Mesoscale Discussion 0990
   NWS Storm Prediction Center Norman OK
   0702 PM CDT Thu Jun 17 2021

   Areas affected...South-Central/Southeast MN...West-Central
   WI...North-Central/Northeast IA

   Concerning...Severe Thunderstorm Watch 276...

   Valid 180002Z - 180130Z

   The severe weather threat for Severe Thunderstorm Watch 276
   continues.

   SUMMARY...The threat for severe thunderstorms continues across much
   of the Upper MS Valley. Large hail is the primary threat, with some
   damaging wind gusts possible as well. Parts of
   south-central/southeast MN are being monitored for additional watch
   issuance.

   DISCUSSION...Recent surface analysis places the cold front from
   about 10 miles east-southeast of EAU southwestward through
   south-central MN and far northwest IA. A corridor of slightly higher
   dewpoints exists along this frontal boundary, with mid 60s dewpoints
   extending into far west-central WI. A few storms have developed
   along this front in far west-central WI, where surface temperatures
   were a few degrees higher, which resulted in less convective
   inhibition. Environment near these storms supports strong updrafts
   and the potential for quick upscale growth on storm outflow. Severe
   threat with these storms will likely persist into more of central
   WI.

   Farther west (across southwest MN), a few storms have recently
   developed, likely as a result of persistent warm air advection
   across the region. Character of the reflectivity also suggests thee
   storms are elevated. Steep mid-level lapse rates and resulting
   strong buoyancy could result in a few updrafts capable of producing
   large hail. Some additional development appears possible across this
   area with new echos now beginning to appear. Overall storm coverage
   remains uncertain given the warm low to mid-level temperatures and
   resulting convective inhibition. However, persistent isentropic
   ascent coupled with the approach of a subtle vorticity maximum and
   southward pushing 850mb front suggest potential for additional
   storms.

   ..Mosier/Guyer.. 06/18/2021

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

   ATTN...WFO...GRB...MKX...ARX...MPX...DMX...

   LAT...LON   44449451 44889213 45038995 44738908 44158899 43389005
               43209213 43249378 44449451