MESOSCALE DISCUSSION 2559
   NWS STORM PREDICTION CENTER NORMAN OK
   0104 AM CST WED DEC 22 2004
   
   AREAS AFFECTED...SERN MO/NRN AR...SRN IL/IND...FAR NRN/WRN KY AND
   SERN OH
   
   CONCERNING...PRECIPITATION TRENDS...WINTER PRECIPITATION 
   
   VALID 220704Z - 221300Z
   
   A MIX OF FREEZING RAIN AND SNOW WILL CONTINUE TO DEVELOP OVER THE
   REGION THROUGH 12Z...WITH THE HEAVIEST SNOW /HRLY RATES UP TO 1
   INCH/ ANTICIPATED ALONG A 30 MILE WIDE AXIS CENTERED FROM UNO TO BMG
   THROUGH 13Z. FARTHER SOUTH...THE RAIN SHOULD GRADUALLY CHANGE TO
   FREEZING RAIN ACROSS THE OHIO VALLEY OF SERN OH..NRN/WRN KY  SWWD
   INTO NERN AR.
   
   LATEST TRENDS IN IR IMAGERY INDICATES UPPER LEVEL DYNAMICS WERE
   INCREASING OVER THE REGION AS A STRONG UPPER TROUGH MOVES OUT OF THE
   SRN ROCKIES. STRONGEST FRONTOGENETIC FORCING WILL CONTINUE TO ORIENT
   ITSELF ALONG THE MID LEVEL FRONTAL ZONE/UPPER JET AXIS FROM NRN AR
   INTO SRN IND OVER THE NEXT 6 HOURS SUPPORTING INCREASING SNOWFALL
   RATES. LOW LEVEL CAA AND SATURATION WILL CONTINUE TO AID IN SWD
   MOTION OF SFC WET BULB FREEZING LINE TO A LITTLE ROCK TO CINCINNATI
   LINE BY 13Z. HOWEVER...AS THE LOW LEVEL CAA SUPPORTS THE SWD
   MOVEMENT OF THE SFC FREEZING LINE...MOD-STRONG WAA IN THE 850-925 MB
   LAYER WILL CONTINUE TO LIMIT THE SWD MOTION OF THIS LAYER/S FREEZING
   ISOTHERM AXIS OVER THE OHIO VALLEY. THUS...A NARROW ZONE...LESS THAN
   50 MILES WIDE OF FREEZING RAIN AS THE PREDOMINANT PTYPE IS
   ANTICIPATED TO DEVELOP SWD AND EXTEND FROM NERN AR INTO FAR WRN/NRN
   KY AND SERN OH BY 13Z.
   
   ..CROSBIE.. 12/22/2004
   
   
   ...NOTICE...
   SPC WINTER WEATHER MESOSCALE DISCUSSIONS WILL BE ISSUED ON A 
   SCHEDULED BASIS...FOUR TIMES A DAY...BETWEEN 00-01 UTC...
   06-07 UTC...12-13 UTC...AND 18-19 UTC AS SIGNIFICANT SHORT
   RANGE WINTER WEATHER EVENTS UNFOLD.  THIS SCHEDULE WILL BE
   USED FROM DECEMBER 1 THROUGH FEBRUARY 28.
   
   ATTN...WFO...ILN...LMK...IND...PAH...ILX...MEG...LSX...LZK...SGF...
   
   38728382 37918554 37548635 36688857 36288925 35659023
   35229172 35619308 36349256 37599043 38418922 39168737
   39468473