MESOSCALE DISCUSSION 1039
   NWS STORM PREDICTION CENTER NORMAN OK
   1200 PM CDT TUE MAY 31 2011
   
   AREAS AFFECTED...THE UPPER MS VLY AND UPR GRT LKS
   
   CONCERNING...SEVERE POTENTIAL...WATCH LIKELY 
   
   VALID 311700Z - 311930Z
   
   LATEST SFC ANALYSIS SHOWS A COLD FRONT ARCING SOUTH AND SOUTHEAST
   ACROSS WRN ONT THROUGH WRN WI INTO ERN IA.  THE FRONT IS MOVING ENE
   AT ABOUT 30 KT AND SHOULD EXTEND FROM WRN UPR MI THROUGH CNTRL WI
   INTO FAR ERN IA BY EARLY AFTN.  AHEAD OF THE FRONT...RADAR AND VWP
   DATA SHOW A LOW LVL WIND SHIFT LINE LEFT OVER FROM LAST EVENINGS MCS
   IN THE DAKOTAS/NEB.  THIS LINE IS JUST NOW CROSSING LK MI...AND
   SHOULD CONTINUE ENE AT ABOUT THE SAME SPEED AS THE COLD FRONT. 
   FINALLY...IN THE INCREASINGLY WARM AND UNSTABLE AIR AHEAD OF THE
   WIND SHIFT LINE...TCU ARE GROWING OVER THE NRN HALF OF LWR MI.
   
   ATTM...WATER IMAGERY AND PROFILER/VWP DATA SHOW A STRONG N-S
   SHORTWAVE IMPULSE OVER CNTRL MN BEGINNING TO TAKE ON A NEGATIVE
   TILT.  THIS IMPULSE...MARKED BY AN 80 KT 500 MB JET STREAK ...SHOULD
   ACCELERATE NEWD ACROSS CNTRL/NRN MI LATER TODAY WHILE THE PARENT UPR
   LOW EDGES MORE SLOWLY ENE FROM MB INTO ONT.
   
   COMBINATION OF CONTINUED SFC HEATING...LOW LVL MOISTURE INFLOW...AND
   LARGE SCALE ASCENT WITH UPR IMPULSE EXPECTED TO FOSTER RAPID TSTM
   DEVELOPMENT IN THE NEXT COUPLE OF HOURS ALONG THE COLD FRONT...THE
   WIND SHIFT LINE...AND WITHIN THE TCU FIELD.  GIVEN STRENGTH OF
   DEEP...LARGELY UNIDIRECTIONAL SWLY FLOW AND FAVORABLE THERMODYNAMIC
   SETUP...POTENTIAL WILL EXIST FOR UPSCALE DEVELOPMENT OF THE STORMS
   INTO ONE OR MORE FORWARD-PROPAGATING SQLNS.  EMBEDDED BOWING
   STRUCTURES AND SUPERCELLS IN THE SQLNS WILL HAVE THE POTENTIAL FOR
   VERY DMGG WIND...IN ADDITION TO LARGE HAIL AND POSSIBLY A COUPLE
   TORNADOES.
   
   ..CORFIDI.. 05/31/2011
   
   
   ATTN...WFO...DTX...APX...GRR...MQT...GRB...MKX...DLH...ARX...
   
   LAT...LON   44059036 45549029 46669035 47258982 47408713 46388392
               45278304 44158353 43458536 43658933 44059036