MESOSCALE DISCUSSION 0162
   NWS STORM PREDICTION CENTER NORMAN OK
   1104 PM CST SUN FEB 27 2011
   
   AREAS AFFECTED...CNTRL AND PORTIONS OF SRN LOWER MI
   
   CONCERNING...WINTER MIXED PRECIPITATION 
   
   VALID 280504Z - 281100Z
   
   A MIX OF PRECIP TYPES WILL OVERSPREAD CNTRL AND PORTIONS OF SRN
   LOWER MI OVERNIGHT TONIGHT. FREEZING RAIN IS EXPECTED TO
   OCCUR...MAINLY ACROSS SRN LOWER MI...WITH RATES OF 0.05 INCH PER
   HOUR POSSIBLE.
   
   A LARGE SHIELD OF STRATIFORM PRECIP WITH EMBEDDED CONVECTIVE
   ELEMENTS WILL OVERSPREAD THE DISCUSSION AREA OVERNIGHT TONIGHT. THIS
   ACTIVITY WILL BE SUSTAINED BY INCREASING LOW/MID-LEVEL FRONTOGENESIS
   ASSOCIATED WITH A SHORTWAVE TROUGH. AT 04Z...SFC OBSERVATIONS
   INDICATE THAT THE FREEZING LINE EXTENDS FROM CNTRL PORTIONS OF THE
   THUMB OF LOWER MI TO NEAR MKG. AS SFC LOW PRESSURE ACCELERATES NEWD
   ACROSS THE LOWER GREAT LAKES REGION...LOW-LEVEL COLD AIR ADVECTION
   WILL INTENSIFY...ALLOW THE SFC FREEZING LINE TO DROP SEWD...MOST
   NOTABLY AFTER 07Z ACCORDING TO THE RUC MODEL.
   
   TO THE NORTH OF THE FREEZING LINE...A MIX OF PRECIPITATION TYPES IS
   EXPECTED...AS HAS BEEN OBSERVED UPSTREAM ACROSS NERN IL THIS
   EVENING. FREEZING RAIN IS MOST LIKELY ACROSS SRN PORTIONS OF THE
   DISCUSSION AREA...WITH RATES OF 0.05 INCH PER HOUR POSSIBLE. THIS
   WILL OCCUR AS AN ELEVATED WARM NOSE FEATURING TEMPERATURES AOA 3C
   ALLOWS FALLING PRECIP TO MELT PRIOR TO FREEZING AT THE SFC...AND
   ELEVATED INSTABILITY / MUCAPE VALUES AOA 100 J/KG PER RUC ANALYSIS /
   SPREADS NWD. THIS COULD SUPPORT THUNDERSTORMS...WHICH WILL BE
   CAPABLE OF PRODUCING LOCALLY HEAVIER FREEZING RAIN. FARTHER
   NORTH...COLDER LOW-LEVEL TEMPERATURES WILL BE MORE SUPPORTIVE OF
   SLEET AND SNOW...WITH THE POTENTIAL FOR SLEET AND SNOW SPREADING
   SEWD AFTER 07Z. MOST OF THE PRECIPITATION IS EXPECTED TO MOVE EAST
   OF THE REGION BY 11Z.
   
   ..COHEN.. 02/28/2011
   
   
   ATTN...WFO...DTX...APX...IWX...GRR...
   
   LAT...LON   43028297 42598391 42258492 42058606 42478648 42938666
               43518636 43858488 43978343 43918279 43658253 43028297