ACUS11 KWNS 251835
SWOMCD
SPC MCD 251835=20
WIZ000-IAZ000-MNZ000-252030-

Mesoscale Discussion 1436
NWS Storm Prediction Center Norman OK
0135 PM CDT Wed Jun 25 2025

Areas affected...parts of south central and southeastern
Minnesota...adjacent portions of northern Iowa and southwestern
Wisconsin

Concerning...Severe potential...Watch likely=20

Valid 251835Z - 252030Z

Probability of Watch Issuance...80 percent

SUMMARY...Scattered thunderstorm development is increasingly
probable through 3-5 PM CDT, including a few evolving supercell
structures with potential to produce tornadoes.

DISCUSSION...Near the southern periphery of a dissipating convective precipitation shield, strengthening differential surface heating
appears likely to contribute to a better-defined warm frontal zone
across southern Minnesota into adjacent portions of Wisconsin,
near/south of the Redwood Falls, Rochester into La Crosse
vicinities. In the presence of seasonably high boundary-layer
moisture content, including surface dew points around or above 70 F,
it appears that increasing insolation will contribute to rapid
destabilization.

Although lapse rates are generally rather modest on the northwestern
periphery of prominent mid-level ridging still centered across the
Tennessee Valley, forecast soundings suggest that warming, but moist relatively-saturated, boundary-layer parcels will become
characterized by CAPE increasing in excess of 1500 J/kg. It
appears that this destabilization will coincide with enlarging,
clockwise curved low-level hodographs, beneath a strengthening
southwesterly 850 mb jet (20-30 kt), which is forecast to nose
northeastward out of northwestern Iowa during the next few hours.

Decreasing mid/upper-level inhibition with the low-level warming is
expected to lead to deepening convective development and the
initiation of scattered thunderstorm activity through 20-22Z, in an
environment increasingly conducive to the evolution of low-level
mesocyclones. Aided by low-level stretching supported by the high-boundary-layer moisture content/near-surface CAPE, a few of
these may occasionally intensify and become capable of producing
tornadoes.

..Kerr/Hart.. 06/25/2025

...Please see https://urldefense.com/v3/__http://www.spc.noaa.gov__;!!DZ3fj= g!-GsY_uF2-YK8BVn2QEek2vQal1ZPRVY6_3fpzC7DccmXCYT7UQbOiDnwMKan4lW2EZ8QgSitp= mBcBnxYi1d0lBJ5ybA$ for graphic product...

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

LAT...LON 44559317 44499205 44239129 43539143 43329186 43309376
43639459 44119444 44559317=20

MOST PROBABLE PEAK TORNADO INTENSITY...85-115 MPH
MOST PROBABLE PEAK WIND GUST...55-70 MPH
MOST PROBABLE PEAK HAIL SIZE...UP TO 1.25 IN


=3D =3D =3D
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