[MCD] SWOMCD

Fri Dec 30 00:07:42 UTC 2005

ACUS11 KWNS 300008
SWOMCD
SPC MCD 300008 
IAZ000-MNZ000-WIZ000-SDZ000-NEZ000-300415-

MESOSCALE DISCUSSION 2600
NWS STORM PREDICTION CENTER NORMAN OK
0608 PM CST THU DEC 29 2005

AREAS AFFECTED...SE SD...SRN MN...NRN IA

CONCERNING...WINTER MIXED PRECIPITATION 

VALID 300008Z - 300415Z

A LARGE AREA OF FREEZING RAIN MIXED WITH SNOW WILL SPREAD EWD AND
GRADUALLY CHANGE OVER TO ALL SNOW ACROSS SE SD...SRN MN AND NRN IA.

WATER VAPOR IMAGERY CURRENTLY SHOWS AN UPPER-LEVEL TROUGH OVER WRN
SD AND WRN NEB WITH A DRY SLOT AND DEFORMATION ZONE EXPANDING EWD
ACROSS ERN SD AND NE NEB. STRONG LIFT ASSOCIATED WITH THE LEFT FRONT
QUADRANT OF THE MID-LEVEL JET AND STRONG DIVERGENCE ALOFT SHOWN ON
THE SHORT-TERM MODEL FORECASTS IS RESULTING IN WIDESPREAD
PRECIPITATION EXTENDING EWD FROM THE DEFORMATION ZONE. FORECAST
SOUNDINGS ACROSS SRN MN AND NRN IA SHOW AN ABOVE FREEZING LAYER FROM
900 TO 800 MB. AS THE SYSTEM DRIFTS EWD TONIGHT THIS WARM LAYER WILL
ERODE FROM WEST TO EAST RESULTING IN A CHANGEOVER TO ALL SNOW.
ISOLATED HEAVY SNOWFALL RATES OF GREATER THAN 1 INCH PER HOUR WILL
BE POSSIBLE ESPECIALLY AS THE WRAP AROUND ASSOCIATED WITH THE
MID-LEVEL LOW DRIFTS EWD INTO SE SD AROUND MIDNIGHT. THIS AREA OF
HEAVIER SNOWFALL SHOULD DRIFT EWD INTO SRN MN AND NRN IA DURING THE
OVERNIGHT HOURS.

..BROYLES.. 12/30/2005

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

ATTN...WFO...ARX...MPX...DMX...FSD...OAX...ABR...

42689337 42759776 43299893 43989893 44699749 44759354
44239166 43159141 

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