Mesoscale Discussion 0850 NWS Storm Prediction Center Norman OK 0649 PM CDT Sun May 24 2026 Areas affected...southwest Minnesota...southeast South Dakota...northwest Iowa...and northeast Nebraska Concerning...Severe Thunderstorm Watch 243... Valid 242349Z - 250145Z The severe weather threat for Severe Thunderstorm Watch 243 continues. SUMMARY...The threat for mainly large hail (up to 2") is expected to continue this evening. DISCUSSION...As of 0045 UTC, radar data showed strong to severe thunderstorms ongoing across southwest MN, including a couple supercells located north and northeast of New Ulm. Those storms are moving through the northeast extension of the low-level moisture axis with objective analysis indicating MLCAPE of 500-1000 J/kg. However, the presence of stronger mid/high-level flow is resulting in elongated hodographs, which will continue to favor supercell storm modes with an associated risk for mainly large hail. As, such a local extension in area may be required to accommodate the ongoing hail threat. The storms may begin to weaken as they shift east of the I-35 corridor south of the Minneapolis metropolitan area owing to a progressively drier boundary-layer with eastward extent. Additional supercell structures have been observed in southeast SD, west of Yankton, with a recent report of 2" diameter hail. Those storms are located within the center of the instability axis, with MLCAPE as high as 1500-2000 J/kg, per objective analysis. Given the presence of 30-35 kt of deep-layer shear, the environment will remain supportive of supercell storm modes for the next few hours with an associated risk for hail up to 2.0" in diameter. Farther south in northeast NE, storms are gradually intensifying south and southeast of O'Neill, as they encounter an increasingly moist boundary layer with similar MLCAPE values to those in southeast SD. Current thinking is that those storms should continue to strengthen this evening as they progress east, with the most intense storms capable of large hail. ..Mead.. 05/24/2026 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...MPX...DMX...FSD...OAX...ABR...GID...LBF... LAT...LON 41789920 42869925 43459911 43559784 44199774 44219720 44529711 44519646 45299641 45319425 44769371 44109392 42909526 42479622 41869643 41299726 41479845 41789920 MOST PROBABLE PEAK WIND GUST...UP TO 60 MPH MOST PROBABLE PEAK HAIL SIZE...1.50-2.50 IN
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