[MCD] SWOMCD

[Mesoscale Convective Discussions]

ACUS11 KWNS 281220
SWOMCD
SPC MCD 281219 
MNZ000-IAZ000-NEZ000-SDZ000-NDZ000-281745-

MESOSCALE DISCUSSION 2492
NWS STORM PREDICTION CENTER NORMAN OK
0619 AM CST MON NOV 28 2005

AREAS AFFECTED...NERN NE/ERN SD/MN

CONCERNING...HEAVY SNOW/BLIZZARD CONDITIONS/FREEZING RAIN 

VALID 281219Z - 281745Z

DEEP...CLOSED UPPER LOW WILL MOVE FROM SERN NE TO WRN IA BY 18 UTC.
SYSTEM IS NEARLY VERTICALLY STACKED WITH SURFACE LOW PREDICTED TO
REACH SRN MN BORDER BY 18 UTC...CONSISTENT WITH THE LATEST
MESOANALYSIS SHOWING LARGEST PRESSURE FALLS OVER NCNTRL IA.

10 UTC RUC FORECAST SHOWS ISENTROPIC ASCENT/TROWAL AXIS ON THE 297K
SURFACE TO SHARPEN DURING THE MORNING HOURS AS SNOW RATES EXCEED
1"/HOUR. HEAVIEST SNOW SHOULD SHIFT FROM CNTRL SD/CNTRL NE INTO ERN
SECTIONS OF THESE STATES AS NORTHWEST WINDS OVER 30 TO 40 MPH
PRODUCE BLIZZARD CONDITIONS.

THE REPOSITIONING OF CYCLONE ALSO RESULTS IN COOLING OF LOW LEVEL
AIR MASS IN CNTRL AND NRN MN. EXPECT SURFACE TEMPERATURES TO
DECREASE STEADILY DURING THE MORNING REACHING 32F IN NCNTRL MN BY 13
UTC AND BY 16 UTC IN SCNTRL MN...AND REMAIN BELOW FREEZING REMAINDER
OF THE DAY. STILL A RATHER DEEP LAYER OF WARM AIR CENTERED AROUND
850 MB LEVEL WITH LITTLE UNCERTAINTY IN PRECIPITATION TYPE BEGINNING
AS FREEZING RAIN THIS MORNING. FRONTOGENETICAL FORCING ALONG
BAROCLINIC TROUGH AXIS WITH MOIST ADIABATIC LAPSE RATES WILL AID IN
BANDED MODERATE PRECIPITATION AND FREEZING RAIN RATES OF 0.05" TO
0.10" PER HOUR POSSIBLE THROUGH 18 UTC.

SEE THE LATEST HPC FORECASTS FOR PROBABILISTIC HEAVY SNOW AND HEAVY
FREEZING RAIN POTENTIAL AND INFORMATION EXTENDING BEYOND 18 UTC.

..BRIGHT.. 11/28/2005

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

ATTN...WFO...DLH...MPX...FGF...FSD...OAX...ABR...GID...LBF...UNR...

44099930 45369804 46549685 47779500 48069332 47969133
47799085 47259114 46799215 45909351 44949452 43839546
42169696 41419792 41259917 41859980 42530013 43379991 

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