Mesoscale Discussion 1877
   NWS Storm Prediction Center Norman OK
   0739 AM CDT Wed Oct 20 2021

   Areas affected...southwest MN into northwest IA

   Concerning...Severe potential...Watch unlikely 

   Valid 201239Z - 201415Z

   Probability of Watch Issuance...5 percent

   SUMMARY...Isolated strong thunderstorms may produce marginally
   severe hail this morning.

   DISCUSSION...Widely scattered elevated thunderstorms are ongoing
   this morning near a surface low over western IA/MN in an area of low
   level warm advection ahead of an upper trough and surface cold
   front. While instability will remain weak across the region given a
   cool surface temperatures and modest boundary-layer moisture, steep
   midlevel lapse rates greater than 7.5 C/km are in place over the
   region amid favorable effective shear. This should continue to
   support briefly organized clusters/cells this morning. The strongest
   cells may produce isolated hail stones up to 1 inch in diameter. The
   overall severe threat is expected to remain limited and a watch is
   not expected.

   ..Leitman/Guyer.. 10/20/2021

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

   ATTN...WFO...MPX...DMX...FSD...

   LAT...LON   44139648 44199618 44159500 43909437 43479393 43049388
               42669401 42409421 42319448 42319533 42549630 42649661
               43449664 43909662 44139648