MESOSCALE DISCUSSION 0190
   NWS STORM PREDICTION CENTER NORMAN OK
   1246 PM CST THU FEB 21 2013
   
   AREAS AFFECTED...FAR E-CNTRL MO...WRN/SRN IL
   
   CONCERNING...WINTER MIXED PRECIPITATION 
   
   VALID 211846Z - 212245Z
   
   SUMMARY...CONTINUATION/STRENGTHENING OF CURRENT PRECIPITATION IS
   EXPECTED ACROSS MUCH OF THE AREA WITH POTENTIAL FOR SOME MIXED
   PRECIPITATION AS TEMPERATURES WARM ALOFT. SNOWFALL RATES IN EXCESS
   OF 1 INCH/HR ARE POSSIBLE WITH A LOWER POTENTIAL FOR 0.50 INCH/HR
   SLEET RATES FROM STL NWD. ELSEWHERE...MIXED PRECIPITATION WILL
   CONTINUE WITH PRECIPITATION RATES OVER 0.10 INCH/HR POSSIBLE.
   
   DISCUSSION...SURFACE OBSERVATIONS AND RADAR IMAGERY SHOW THE COLUMN
   HAS BECOME COOL AND MOIST ENOUGH TO SUPPORT WINTER PRECIPITATION
   ACROSS THE AREA. CONTINUED WAA ADVECTION WILL SUPPORT AN INCREASE IN
   PRECIPITATION RATES DURING THE NEXT FEW HOURS. THERE IS SOME
   UNCERTAINTY AS TO WHETHER OR NOT THE PRECIPITATION-RELATED COOLING
   WILL OFFSET MID-LEVEL WARMING ASSOCIATED WITH THE STRONG WAA. AS A
   RESULT...A CHANGE OVER FROM SNOW TO MORE MIXED-PRECIPITATION -- I.E.
   SNOW AND SLEET -- MAY NOT OCCUR FROM STL NWD. RECENT RAP SOUNDINGS
   ACROSS THIS AREA ARE TOO WARM AT THE SURFACE AND ALOFT. STILL THERE
   IS AT LEAST A LOW PROBABILITY THAT A TRANSITION TO MORE MIXED
   PRECIPITATION OCCURS WITH THE POTENTIAL FOR ENHANCED PRECIPITATION
   RATES. 
   
   FARTHER S...MIXED PRECIPITATION WILL CONTINUE WILL SOME
   INTENSIFICATION EXPECTED. PRECIPITATION RATES MAY REACH 0.10 INCH/HR
   WILL THE POTENTIAL FOR SIGNIFICANT ICE ACCUMULATIONS.
   
   ..MOSIER.. 02/21/2013
   
   
   ATTN...WFO...PAH...ILX...LSX...
   
   LAT...LON   38999099 39759113 39498946 38768875 37828845 37258894
               37298968 38999099