ZCZC SPCSWOMCD ALL ACUS11 KWNS 271236 SPC MCD 271236 MNZ000-SDZ000-271530- MESOSCALE DISCUSSION 0207 NWS STORM PREDICTION CENTER NORMAN OK 0736 AM CDT THU MAR 27 2014 AREAS AFFECTED...NERN SOUTH DAKOTA INTO PARTS OF N CNTRL MINNESOTA CONCERNING...HEAVY SNOW VALID 271236Z - 271530Z SUMMARY...A BAND OF HEAVY SNOW IS EXPECTED TO DEVELOP THIS MORNING...WITH RATES IN EXCESS OF 1 INCH PER HOUR...FROM AROUND WATERTOWN SD BY 14-15Z...THROUGH THE BRAINERD AREA OF CENTRAL MINNESOTA BY 17Z. DISCUSSION...AS A VIGOROUS MID-LEVEL SHORT WAVE TROUGH PROGRESSES NORTHEASTWARD ACROSS THE CENTRAL PLAINS...TOWARD THE MID MISSOURI VALLEY...A MID-LEVEL DEFORMATION ZONE APPEARS TO BE SETTING UP ROUGHLY ALONG AN AXIS FROM WATERTOWN SD THROUGH AREAS NEAR/SOUTH OF BRAINERD MN. THIS WILL LEAD TO STRENGTHENING FRONTOGENETIC FORCING...AND ASSOCIATED INCREASING UPWARD VERTICAL MOTION...PARTICULARLY IN THE 700-500 MB LAYER...WITHIN WHICH RESIDE TEMPERATURES FAVORABLY COLD FOR LARGE DENDRITIC ICE CRYSTAL GROWTH. EVAPORATION OF PRECIPITATION FROM ALOFT WILL CONTINUE TO COOL AND SATURATE A LOWER/MID TROPOSPHERIC LAYER /INITIALLY WARM WITH SIZABLE TEMPERATURE-DEW POINT SPREADS/ DURING THE NEXT COUPLE OF HOURS AROUND THE WATERTOWN SD AREA. THIS IS WHERE LOW-LEVEL COLD ADVECTION TO THE NORTH OF AN INITIAL SURFACE LOW CENTER IS ALREADY UNDERWAY...AND THERMODYNAMIC PROFILES /INCLUDING PRECIPITABLE WATER CONTENT ABOVE .50 INCHES/ PROBABLY WILL BECOME SUPPORTIVE OF HEAVY SNOW RATES IN EXCESS OF 1 INCH BY 14-15Z. MODELS SUGGEST THAT THE INITIAL LOW WILL WEAKEN AS IT SHIFTS FROM SOUTHEASTERN SOUTH DAKOTA INTO SOUTHWEST MINNESOTA. BUT...AS THE PRIMARY SURFACE CYCLONE GRADUALLY MIGRATES FROM THE CENTRAL KANSAS/NEBRASKA BORDER TOWARD THE OMAHA AREA THROUGH MIDDAY...AN INCREASING NORTHERLY LOW-LEVEL FLOW COMPONENT ACROSS CENTRAL MINNESOTA SHOULD RESULT IN SUFFICIENT COOLING FOR THE DEVELOPMENT OF HEAVY SNOW DURING THE 15-17Z TIME FRAME. ..KERR.. 03/27/2014 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...DLH...MPX...FGF...FSD...ABR... LAT...LON 44789804 45709707 46759388 45979326 45189547 44479687 44369767 44789804 NNNN