[MCD] SWOMCD

Thu Nov 30 18:03:59 UTC 2006

ACUS11 KWNS 301806
SWOMCD
SPC MCD 301805 
INZ000-ILZ000-MOZ000-ARZ000-302230-

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

...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...

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 