MESOSCALE DISCUSSION 2248
   NWS STORM PREDICTION CENTER NORMAN OK
   1205 PM CST THU NOV 30 2006
   
   AREAS AFFECTED...PORTIONS S-CENTRAL MO AND EXTREME NRN AR THROUGH
   CENTRAL/NERN IL.
   
   CONCERNING...FREEZING RAIN 
   
   VALID 301805Z - 302230Z
   
   ONGOING AXIS OF FREEZING RAIN FROM SWRN MO TO CENTRAL IL IS EXPECTED
   TO REMAIN NEARLY STATIONARY...HOWEVER ACCOMPANYING SWATH OF FREEZING
   RAIN SHOULD EXPAND LATERALLY -- NWD AND SWD THROUGH MID-AFTERNOON. 
   ADDITIONALLY...FREEZING RAIN MAY DEVELOP NEWD THROUGH BROADER AREA
   OF CENTRAL/NERN IL BY 21Z.  BRIEF/LOCAL PRECIP RATES .25-.5
   INCH/HOUR ARE POSSIBLE IN HEAVIER SHOWERS -- AND OVER
   OZARKS...ISOLATED TSTMS.  RATES OF .05-.10 INCH/HOUR  SHOULD BECOME
   MORE COMMON.
   
   MAIN SFC CYCLONE IS ANALYZED OVER SWRN AR AND IS BEGINNING TO
   DEEPEN...WITH INVERTED TROUGH EXTENDING NWWD ACROSS CENTRAL OK. 
   INTENSE SFC FRONT IS ANALYZED FROM AR LOW NEWD ACROSS NWRN
   TN...THROUGH WEAK MESOLOW OVER SRN INDIANA/NWRN KY.  IN BOUNDARY
   LAYER...BAROCLINIC GRADIENT ASSOCIATED WITH FRONT WILL TIGHTEN AS
   WEAK SFC DIABATIC HEATING AND SFC WAA OCCUR IN WARM
   SECTOR...EVAPORATIVE/PRECIP COOLING IN DRY/COLD ADVECTION REGIME
   CONTINUES N OF FRONT...AND LOW LEVEL FRONTOGENETIC FORCING
   INTENSIFIES WITH APCH OF STRONG MID-UPPER TROUGH NOW OVER SRN HIGH
   PLAINS.  NET RESULT AT SFC WILL BE GRADUAL SEWD SHIFT OF FREEZING
   LINE OVER SRN MO AND SRN/ERN IL...LIKEWISE EXPANDING FREEZING RAIN
   POTENTIAL SEWD.  MEANWHILE...ELEVATED WAA/MOISTURE TRANSPORT REGIME
   WILL INTENSIFY AS SFC CYCLONE DEEPENS OVER AR...AS EVIDENT IN
   STRENGTHENING OF RUC FCST ISENTROPIC ASCENT IN 297-300K LAYER
   THROUGH 00Z.  THIS SHOULD HELP TO MAINTAIN 150-200 MB DEEP
   SUPERFREEZING LAYER ALOFT.  EXPECT OVERALL EXPANSION/INTENSIFICATION
   OF RAIN SWATH FROM AR TO INDIANA...NRN PORTION OF WHICH WILL COVER
   PROGRESSIVELY MORE AREA N OF SFC FREEZING LINE.
   
   ..EDWARDS.. 11/30/2006
   
   
   ATTN...WFO...IND...PAH...LOT...ILX...LSX...LZK...SGF...TSA...
   
   40768794 40798761 40758750 40558745 40448748 40198778
   38538941 37669016 36669157 36369231 36209280 36039345
   36189373 36319389 37839227 38389157 38689119 39838955
   40528833