SPC Issues Mesoscale Discussion For Southern Lower MI Regarding Freezing Rain

You know things are bad when Norman, Oklahoma takes time out from talking about tornadoes to talk about how much ice is going to fall in your state.

CONCERNING...WINTER MIXED PRECIPITATION

   MESOSCALE DISCUSSION 2102
   NWS STORM PREDICTION CENTER NORMAN OK
   1104 AM CST MON DEC 28 2015

   AREAS AFFECTED...PORTIONS OF SRN LOWER MI...NRN IND...AND NWRN OH

   CONCERNING...WINTER MIXED PRECIPITATION 

   VALID 281704Z - 282300Z

   SUMMARY...A MIXTURE OF SNOW...SLEET...AND FREEZING RAIN WILL BE
   POSSIBLE THROUGH 23Z. FREEZING RAIN...WITH RATES UP TO 0.05 INCH/HR
   POSSIBLE...SHOULD BECOME MORE LIKELY WITH TIME.

   DISCUSSION...AS A COMPACT...CLOSED UPPER LOW APPROACHES THE GREAT
   LAKES REGION FROM THE SW...A W-E ORIENTED BAND OF PRECIPITATION
   SHOULD CONTINUE THROUGH THE EARLY AFTERNOON BEFORE ADDITIONAL
   PRECIPITATION MOVES OVER THE REGION FROM IL/WRN IND. CURRENT SFC
   OBSERVATIONS AND RADAR MOSAIC IMAGERY DEPICT A MIX OF ONGOING LIGHT
   TO MODERATE WINTER PRECIPITATION TYPES...WITH SNOW/SLEET BEING
   REPORTED ACROSS MUCH OF SRN LOWER MI...AND FREEZING RAIN IN PORTIONS
   OF NRN IND AND NWRN OH. THE 12Z SOUNDING FROM DETROIT MI CONTAINED A
   SUBSTANTIAL DRY LAYER FROM 900-500 MB...WHICH WILL CONTINUE TO
   ERODE/MOISTEN THROUGH THE AFTERNOON WITH ONGOING PRECIPITATION. ONE
   EFFECT OF THIS MOISTENING WILL BE EVAPORATIONAL COOLING THROUGH THIS
   LAYER TO THE WET-BULB TEMPERATURE...SUPPORTING AN INITIAL BURST OF
   MODERATE SNOW. WITH TIME...HOWEVER...FORECAST WAA MAINLY IN THE
   850-700 MB LAYER WITH THE APPROACH OF THE UPPER LOW SHOULD ALLOW FOR
   A TRANSITION FROM S TO N ACROSS THE MCD AREA TO MAINLY FREEZING RAIN
   THROUGH 22-23Z. FREEZING RAIN RATES UP TO 0.05 INCH/HR APPEAR
   POSSIBLE GIVEN ONGOING RADAR/OBSERVATIONAL TRENDS AND HI-RES MODEL
   QPF GUIDANCE...WITH SOME LOCALLY HIGHER RATES NOT OUT OF THE
   QUESTION. CONTINUED LOW-LEVEL WAA MAY ALLOW FOR A TRANSITION TO
   LIQUID RAIN ACROSS SRN PORTIONS OF THE MCD AREA BY EARLY THIS
   EVENING AS THE SFC TEMPERATURE CLIMBS AT OR ABOVE FREEZING.

   ..GLEASON.. 12/28/2015

The technical details aside, only one thing really matters: 0.05 inches per hour of freezing rain possible for the highlighted areas through 6PM tonight. If those figures pan out, this ice will cause power outages, and they will be widespread.