MESOSCALE DISCUSSION 2177
   NWS STORM PREDICTION CENTER NORMAN OK
   1047 PM CST SAT DEC 01 2007
   
   AREAS AFFECTED...UPPER AND NRN LOWER MI...ARROWHEAD OF MN
   
   CONCERNING...HEAVY SNOW 
   
   VALID 020447Z - 020745Z
   
   A LARGE REGION OF MODERATE TO OCCASIONALLY HEAVY SNOW WITH RATES
   AROUND 1 TO 1.5 IN/HR ATTM...WILL DIMINISH FROM WEST TO EAST THROUGH
   09Z AS MID-LEVEL SUBSIDENCE/DRYING SWEEP EWD.
   
   RECENT SURFACE OBSERVATIONS AND RADAR REFLECTIVITY INDICATE A SWATH
   OF MODERATE SNOW WITH EMBEDDED AREAS OF HEAVY SNOW STRETCHING FROM
   NERN MN SEWD INTO NRN LOWER MI. A LEAD SHORT WAVE TROUGH LOCATED
   OVER THE UPPER MS RIVER VALLEY WILL MOVE NEWD INTO ONTARIO AND
   WEAKEN OVERNIGHT AS PRIMARY LARGE-SCALE TROUGH EJECTS E FROM THE
   ROCKIES ONTO THE HIGH PLAINS. MID-LEVEL ISENTROPIC UPGLIDE WILL
   QUICKLY WANE AFTER TROUGH PASSAGE AND LATEST SHORT-TERM MODEL
   GUIDANCE FORECASTS ARE IN EXCELLENT AGREEMENT WITH SIGNIFICANT
   DRYING COMMENCING WITHIN THE DENDRITIC GROWTH LAYER BETWEEN 06-09Z.
   THIS HAS ALREADY BEEN NOTED IN UPSTREAM SATELLITE IMAGERY WHERE
   CLOUD TOPS HAVE RAPIDLY WARMED ACROSS CNTRL MN AND MUCH OF WI.
   
   ..GRAMS.. 12/02/2007
   
   
   ...NOTICE...
   SPC WINTER WEATHER MESOSCALE DISCUSSIONS WILL BE ISSUED ON A
   SCHEDULED BASIS FROM DECEMBER 1 THROUGH FEBRUARY 28...FOUR
   TIMES A DAY...AROUND 00 UTC...06 UTC...12 UTC...AND 18 UTC
   FOR SIGNIFICANT SHORT RANGE WINTER WEATHER EVENTS.
   
   ATTN...WFO...DTX...APX...GRR...MQT...GRB...DLH...
   
   43848246 43388284 43488356 44078476 45068628 45708746
   46278874 46799104 46909234 47459299 48209235 48269097
   48058937 47408756 46538447 45378323