MESOSCALE DISCUSSION 0065
   NWS STORM PREDICTION CENTER NORMAN OK
   0707 PM CST SUN JAN 14 2007
   
   AREAS AFFECTED...PORTIONS NRN IL...EXTREME SERN WI...SRN
   LM...EXTREME NRN INDIANA...EXTREME NWRN OH...SRN/CENTRAL LOWER MI.
   
   CONCERNING...WINTER MIXED PRECIPITATION 
   
   VALID 150107Z - 150600Z
   
   NEWD MOVING AREA OF PRECIP NOW OVER CENTRAL PORTIONS INDIANA/IL WILL
   MOVE ATOP FREEZING SFC TEMPS IN MI/INDIANA AND ERN WI/IL BORDER
   REGIONS...AND PORTIONS N-CENTRAL/NERN IL...THROUGH 230Z.  THIS
   ACTIVITY WILL BE PRIMARILY IN FORM OF LIGHT FREEZING RAIN WITH RATES
   GENERALLY AOB .10 INCH HOUR...BUT LOCALLY TO .25 INCH/HOUR.  BETWEEN
   3Z-6Z...FREEZING RAIN WITH RATES LOCALLY NEAR .25-.5 INCH/HOUR MAY
   MOVE NEWD ACROSS SRN LOWER MI.  TRANSITION THROUGH MIXED PHASE WITH
   SLEET...THEN TO SLEET/SNOW MIX...IS POSSIBLE WITH NWD EXTENT ACROSS
   S-CENTRAL TO CENTRAL LOWER MI.  ISOLATED SNOW RATES 1-2 INCH/HOUR
   MAY DEVELOP BY 6Z W-CENTRAL LOWER MI.
   
   LOW LEVEL WAA AND MOISTURE TRANSPORT WILL STRENGTHEN ACROSS THIS
   AREA FROM SW-NE AS MID-UPPER LEVEL PERTURBATION NOW OVER CENTRAL
   HIGH PLAINS CONTINUES TO EJECT NEWD.  NRN PORTION OF MOST INTENSE
   ISENTROPIC ASCENT IN 291-297K LAYER WILL OVERLAP SFC FREEZING TEMPS
   ACROSS NERN IL...NRN INDIANA AND SRN LOWER MI BETWEEN 3Z AND
   6Z...CONCURRENT WITH INCREASE IN 850 MB LLJ TO 40-50 KT JUST S OF
   AREA ACROSS CENTRAL/SRN INDIANA AND SRN IL.  850-750 MB LAYER
   FRONTOGENESIS REASONABLY IS PROGGED TO STRENGTHEN OVER THIS AREA
   THROUGH 6Z...AIDING LIFT.  AT SFC...FREEZING LINE IS ANALYZED AT 0Z
   NEAR TOL...SBN...VPZ...NWD ACROSS RELATIVELY WARM LM WATERS...THEN
   SWWD AGAIN ACROSS NRN FRINGES CHI METRO...TO ABOUT 10 N PIA.  PRIND
   CAA AND WEAK WET BULB EFFECTS WILL HELP TO DRIFT THIS LINE SWD OVER
   NRN INDIANA.  HOWEVER FREEZING LINE MAY NOT CHANGE MUCH OVER IL DUE
   TO LACK OF SFC CAA...COMBINED WITH SENSIBLE WARMING FROM DESCENT OF
   RELATIVELY WARM PRECIP THROUGH SATURATED AIR.
   
   RUC FCST SOUNDINGS INDICATE THIS WILL LEAD TO SATURATED...ROUGHLY 7
   KFT DEEP SUPERFREEZING LAYER ACROSS NRN INDIANA...ABOVE SHALLOW
   FREEZING LAYER NEAR SFC.  SUPERFREEZING LAYER SHOULD TRANSITION TO
   4-5 KFT DEPTH OVER SRN LOWER MI...ATOP DEEPER SUBFREEZING BOUNDARY
   LAYER MORE CONDUCIVE FOR SLEET.  WITH NWWD EXTENT IN LOWER
   MI...THERMAL PROFILES ALOFT WILL SUPPORT SNOW.  STEEP LAPSE RATES OF
   6-7 DEG C/KM...IN PORTIONS OF MOST FAVORABLE THERMAL ZONES FOR
   DENDRITIC GROWTH...INDICATE SOME CONVECTIVE SNOW IS POSSIBLE WITH
   LOCALIZED HEAVY RATES.
   
   ..EDWARDS.. 01/15/2007
   
   
   ...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...DTX...APX...IWX...GRR...LOT...MKX...DVN...
   
   41858983 43128761 44258652 44278507 42948295 42028310
   41468363 41328525 41628648 42238670 42488728 42028825
   41828888 41628964 41758988