[MCD] SWOMCD

Sun Mar 12 16:48:52 UTC 2006

ACUS11 KWNS 121650
SWOMCD
SPC MCD 121650 
MNZ000-SDZ000-122115-

MESOSCALE DISCUSSION 0254
NWS STORM PREDICTION CENTER NORMAN OK
1050 AM CST SUN MAR 12 2006

AREAS AFFECTED...CENTRAL/SOUTHERN SD INTO SOUTHWEST MN

CONCERNING...HEAVY SNOW 

VALID 121650Z - 122115Z

SNOW IS EXPECTED TO STEADILY INCREASE/DEVELOP EASTWARD ACROSS
CENTRAL AND SOUTHERN SD...AND EVENTUALLY SOUTHWEST MN...THROUGH THE
AFTERNOON. SNOW RATES OF 1-2 IN/HR WILL BE POSSIBLE WITH THE
HEAVIEST BANDS.

WITH SURFACE CYCLOGENESIS ONGOING ACROSS EASTERN CO AND LEADING
SHORTWAVE TROUGH MOVING OUT OF THE CENTRAL ROCKIES PER WATER VAPOR
IMAGERY...EXIT REGION OF SOUTHERN ROCKIES/CENTRAL PLAINS UPPER JET
AND ONGOING WAA REGIME CONTRIBUTING TO STRONG UVVS ACROSS SD.
SIMILAR TO TRENDS ALREADY OBSERVED IN VOLUMETRIC RADAR DATA ACROSS
SOUTH CENTRAL SD...STRONG MID LEVEL /600-800 MB/ FRONTOGENETICAL
FORCING IN ADDITION TO MODEST POTENTIAL INSTABILITY WILL PROMOTE
WSW-ENE BANDS OF HEAVY SNOW THROUGH THE AFTERNOON. THIS BANDING
TENDENCY AND STRONG UVVS COINCIDENT WITH A DEEPLY SATURATED
DENDRITIC LAYER WILL PROMOTE POTENTIAL FOR 1-2 IN/HR SNOW RATES.
TRENDS/SHORT TERM WRF GUIDANCE SUGGESTS THE HEAVIEST SNOW WILL
LIKELY OCCUR ACROSS CENTRAL/SOUTHERN SD GENERALLY ALONG AND JUST
NORTH OF I-90...AND INTO SOUTHWEST MN BY EARLY THIS EVENING.

..GUYER.. 03/12/2006

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

ATTN...WFO...MPX...FSD...ABR...UNR...

44640284 44930081 45449797 45439609 44519587 44259620
43549785 43190036 43140140 43230230 

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