347
ACUS11 KWNS 042012
SWOMCD
SPC MCD 042012
MNZ000-IAZ000-SDZ000-042145-

Mesoscale Discussion 0980
NWS Storm Prediction Center Norman OK
0312 PM CDT Thu Jun 04 2026

Areas affected...eastern South Dakota into southwestern Minnesota

Concerning...Severe potential...Watch possible

Valid 042012Z - 042145Z

Probability of Watch Issuance...60 percent

SUMMARY...Thunderstorm coverage is expected to increase across
eastern South Dakota and southwestern Minnesota this
afternoon/evening, with potential for large hail and strong to
severe wind gusts.

DISCUSSION...Thunderstorm coverage has increased over the past hour
across portions of eastern South Dakota along/ahead of a slow moving
surface cold front currently extending southwestward from near the
ND/SD/MN border to south-central South Dakota. Ahead of this
boundary, latest objective analysis indicates lingering inhibition
is eroding, with warming temperatures contributing to MLCAPE of
1500-2000 J/kg. While a marginal increase in mid-level flow is
expected through the evening, effective shear will remain weaker
than areas farther west (generally remaining less than 30-35 kts).
This is likely to support an initially discrete storm mode (with
marginal supercell structures possible) with a gradual transition to
a more outflow-dominant, multicellular storm mode.

While mid-level lapse rates are not as steep compared to areas
farther west (evident via a comparison of the 18z UNR and ABR
observed soundings), large hail will be possible with initially
discrete convection and more robust updrafts. Steep low-level lapse
rates will also promote a risk for strong to severe wind gusts. A
brief tornado/landspout also cannot be ruled out should a stronger
low-level updraft interact with marginally enhanced surface vertical
vorticity/low-level shear in close proximity to the surface front.
Trends are being monitored for possible Severe Thunderstorm Watch
issuance.

..Chalmers/Mosier.. 06/04/2026

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

ATTN...WFO...MPX...FGF...FSD...ABR...

LAT...LON   43289941 44029936 44139934 44389861 44659813 45099763
            45509739 45699705 45799668 45879633 45879600 45789562
            45639553 45419544 44919541 44349567 43849607 43349652
            43089737 43049813 43029869 43079917 43289941

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