[MCD] SWOMCD

[MCD at goshenarc.org]

ACUS11 KWNS 211900
SWOMCD
SPC MCD 211859 
WIZ000-ILZ000-IAZ000-MNZ000-SDZ000-NDZ000-220000-

MESOSCALE DISCUSSION 0112
NWS STORM PREDICTION CENTER NORMAN OK
1259 PM CST FRI JAN 21 2005

AREAS AFFECTED...ERN SD AND CNTRL/SRN MN INTO WRN WI/NRN IA

CONCERNING...HEAVY SNOW 

VALID 211859Z - 220000Z

SNOW EXPECTED TO CONTINUALLY INCREASE INTO MID AFTERNOON ACROSS
WCNTRL/CNTRL/SCNTRL MN...WITH HEAVY SNOW DEVELOPING ACROSS SE MN/NE
IA/WRN WI AFTER 21Z. SNOW RATES OF 1 IN/HR OR GREATER WILL BE
POSSIBLE FOR SEVERAL HOURS DURATION.

DOWNSTREAM OF SHORTWAVE TROUGH OVER SRN MANITOBA...WATER VAPOR
IMAGERY DEPICTS LEADING MID LEVEL IMPULSES MOVING SEWD ACROSS BOTH
ERN MT/WRN DAKOTAS AND WRN NEB. 12Z UPPER AIR ANALYSIS/PROFILER
NETWORK DEPICTS LOW TO MID LEVEL BAROCLINIC ZONE ORIENTED NW-SE FROM
THE NRN PLAINS INTO THE MID/UPPER MISSISSIPPI VALLEY. IN ACCORDANCE
WITH VOLUMETRIC RADAR TRENDS...HEAVIEST SNOW EXPECTED TO SHIFT SEWD
THROUGH THE AFTERNOON AS DYNAMIC ASCENT OVERSPREADS ELEVATED PORTION
OF BAROCLINIC ZONE.

12Z ETA/15Z RUC DIAGNOSTICS SUGGEST INCREASING WAA/ISENTROPIC ASCENT
IN 285K-295K LAYER ACROSS SRN MN/NRN IA/WRN WI BY MID/LATE
AFTERNOON. ACCORDINGLY HEAVIEST SNOW EXPECTED TO SHIFT SEWD INTO
THIS CORRIDOR AFTER 21Z...AS THERMODYNAMIC PROFILES WILL REMAIN
CONDUCIVE FOR /HEAVY/ SNOW GIVEN FAVORABLE DENDRITIC PROFILES AND
ABSENCE OF ELEVATED MELTING LAYER.

ON PERIPHERY OF HEAVIER SNOW...AREAS OF FZRA AND/OR SLEET WILL EXIST
THROUGH MID AFTERNOON IN CORRIDOR FROM FAR ERN SD INTO NW IA
/ROUGHLY ATY-SPW/ OWING TO 800-850 MB WARM LAYER -- E.G. 12Z ABR/OAX
RAOBS -- ABOVE SHALLOW SUB-FREEZING LAYER.

..GUYER.. 01/21/2005

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

...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...MKX...DVN...DLH...ARX...MPX...DMX...FGF...FSD...ABR...

46359220 44739074 43139013 42359058 42269228 42639423
43799696 44969805 45659785 46629699 47049606 47039391 

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