MESOSCALE DISCUSSION 2027
   NWS STORM PREDICTION CENTER NORMAN OK
   0337 PM CDT SAT AUG 20 2011
   
   AREAS AFFECTED...SRN LWR MI
   
   CONCERNING...SEVERE THUNDERSTORM WATCH 792...
   
   VALID 202037Z - 202200Z
   
   THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 792
   CONTINUES.
   
   THE REMAINING VALID PORTION OF WW 792 MAY BE CLEARED PRIOR TO THE
   01Z SCHEDULED EXPIRATION...AS THE ONGOING MESOSCALE CONVECTIVE
   SYSTEM SPREADS INTO SOUTHERN ONTARIO.  TRENDS WILL HAVE TO BE
   MONITORED FOR THE POSSIBILITY OF DEVELOPMENT TO THE LEE OF THE LOWER
   GREAT LAKES...MAINLY PORTIONS OF WESTERN NEW YORK STATE...TOWARD THE
   00-02Z TIME FRAME.
   
   20Z SURFACE ANALYSIS INDICATES SOME STRENGTHENING OF THE
   CONVECTIVELY GENERATED SURFACE COLD POOL CENTERED NEAR LANSING...
   AND AN INTENSIFICATION OF CONVECTION APPEARS ONGOING ON ITS LEADING
   EDGE...TO THE WEST AND NORTHWEST OF DETROIT.  CONVECTIVE CLOUD COVER
   DOWNSTREAM OF THE STRONGER STORMS HAS SUBSTANTIALLY FILTERED
   INSOLATION...AND LIMITED STEEPENING OF LOW-LEVEL LAPSE RATES ACROSS
   THE DETROIT METROPOLITAN AREA...BUT ADDITIONAL COLD POOL
   STRENGTHENING COULD STILL BE SUFFICIENT TO CONTRIBUTE TO POTENTIALLY
   DAMAGING WINDS ALONG THE GUST FRONT DURING THE NEXT HOUR OR SO.  THE
   BULK OF THE CONVECTIVE SYSTEM APPEARS LIKELY TO DEVELOP EASTWARD
   ALONG THE FRONTAL ZONE INTO SOUTHERN ONTARIO BY 22Z...WITH
   CONVECTIVE POTENTIAL DIMINISHING IN ITS WAKE ACROSS LOWER MICHIGAN.
   
   ..KERR.. 08/20/2011
   
   
   ATTN...WFO...BUF...CLE...DTX...
   
   LAT...LON   43088276 43748167 44037981 43637890 42827882 42217931
               41868053 41638196 41768299 41998367 42348372 43088276