Storm Prediction Center Mesoscale Discussion 1461

   Mesoscale Discussion 1461
   NWS Storm Prediction Center Norman OK
   0453 PM CDT Thu Jun 26 2025

   Areas affected...portions of far southeast Minnesota into central
   and southern Wisconsin

   Concerning...Tornado Watch 463...

   Valid 262153Z - 270000Z

   The severe weather threat for Tornado Watch 463 continues.

   SUMMARY...A threat for severe wind gusts and tornadoes should
   persist over the next few hours. This severe threat may accompany
   storms within an east-ward-progressing QLCS, or with storms that
   develop ahead of the QLCS and interact favorably with a
   quasi-stationary front. A downstream Tornado Watch issuance may be
   needed if confidence increases in more robust, downstream storms
   materializing.

   DISCUSSION...A loosely organized QLCS continued to track eastward
   across far eastern MN into WI, and is traversing a quasi-stationary
   front. Along this front, rich low-level moisture and steep low-level
   lapse rates are contributing to 2000-2500 J/kg MLCAPE. Along with
   this appreciable instability is 35-45 kts of effective bulk shear
   that is overspreading the boundary. Furthermore, regional VADs show
   hodographs with modest curvature and 200-300 m2/s2 of 0-1 km SRH. As
   such, ambient conditions along this boundary are favorable for the
   development of severe gusts and tornadoes.

   At the moment, the tornado threat could increase in southern WI
   under two scenarios. First is with QLCS segments that traverse the
   boundary, optimizing the ingestion of locally higher streamwise
   vorticity. The second scenario involves the maturation of
   free-warm-sector thunderstorms into supercells that can produce
   tornadoes while crossing the boundary and briefly ingesting
   cross-wise vorticity. Convective trends are currently being
   monitored for further storm intensification under either scenario
   and the subsequent need for a Tornado Watch issuance.

   ..Squitieri/Guyer.. 06/26/2025

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

   ATTN...WFO...GRB...MKX...ARX...

   LAT...LON   44469159 44299007 43738863 43198775 42608831 42578921
               42588987 42659035 42799079 42959111 43159131 43309155
               43389165 44469159 

   MOST PROBABLE PEAK TORNADO INTENSITY...85-115 MPH
   MOST PROBABLE PEAK WIND GUST...55-70 MPH