGATE. HOWEVER...RELATIVELY COOL AND STABLE AIR DOWNSTREAM
   ACROSS LOWER MI SHOULD LIMIT INTENSITY AND DOWNDRAFT POTENTIAL OF
   ANY FORWARD PROPAGATING STORMS. THE LOW LEVEL JET IS FORECAST TO
   VEER AND WEAKEN WITH TIME AS NRN STREAM SHORTWAVE CONTINUES EWD
   THROUGH SERN CANADA...AND SOME WEAKENING OF THE STORMS MAY OCCUR
   WITHIN THE NEXT COUPLE HOURS.
   
   ..DIAL.. 05/20/2004
   
   
   ATTN...WFO...GRR...
   
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