MESOSCALE DISCUSSION 1885
   NWS STORM PREDICTION CENTER NORMAN OK
   0830 PM CDT TUE SEP 04 2012
   
   AREAS AFFECTED...CNTRL/E-CNTRL WI...NERN IA...FAR WRN UP OF MI...FAR
   NRN IL
   
   CONCERNING...SEVERE THUNDERSTORM WATCH 614...
   
   VALID 050130Z - 050230Z
   
   THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 614
   CONTINUES.
   
   SUMMARY...LOCAL EXTENSION OF THE WW WILL LIKELY BE REQUIRED AS TSTM
   ACTIVITY CONTINUES TO PROGRESS EWD AND MOVES OUT OF THE CURRENT
   WATCH AREA. TSTM ACTIVITY SHOULD CONTINUE FOR ANOTHER HOUR OR TWO
   BEFORE BEGINNING A WEAKENING TREND.
   
   DISCUSSION...TSTM ACTIVITY ACROSS THE WATCH AREA HAS EVOLVED INTO
   THREE SEPARATE LINE SEGMENTS. THE FIRST IS MOVING EWD ACROSS LAKE
   SUPERIOR AND ONTO THE WRN COAST OF MICHIGAN/S UPPER PENINSULA. THIS
   ACTIVITY HAS SHOWN SOME INTENSIFICATION DURING THE PAST HOUR BUT A
   DIMINISHING TREND IS ANTICIPATED AS THE BOUNDARY LAYER CONTINUES TO
   COOL. THE SECOND IS ACROSS CNTRL WI AND HAS EXHIBITED AN INCREASE IN
   FORWARD-PROPAGATION DURING THE LAST HOUR. LATEST KGRB RADAR IMAGERY
   SHOWS THE OUTFLOW IS BEGINNING TO PUSH AHEAD OF THE LINE AND A
   WEAKENING TREND IS EXPECTED DURING THE NEXT HOUR WITH THIS LINE OF
   STORMS AS WELL. THE THIRD IS MOVING SWD ACROSS SRN WI INTO FAR NWRN
   IA AND POSSIBLY NRN IL. THIS SEGMENT EVOLVED FROM A CLUSTER OF
   SUPERCELLS AROUND AND SE OF LSE AND THE ARX VAD WIND PROFILE SHOWS A
   DECENT REAR INFLOW JET SIGNATURE. THIS SIGNATURE HAS BEEN GRADUALLY
   WEAKENING AS THE LINE MOVES FARTHER S. THE MATURE NATURE OF THIS
   LINE MAY ALLOW IT TO CONTINUE FOR LONGER THAN THE OTHER TWO LINES
   PREVIOUSLY MENTIONED...BUT IT TOO WILL ENCOUNTER AN INCREASINGLY
   MORE STABLE ENVIRONMENT AS THE BOUNDARY LAYER COOLS/DECOUPLES. THE
   ERN PORTION OF THE LINE /NEARING MKE/...HAS RECENTLY ACCELERATED EWD
   AS THE OUTFLOW PUSHES SEWD. THIS SEEMS TO SIGNAL THAT THIS PORTION
   OF THE STORM WILL BEGIN WEAKENING SHORTLY BUT IT MAY REMAIN CAPABLE
   OF PRODUCING A FEW SVR GUSTS IN NRN IL. A DOWNSTREAM WW MAY BE NEED
   ACROSS THIS AREA.
   
   ..MOSIER.. 09/05/2012
   
   
   ATTN...WFO...MQT...GRB...LOT...MKX...DVN...DLH...ARX...MPX...
   DMX...
   
   LAT...LON   48189180 48049140 48239087 48099067 48018978 47968860
               47238861 47028898 45488907 45478946 45168943 45098921
               45038922 45048899 44958899 44958876 44668778 44338775
               44248804 43918805 43988958 43648959 43658894 43638841
               43218843 43198853 42848854 42838831 42488830 42358830
               42378896 42378991 42218989 42199024 42209298 43219301
               43219254 43529253 43519175 43849173 43859133 44119114
               44609114 44599090 45399094 45389066 45649064 45649152
               46769154 47169178 48189180