889
ACUS11 KWNS 300904
SWOMCD
SPC MCD 300904
MNZ000-WIZ000-IAZ000-301030-

Mesoscale Discussion 1393
NWS Storm Prediction Center Norman OK
0404 AM CDT Tue Jun 30 2026

Areas affected...Southern MN into northern IA

Concerning...Severe Thunderstorm Watch 421...

Valid 300904Z - 301030Z

The severe weather threat for Severe Thunderstorm Watch 421
continues.

SUMMARY...At least localized severe gusts remain possible through
dawn.

DISCUSSION...Convection associated with a storm cluster over
south-central MN has recently weakened, with CINH tending to weaken
storms along the southern part of the cluster, and more stable
conditions to the north of a frontal boundary constraining
development within the northern part of the cluster. However, strong
to severe gusts continue to be observed, most recently a 52 kt gust
at KJYG in Watonwan County, MN.

Downstream of this cluster, a more favorable environment remains in
place into southeast MN and southwest WI, with MUCAPE of near/above
4000 J/kg and weaker CINH per recent objective mesoanalyses. Even if
the ongoing cluster continues to weaken, some redevelopment and
possible reorganization cannot be ruled out as the primary gust
front/cold pool move into this environment. Some intensification of
trailing convection across northwest IA also remains possible as it
moves east-northeastward through the early morning.

..Dean.. 06/30/2026

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

ATTN...WFO...ARX...MPX...DMX...FSD...

LAT...LON   44209496 44209496 44859439 45089397 45109341 44989286
            44919259 44659227 44129194 43599197 43359231 43309288
            43179465 43509497 43809498 43999496 44209496

MOST PROBABLE PEAK WIND GUST...65-80 MPH
MOST PROBABLE PEAK HAIL SIZE...UP TO 1.25 IN