MD 2084 CONCERNING SEVERE POTENTIAL…WATCH LIKELY FOR PORTIONS OF CENTRAL/NORTHERN MN AND NORTHWESTERN WI
Mesoscale Discussion 2084
NWS Storm Prediction Center Norman OK
0316 PM CDT Tue Sep 05 2023
Areas affected…Portions of central/northern MN and northwestern WI
Concerning…Severe potential…Watch likely
Valid 052016Z – 052215Z
Probability of Watch Issuance…80 percent
SUMMARY…An increasing threat for large hail and severe wind gusts
will likely warrant watch issuance this afternoon.
DISCUSSION…A moist low-level airmass continues to stream northward
this afternoon across the Upper MS Valley ahead of a cold front.
Surface dewpoints in the mid to upper 60s have become common across
much of southern/central MN and western WI. Even with persistent
cloud cover, filtered daytime heating has encouraged temperatures to
generally warm into the 80s across this area. Current expectations
are for thunderstorms to gradually intensify over the next couple of
hours along/near the cold front extending southwest to northeast
across MN as a shortwave trough over the northern Plains moves
northeastward.
Modifying an 18Z observed sounding from MPX for current surface
conditions suggests that lingering MLCIN has largely eroded, with
around 1800 J/kg of MLCAPE present along with steep mid-level lapse
rates. Stronger mid-level flow is expected to remain confined north
of the international border, but modestly enhanced southwesterly
mid-level winds are present across the Upper Midwest to the east of
the upper trough. 30-40 kt of deep-layer shear will support a mix of
multicells and supercells capable of producing both large hail and
severe wind gusts. A modestly strengthening and veering wind profile
with height through low/mid levels may also foster occasional
low-level updraft rotation, with some chance for a tornado or two.
Watch issuance will likely be needed to address the increasing
severe hail/wind threat.
..Gleason/Guyer.. 09/05/2023
…Please see www.spc.noaa.gov for graphic product…
ATTN…WFO…DLH…MPX…
LAT…LON 46089498 47049386 48259258 48389203 48169137 48289087
47998967 46959077 45879202 45339290 45019376 45049445
45459486 46089498
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