MESOSCALE DISCUSSION 2178
   NWS STORM PREDICTION CENTER NORMAN OK
   1213 AM CST SUN DEC 02 2007
   
   AREAS AFFECTED...CNTRL/SRN LOWER MI...FAR NERN IND...NRN OH
   
   CONCERNING...FREEZING RAIN 
   
   VALID 020613Z - 021015Z
   
   ONGOING SIGNIFICANT FREEZING RAIN EVENT OVER CNTRL/S-CNTRL LOWER MI
   WILL SHIFT EWD AND GRADUALLY DIMINISH IN INTENSITY OVERNIGHT AS THE
   LLJ VEERS AND WEAKENS. ICE ACCUMULATION RATES INITIALLY OF 0.05 TO
   0.15 IN/HR SHOULD DROP TO AOB 0.05 IN/HR BY 12Z.
   
   A 70 KT LLJ CENTERED FROM CNTRL IL INTO SWRN LOWER MI HAS MAINTAINED
   STRONG WARM/MOIST ADVECTION ABOVE A SURFACE-BASED BELOW-FREEZING
   LAYER...RESULTING IN SIGNIFICANT ICE ACCUMULATIONS OVER THE PAST FEW
   HOURS ACROSS CNTRL/SRN LOWER MI INTO EXTREME NRN IND. LATEST MODEL
   GUIDANCE FORECASTS SUGGEST THE LLJ WILL DIMINISH IN INTENSITY AND
   SHIFT EWD FOCUSING STRONGEST ASCENT TOWARDS THE ERN GREAT LAKES
   THROUGH 12Z. AS SUCH...CURRENT BAND OF MODERATE FREEZING RAIN
   CENTERED FROM AROUND 20 W FNT TO JXN TO 40 E SBN WILL LIKELY PUSH
   ACROSS SERN LOWER MI INTO FAR NRN OH AND WEAKEN IN INTENSITY
   OVERNIGHT. BOTH DETERMINISTIC AND ENSEMBLE GUIDANCE SUGGESTS VEERING
   LOW-LEVEL WINDS WILL HELP WARM SURFACE WET-BULB TEMPERATURES ABOVE
   FREEZING DOWNSTREAM OF THIS BAND. HOWEVER...WITH CURRENT SURFACE WET
   BULB TEMPERATURES HOLDING AROUND 27 TO 30 DEGREES...ICE
   ACCUMULATIONS REMAIN PROBABLE THROUGH AT LEAST 10Z.
   
   ..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...CLE...ILN...DTX...IWX...GRR...
   
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