Storm Prediction Center Mesoscale Discussion 1809

   Mesoscale Discussion 1809
   NWS Storm Prediction Center Norman OK
   1249 PM CDT Sun Jul 27 2025

   Areas affected...west-central Minnesota...far eastern South Dakota

   Concerning...Severe potential...Watch possible 

   Valid 271749Z - 271945Z

   Probability of Watch Issuance...60 percent

   SUMMARY...An isolated supercell may persist for a couple hours,
   producing large hail and localized damaging winds. We are monitoring
   for expansion in areal coverage, in which case a watch could be
   needed.

   DISCUSSION...Within a steep midlevel lapse rate environment, an area
   of midlevel convection moving out of northeast SD has erupted into a
   large supercell, currently ongoing over west-central MN. This cell
   is firmly within an 850 mb theta-e advection zone, with strong
   overall instability in this axis.

   While the surface air mass just south/southeast of this cell may
   contain CIN initially, the combination of heating and eventual
   outflow production may result in additional development along the
   southwest flank. Indeed, latest visible satellite images indicate
   new towers extending southwestward across the MN/SD border, which
   could be developing just above the surface. At the very least, it
   indicates unstable inflow into the existing cell/developing complex,
   with some possibility of expansion. Given the robustness and size of
   this isolated storm, a watch cannot be ruled out, but is more likely
   if the overall size/coverage can increase in the near term.

   ..Jewell/Guyer.. 07/27/2025

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

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

   LAT...LON   45429607 45509525 45489455 45329445 45079448 44679459
               44459478 44239582 44219682 44379727 44569735 45259642
               45429607 

   MOST PROBABLE PEAK TORNADO INTENSITY...85-115 MPH
   MOST PROBABLE PEAK WIND GUST...65-80 MPH
   MOST PROBABLE PEAK HAIL SIZE...1.50-2.50 IN