Storm Prediction Center Mesoscale Discussion 879

   Mesoscale Discussion 0879
   NWS Storm Prediction Center Norman OK
   0509 PM CDT Tue May 21 2024

   Areas affected...Central Iowa into northeast Iowa and far southwest
   Wisconsin.

   Concerning...Tornado Watch 277...

   Valid 212209Z - 212345Z

   The severe weather threat for Tornado Watch 277 continues.

   SUMMARY...Intense to potentially violent tornado threat across
   northeast Iowa and into southwest Wisconsin over the next 2 hours

   DISCUSSION...The supercell which formed the intense to potentially
   violent tornado which impacted Greenfield and other portions of
   southwest Iowa this afternoon has re-intensified after storm
   mergers. This storm and another strong supercell to its south are
   moving into an increasingly favorable tornadic environment with a
   STP of 5 to 6 (per SPC mesoanalysis). The backed surface winds and
   vorticity rich environment in the wake of the morning convection
   will provide ample low-level vorticity for a sustained tornado
   threat into the early evening. One or more long-track, potentially
   violent tornadoes are possible in this corridor over the next 90 to
   120 minutes.

   ..Bentley/Thompson.. 05/21/2024

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

   ATTN...WFO...DVN...ARX...DMX...

   LAT...LON   43319094 43149080 42899079 42509117 41569273 41459346
               42039360 42679316 43289233 43499174 43489133 43499120
               43319094