Storm Prediction Center Mesoscale Discussion 786

   Mesoscale Discussion 0786
   NWS Storm Prediction Center Norman OK
   1208 PM CDT Thu May 15 2025

   Areas affected...Portions of southern and central Minnesota into
   Northwest Wisconsin

   Concerning...Severe potential...Watch likely 

   Valid 151708Z - 151945Z

   Probability of Watch Issuance...80 percent

   SUMMARY...Severe storms capable of all severe hazards (including
   very large hail and strong tornadoes) are expected this afternoon.
   Timing of storm development is uncertain, but one or more watches
   are likely early this afternoon.

   DISCUSSION...Potent mid-level ascent continues to lift into southern
   and central Minnesota late this morning. Earlier elevated convection
   north of the Twin Cities has weakened substantially and very minimal
   outflow is evident from that activity. A narrow warm sector is
   lifting ahead of a dryline feature. Despite cloud cover,
   temperatures continue to warm into the low/mid 70s F and cumulus are
   beginning to deepen along the dryline. Given the forcing for ascent,
   initiation of stronger storms within the next 2-3 hours appears
   reasonable and is supported by most recent CAM guidance.

   Strong effective shear across the surface boundaries should support
   at least initially discrete storms. Strong forcing aloft may promote
   some areas of quicker upscale growth into line segments. Mid-level
   lapse rates advecting into the region will support large/very large
   hail. Low-level southeasterly winds will promote large low-level
   hodographs (already evident on the KMPX VAD). Tornadoes, some
   potentially strong, will be possible. The tornado risk will likely
   be greater with southeastward extent on account of the broader warm
   sector. Scattered severe gusts are also expected given convective
   transport of strong low-level flow to the surface.

   The timing of development remains the biggest uncertainty along with
   the relatively narrow zone of tornado risk in Minnesota. One ore
   more watches are likely early this afternoon.

   ..Wendt/Mosier.. 05/15/2025

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

   ATTN...WFO...DLH...ARX...MPX...FGF...

   LAT...LON   44109429 45039564 45879603 46339554 46449406 45999278
               45559214 44569190 43879237 43579286 44109429 

   MOST PROBABLE PEAK TORNADO INTENSITY...100-130 MPH
   MOST PROBABLE PEAK WIND GUST...55-70 MPH
   MOST PROBABLE PEAK HAIL SIZE...2.00-3.50 IN