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 

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

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

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

   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