Mesoscale Discussion 2126
Issued: · Valid: –
Summary
Severe thunderstorms capable of producing large hail, damaging wind gusts, and brief tornadoes may develop across portions of eastern Minnesota and northwestern Wisconsin through the afternoon.
Product Text
000 ACUS11 KWNS 251822 SWOMCD SPC MCD 251821 MNZ000-WIZ000-252015- 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