SPC MD 926

Source: spc.noaa.gov · Published: 2026-06-01

MD 0926 CONCERNING SEVERE POTENTIAL...WATCH POSSIBLE FOR SOUTHEAST SOUTH DAKOTA INTO EASTERN NEBRASKA AND FAR WESTERN IOWA <![CDATA[<br /><a href="https://www.spc.noaa.gov/products/md/md0926.html"><img src="https://www.spc.noaa.gov/products/md/mcd0926.png" border="1" alt="MD 0926 Image" hspace="1" vspace="1" width="815" height="611" align="center" /></a><pre>

Mesoscale Discussion 0926 NWS Storm Prediction Center Norman OK 0726 PM CDT Sun May 31 2026

Areas affected...Southeast South Dakota into eastern Nebraska and far western Iowa

Concerning...Severe potential...Watch possible

Valid 010026Z - 010230Z

Probability of Watch Issuance...40 percent

SUMMARY...Additional severe thunderstorm development is possible along the I-29 corridor through the late evening hours. Confidence in storm coverage is limited, but conditions are being monitored for watch issuance.

DISCUSSION...A supercell with a history of at least one brief tornado, along with several additional attempts at sustained deep convection, to the west of the Sioux Falls, SD have been monitored over the past hour for storm maintenance/longevity after several earlier failed attempts at robust convection. This supercell has shown resistance to destructive interference as it shifts east away from the initiating boundary and into an environment with relatively weak low-level shear (but 30-35 knots of 0-6 km BWD) based on the nearby KFSD VWP. Additionally, new cell development south of the supercell has shown steadily increasing echo tops, suggesting that these cells may also be sustained and could pose a severe threat in the coming hours.

Further south, several low-level confluence bands are noted in surface observations and GOES imagery intersecting the primary surface trough/dryline. Percolating congestus is also noted at one intersection near the Omaha, NE area. Based on these trends and some recent high-res guidance, additional thunderstorm development along this boundary appears possible through 04 UTC. Storms that develop along the boundary will likely pose a threat for large hail and severe gusts given adequate buoyancy and deep-layer shear. Marginal low-level SRH away from the boundaries will likely modulate any further tornado threat, but another brief tornado or two could occur given focused low-level vorticity along the surface boundary intersections. Watch issuance may be needed if convection becomes sufficiently widespread in the coming hours.

..Moore/Guyer.. 06/01/2026

...Please see www.spc.noaa.gov for graphic product...

ATTN...WFO...FSD...OAX...GID...

LAT...LON 43169645 41559584 40949571 40789580 40709606 40709631 41209734 41659750 43659774 43899774 44059752 44099711 44049687 43849668 43569648 43169645

MOST PROBABLE PEAK TORNADO INTENSITY...UP TO 90 MPH MOST PROBABLE PEAK WIND GUST...55-70 MPH MOST PROBABLE PEAK HAIL SIZE...UP TO 1.25 IN

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