MESOSCALE DISCUSSION 0049
   NWS STORM PREDICTION CENTER NORMAN OK
   0208 AM CST TUE JAN 27 2004
   
   AREAS AFFECTED...INDIANA/OHIO BORDER REGION...SERN LOWER MI
   
   CONCERNING...FREEZING RAIN AND SLEET 
   
   VALID 270808Z - 271245Z
   
   BAND OF FREEZING RAIN -- LOCALLY HEAVY WITH THUNDER POSSIBLE -- IS
   FCST TO MOVE NEWD ACROSS MIE/FWA/TOL AREAS THROUGH 10Z AND OVER
   PORTIONS SERN MI -- INCLUDING DTW/ARB METRO AREA -- DURING 10Z-12Z
   TIME FRAME.  SFC ICING RATES WILL VARY WIDELY...BUT BECAUSE OF
   POTENTIAL FOR EMBEDDED TSTMS...MAY BRIEFLY REACH .75-1 INCH/HOUR
   RANGE IN CORES.  RATES OF .10-.25 INCH/HOUR WILL BE COMMON. FREEZING
   RAIN WILL TRANSITION TO SLEET WITH NWWD EXTENT TOWARD AN IND-BTL-MBS
   AXIS DURING SAME PERIOD.  SLEET RATES SHOULD VARY FROM .25-.75
   INCH/HOUR..THUNDER BEING LESS PROBABLE THAN IN FREEZING RAIN
   CORRIDOR.
   
   SFC ANALYSIS AT 7Z SHOWS FREEZING LINE 50 S BMG 25 N DAY 20 E FDY 20
   S DTW THEN EWD ACROSS LE.  WEAK SFC WAA AND ELY/NELY FLOW FROM LE
   MAY CAUSE FREEZING LINE TO DRIFT WWD SLIGHTLY ACROSS NWRN OH AND
   MONROE COUNTY MI.  OTHERWISE...HOWEVER...OFFSETTING EFFECTS OF SFC
   WAA...EVAPORATIONAL COOLING AND SENSIBLE HEAT FLUX FROM FALLING
   LIQUID PRECIP SHOULD KEEP FREEZING LINE QUASISTATIONARY.  FAVORABLE
   JUXTAPOSITION OF ELEVATED LOW LEVEL WAA/MOISTENING AND STRONG LARGE
   SCALE DPVA -- THAT HAS SUPPORTED CONVECTIVE PRECIP PLUME OVER SRN
   INDIANA -- WILL MAINTAIN THIS PRECIP AREA AS IT SHIFTS NEWD ACROSS
   DISCUSSION AREA.  THIS SCENARIO IS ALSO SUPPORTED BY RUC/ETA
   PRECIP/UVV FIELDS AND TRACK OF MAX 291K ISENTROPIC ASCENT IN RUC. 
   FCST SOUNDINGS INDICATE 3-5 KFT DEEP SUPERFREEZING LAYER ABOVE SFC
   SUPPORTING RAIN PRODUCTION BEFORE DESCENT INTO SHALLOW SUBFREEZING
   SFC LAYER.  LATTER LAYER WILL DEEPEN WITH WWD EXTENT ENCOURAGING
   TRANSITION TO SLEET.  ELEVATED MUCAPE 200-300 J/KG POSSIBLE ABOVE
   SFC FREEZING LINE...DECREASING TO BELOW 50 J/KG OR LESS IN SLEET
   AREA.
   
   ..EDWARDS.. 01/27/2004
   
   
   ATTN...WFO...DTX...IWX...GRR...IND...CLE...ILN...
   
   39988599 39788585 40008647 40568680 42048611 43568408
   43658259 42988242 43008263 41318517 40408580 40028598 
   
   39828490 39718563 40258612 41618537 43238281 42918245
   42638251 42498265 42378283 42358303 42258308 42148312
   42018315 42018340 41888359 41618350 41148352 40808365
   39978460