MESOSCALE DISCUSSION 0049
   NWS STORM PREDICTION CENTER NORMAN OK
   0236 AM CST SUN JAN 27 2013
   
   AREAS AFFECTED...PORTIONS OF NORTH CENTRAL-NERN MO...SOUTH
   CENTRAL-SERN IA AND FAR WEST CENTRAL IL
   
   CONCERNING...FREEZING RAIN 
   
   VALID 270836Z - 271230Z
   
   SUMMARY...LIGHT FREEZING RAIN WITH RATES OF 0.05 INCH/2-3 HR IS
   EXPECTED TO DEVELOP AND MOVE ENEWD OVER PORTIONS OF NORTH
   CENTRAL-NERN MO INTO SOUTH CENTRAL-SERN IA BETWEEN 09-12Z...AND THEN
   AFFECT FAR WEST CENTRAL IL AFTER 12Z. THE DURATION OF THIS FREEZING
   RAIN ACROSS THE DISCUSSION AREA SHOULD BE SHORT-LIVED /1-2
   HOURS/...GIVEN A RELATIVELY SMALL BREADTH OF THE PRECIPITATION BAND
   PER REGIONAL RADAR IMAGERY. THE SURFACE TEMPERATURE ACROSS THE WRN
   HALF OF THE IA AND MO PORTIONS OF THE DISCUSSION AREA SHOULD RISE
   ABOVE 32 F BETWEEN 13-15Z...AND THUS END THE FREEZING RAIN THREAT IN
   THOSE REGIONS.
   
   DISCUSSION...00Z SOUNDINGS INDICATED THE LOWER TROPOSPHERE WAS
   INITIALLY DRY OVER NRN MO/SRN IA WITH 06-08Z SURFACE OBSERVATIONS
   STILL INDICATING 15 DEGREE SURFACE DEWPOINT DEPRESSIONS. AT 08Z...
   REGIONAL RADAR IMAGERY SHOWED A SOMEWHAT NARROW BAND OF LIGHT
   PRECIPITATION EXTENDING FROM SRN NEB EWD THEN SEWD THROUGH ERN KS
   AND FAR NWRN TO SWRN MO. ALTHOUGH SURFACE TEMPERATURES OVER SOUTH
   CENTRAL IA INTO THE WRN PART OF THE DISCUSSION AREA /FROM KCDG TO
   KCOU/ ARE ABOVE 32 F...EVAPORATIVE COOLING ALONG THE LEADING EDGE OF
   THE PRECIPITATION BAND SHOULD RESULT IN TEMPERATURES FALLING BELOW
   32 F. TRENDS IN SURFACE WET BULB TEMPERATURES PER OBJECTIVE ANALYSES
   CONFIRM THIS SCENARIO AS THE 32 F WET BULB ISOTHERM HAS BEEN
   ADVANCING VERY SLOWLY NEWD SINCE 0330Z...AND CURRENTLY RESIDES FROM
   THE IA/NEB BORDER THROUGH NWRN TO SERN MO. MEANWHILE...00Z UPPER AIR
   ANALYSES INDICATED TEMPERATURES OVER SRN IA/NRN MO WERE ALREADY
   ABOVE 0 C AT THE 925 MB AND 850 MB LEVELS...WITH THESE TEMPERATURES
   RANGING FROM +2 TO 4 C. THE 00Z 850 MB TEMPERATURE IN FAR WEST
   CENTRAL IL WAS ALSO ABOVE 0 C.
   
   AN INCREASE IN DEEP LAYER ASCENT WITHIN THE EXIT REGIONS OF SWLY LOW
   LEVEL AND MID LEVEL JETS IMPINGING ON NRN MO/SRN IA INTO THE EARLY
   MORNING WILL AID IN MAINTAINING THE ONGOING BAND OF PRECIPITATION AS
   IT ADVANCES ENEWD. 06Z RAP SUGGESTS THE AIR MASS WILL BECOME
   SUFFICIENTLY MOISTENED BY 10-11Z ACROSS MUCH OF THE DISCUSSION AREA
   WITH FREEZING RAIN THE PRIMARY PRECIPITATION TYPE...ADVANCING INTO
   FAR WEST CENTRAL IL BY 12Z.
   
   ..PETERS.. 01/27/2013
   
   
   ATTN...WFO...LSX...DVN...DMX...EAX...
   
   LAT...LON   39989335 40479399 41159460 41389346 41299267 40999190
               40239112 39249058 38889089 39029183 39599290 39989335