MESOSCALE DISCUSSION 0055
   NWS STORM PREDICTION CENTER NORMAN OK
   0245 PM CST MON JAN 31 2011
   
   AREAS AFFECTED...E-CNTRL IL/CNTRL IND
   
   CONCERNING...WINTER MIXED PRECIPITATION 
   
   VALID 312045Z - 010145Z
   
   MULTIPLE ROUNDS OF WINTER MIXED PRECIPITATION WILL SHIFT EWD ACROSS
   E CNTRL IL AND CNTRL IND THROUGH LATE AFTERNOON. FREEZING
   RAIN...WITH RATES OF 0.05 TO 0.10 INCH PER 3 HOURS...WILL BE A
   CONCERN ALONG AND SOUTH OF THE INTERSTATE 70 CORRIDOR. ACROSS NORTH
   CNTRL IND...MODERATE TO LOCALLY HEAVY SNOW WITH RATES OF UP TO 1
   INCH PER HOUR COULD OCCUR AFTER 22Z.
   
   A SHIELD OF PRECIPITATION OVER CNTRL IL CONTINUES TO ORGANIZE AND
   SHIFT EWD...WHILE SCATTERED PRECIPITATION IS DEVELOPING FARTHER WSW
   INTO E CNTRL MO. ALL OF THIS ACTIVITY IS IN RESPONSE TO
   WAA/ISENTROPIC UPGLIDE IN THE 285-295 K LAYER ATOP A BROAD
   LOW/MID-LEVEL BAROCLINIC ZONE ACROSS THE OHIO VALLEY REGION. THE
   ASCENT IS FORECAST TO INTENSIFY THROUGH THE AFTERNOON PER THE 19Z
   RUN OF THE RUC MODEL...AS A SWLY LOW-LEVEL JET MAX STRENGTHENS TO
   THE EAST OF AN 850-MB VORT CENTER. CONVERGENCE IN THE EXIT REGION OF
   THIS JET MAX WILL INTERACT WITH THE BAROCLINIC ZONE TO INCREASE
   FRONTOGENESIS ACROSS THE DISCUSSION AREA AND AUGMENT THE LOW-LEVEL
   ASCENT...ALLOWING PRECIPITATION TO BE MAINTAINED AND REGENERATE
   UPSTREAM. WITH WET-BULB ZERO TEMPERATURES AT THE SFC BELOW
   FREEZING...A MIX OF WINTER PRECIPITATION TYPES IS EXPECTED.
   
   ALONG AND SOUTH OF THE INTERSTATE 70 CORRIDOR...FORECAST SOUNDINGS
   INDICATE TEMPERATURES WARMING TO 3-4C IN THE 850-880-MB
   LAYER...ALLOWING PRECIPITATION TO MELT AS IT FALLS THROUGH THE WARM
   NOSE BEFORE FREEZING AT THE SURFACE. FURTHER TO THE
   NORTH...TEMPERATURES IN THE WARM NOSE WILL BE SUFFICIENTLY COLD /AOB
   3C/ TO ALLOW FOR SLEET...WITH SNOW EXPECTED ACROSS N CNTRL IN. THE
   15Z SREF RUN INDICATES THAT SNOWFALL COULD BECOME LOCALLY HEAVY IN
   THIS REGION...AS FRONTOGENETIC FORCING POTENTIALLY SUPPORTS BANDED
   PRECIPITATION. PRECIPITATION WILL LIKELY CONTINUE ACROSS THE REGION
   INTO THE EVENING HOURS.
   
   ..COHEN/ROGERS.. 01/31/2011
   
   
   ATTN...WFO...ILN...IWX...IND...LOT...ILX...
   
   LAT...LON   40668790 41208676 41108509 39918480 39108533 38778636
               38948783 39548816 40668790