MD 0460 CONCERNING HEAVY SNOW FOR PORTIONS OF NORTH-CENTRAL/NORTHEASTERN SD INTO SOUTHEASTERN ND AND FAR WESTERN MN
Mesoscale Discussion 0460
NWS Storm Prediction Center Norman OK
0345 PM CDT Tue Apr 04 2023
Areas affected...Portions of north-central/northeastern SD into
southeastern ND and far western MN
Concerning...Heavy snow
Valid 042045Z - 050045Z
SUMMARY...Moderate to heavy snow with rates near 1 in/hr (locally
higher) and visibility reductions in blowing snow are possible this
afternoon/evening.
DISCUSSION...Latest water vapor loops and regional VWP data indicate
a strong southwesterly mid/upper-level jet streak crossing the
central Plains, which will continue northeastward this afternoon. As
the left-exit region of the jet streak gradually overspreads the
northern Plains (ND/SD) during the next few hours, a related band of
isentropic ascent (strong 0-3-km veering evident in regional VWP
data) will strengthen over the region. As the strengthening
large-scale ascent intersects the lower portions of a relatively
deep/saturated dendritic growth zone (per 12Z observed and RAP
forecast soundings), the potential for moderate to heavy snow with
rates up to 1 in/hr (locally higher) will increase this
afternoon/evening.
The highest snowfall rates should generally be focused along/north
of a northeast/southwest-oriented 700-mb thermal gradient extending
from southeast ND into north-central SD in the 22-00Z time frame
(and beyond). In addition, given cold surface temperatures and a
tightening surface pressure gradient coincident with the moderate to
heavy snow, blowing snow with visibility reductions are expected.
However, the potential for near-blizzard conditions will become an
increasing concern into the overnight hours as boundary-layer winds
continue to strengthen amid continued snowfall.
..Weinman.. 04/04/2023
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...FGF...ABR...BIS...
LAT...LON 46290064 46919999 47349910 47779826 48019751 47989678
47559630 46939626 46559644 46169709 45759794 45489920
45690050 46290064
