MD 0389 CONCERNING BLIZZARD FOR PORTIONS OF SOUTH DAKOTA INTO WESTERN MINNESOTA
Mesoscale Discussion 0389
NWS Storm Prediction Center Norman OK
0906 AM CDT Fri Mar 31 2023
Areas affected...portions of South Dakota into western Minnesota
Concerning...Blizzard
Valid 311406Z - 312000Z
SUMMARY...To the north of a rapidly deepening surface cyclone,
widespread heavy snow and blizzard conditions are expected over
portions of SD and MN. heavy snow rates of 1-2 in/hr and widespread
low visibility from blowing snow are expected.
DISCUSSION...As of 1400 UTC, morning WV imagery showed a
well-developed upper low ejecting out of the central Rockies and
into the Plains. At the surface, an associated cyclone over eastern
NE and western IA is expected to rapidly deepen as strong height
falls and dynamic lift from the upper low pass overhead. Already
observed developing over portions of western NE and SD by regional
radar imagery, a broad precipitation shield should expand in
coverage and intensity through the next several hours in response to
the strong dynamic lift and mid-level warm advection. RAP soundings
across central and eastern SD are supportive of widespread heavy
snow with rates of 1-2 in/hr possible within banded structures.
Farther northeast strong mid-level warm advection has left a
resulting warm nose as observed by the 12z MPX sounding. This may
favor some mixed-phase precip and ice through the first part of the
afternoon. Snow should gradually expand northeastward into portions
of western MN tonight as the maximum in dynamic lift shifts with the
trough, and the lower temperature profile cools below freezing.
Concurrent with the risk for heavy snow, the surface low is expected
to rapidly deepen below 990 mb over IA and southern MN as it tracks
slowly northeastward through the day. Surface pressure falls on the
order of 1-2 mb per hour will support very strong gradient winds
along the backside of the surface low. 35-45 mph winds should
develop supporting widespread Blizzard conditions. Blowing snow and
poor visibility should first develop over central SD before slowly
expanding northeastward into eastern SD and MN later this evening.
Poor travel and dangerous winter weather conditions are most likely
over eastern SD this afternoon into the evening.
..Lyons.. 03/31/2023
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...MPX...FGF...FSD...ABR...UNR...
LAT...LON 45959735 45919529 45709443 45439408 45119395 44749411
44379457 43979557 43619785 43189978 43060101 43080186
43310275 43600318 43870333 44290312 44740254 45280104
45609962 45959735
