MESOSCALE DISCUSSION 0194
   NWS STORM PREDICTION CENTER NORMAN OK
   0337 PM CST THU FEB 21 2013
   
   AREAS AFFECTED...CNTRL IL...SERN IA
   
   CONCERNING...HEAVY SNOW 
   
   VALID 212137Z - 220130Z
   
   SUMMARY...DEVELOPMENT OF HEAVY SNOW...WITH RATES AROUND 1
   INCH/HR...IS POSSIBLE DURING THE NEXT FEW HOURS.
   
   DISCUSSION...RADAR IMAGERY SHOWS AN AREA OF PRECIPITATION FROM SERN
   IA SEWD ACROSS CNTRL IL. SURFACE OBSERVATION HAVE RECENTLY STARTED
   REPORTING MODERATE TO HEAVY SNOW...INDICATING THE MID AND LOW-LEVELS
   HAVE MOISTENED ENOUGH TO SUPPORT PRECIPITATION AT THE SURFACE. 
   
   ACROSS SERN IA AND NWRN IL...A MID-LEVEL DRY SLOT...DEMARCATED WELL
   BY DRYING TRENDS IN RADAR IMAGERY ACROSS NERN MO...IS APPROACHING
   THE AREA AND WILL LIKELY RESULT IN ONLY A SHORT PERIOD OF HEAVY
   SNOW...WITH A GENERAL DOWNWARD TREND IN SNOWFALL RATES FROM SW TO
   NE.
   
   ACROSS CNTRL IL...RADAR RETURNS HAVE PERSISTED OVER THE AREA BUT
   SURFACE OBSERVATIONS HAVE ONLY RECENTLY BEGUN REPORTING SNOW. AS THE
   UPPER LOW...CURRENTLY CENTERED OVER THE CNTRL PLAINS...CONTINUES
   NEWD...FORCING FOR ASCENT /PROVIDED BY BOTH WAA AND CVA/ WILL WANE.
   HOWEVER...BEFORE THAT OCCURS...HEAVY SNOW WITH RATES NEAR 1 INCH/HR
   MAY BE OBSERVED FOR THE NEXT FEW HOURS. SOME MODEL GUIDANCE
   INDICATES A TRANSITION BACK TO MIXED PRECIPITATION OVER THE SERN
   PORTION OF THE MD AREA BUT RAP SOUNDINGS ARE CONSIDERABLY TO0 WARM
   /3 TO 5 DEG F TO0 WARM AT THE SURFACE/ AND RECENT TRENDS BACK TO
   SNOW ACROSS SRN IL SUGGEST THE PRIMARY PRECIPITATION TYPE WILL
   REMAIN TO BE SNOW.
   
   ..MOSIER.. 02/21/2013
   
   
   ATTN...WFO...ILX...LSX...DVN...DMX...EAX...
   
   LAT...LON   38778777 38648822 38778905 38938954 39529060 40029134
               40419221 40639309 41209307 41289154 40778980 40328885
               39698789 39188767 38778777