[MCD] SWOMCD

Fri Dec 30 05:45:00 UTC 2005

ACUS11 KWNS 300546
SWOMCD
SPC MCD 300545 
MNZ000-IAZ000-WIZ000-SDZ000-NEZ000-300945-

MESOSCALE DISCUSSION 2603
NWS STORM PREDICTION CENTER NORMAN OK
1145 PM CST THU DEC 29 2005

AREAS AFFECTED...ERN SD...SRN AND CNTRL MN...NRN IA

CONCERNING...HEAVY SNOW 

VALID 300545Z - 300945Z

AREAS OF HEAVY SNOW WILL CONTINUE ACROSS ERN SD...SRN AND CNTRL MN
AND NRN IA DURING THE OVERNIGHT PERIOD. SNOWFALL RATES GREATER THAN
1 INCH PER HOUR WILL BE POSSIBLE IN THE HEAVIER SNOW BANDS.

WATER VAPOR IMAGERY CURRENTLY SHOWS AN UPPER-LOW LOCATED ACROSS THE
CNTRL DAKOTAS. A SHORTWAVE TROUGH EXTENDED SWD ACROSS CNTRL NEB WITH
A DEFORMATION ZONE SETTING UP ACROSS WRN IA AND SERN SD. STRONG LIFT
ASSOCIATED WITH THE TROUGH AND THE LEFT EXIT REGION OF THE MID-LEVEL
JET WILL CONTINUE TO SUPPORT WIDESPREAD SNOWFALL ACROSS THE REGION
OVERNIGHT. FORECAST SOUNDINGS ACROSS SRN MN...ERN SD AND NW IA SHOW
THAT THE WARM LAYER BETWEEN 900 AND 800 MB THAT WAS PRESENT EARLIER
HAS COOLED BELOW FREEZING IN MOST AREAS. AS A RESULT...SNOW WILL BE
THE FAVORED MODE OF PRECIPITATION ALTHOUGH A FEW SPOTS OF FREEZING
RAIN AND/OR SLEET WILL STILL BE POSSIBLE. THE STRONG LARGE-SCALE
ASCENT AND ISENTROPIC LIFT NORTHEAST OF THE DEFORMATION ZONE WILL
CONTINUE TO RESULT IN BANDS OF MODERATE TO HEAVY SNOW. THE HEAVIEST
SNOWBANDS SHOULD BE ACROSS SE SD...FAR NRN IA AND SRN MN WHERE THE
STRONGEST DIVERGENCE ALOFT SHOULD BE LOCATED.

..BROYLES.. 12/30/2005

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

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

42759727 43359805 44569811 45459724 45639572 45579387
44959255 43969202 42919279 42569537 42609557 

WWWW