Mesoscale Discussion 2126
NWS Storm Prediction Center Norman OK
0121 PM CDT Tue Aug 25 2026
Areas affected...portions of eastern Minnesota into northwestern
Wisconsin
Concerning...Severe potential...Watch possible
Valid 251821Z - 252015Z
Probability of Watch Issuance...60 percent
SUMMARY...Thunderstorms forming along an approaching cold front will
bring a risk for large hail, damaging wind gusts, and perhaps a
brief tornado. Watch issuance may be needed.
DISCUSSION...Latest water vapor imagery depicts a well-defined
mid-level shortwave trough centered over southeastern Manitoba, with
surface analysis indicating this low is vertical stacked with its
surface reflection. To the southeast of this feature, an increase in
cumulus development has been noted over the past 30-60 minutes
across portions of northern Minnesota along a surface cold front.
Ahead of this front, temperatures in the mid-to-upper 70s F and 60s
F dewpoints are supporting 1000-1500+ J/kg MLCAPE, with latest
objective analysis suggesting minimal MLCIN remains.
As convective initiation occurs along the front, supercells will be
possible initially. While mid-level lapse rates and effective shear
will generally remain modest (around 6-6.5 C/km and 25-35 kts,
respectively), large hail will be possible, especially farther north
where cooler mid-level temperatures should allow for marginally
steeper mid-level lapse rates. The expectation is then for
multicells/clusters and an associated risk for damaging wind gusts
to be increasingly favored with time as storm coverage increases
through the afternoon along the eastward-progressing front. A brief
tornado also cannot be ruled out given modestly enhanced low-level
shear/hodograph curvature sampled by the Duluth VWP and indicated by
recent mesoanalysis/RAP forecast soundings. A WW may be needed in
the next 1-2 hours pending further convective development.
..Chalmers/Smith.. 08/25/2026
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...DLH...MPX...
LAT...LON 48339145 48279105 48069084 46869081 45379106 44869142
44809197 44879268 45479325 46619375 47529394 48099394
48799380 48759304 48419184 48339145
MOST PROBABLE PEAK TORNADO INTENSITY...UP TO 90 MPH
MOST PROBABLE PEAK WIND GUST...55-70 MPH
MOST PROBABLE PEAK HAIL SIZE...1.00-1.75 IN
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