Mesoscale Discussion 0173
   NWS Storm Prediction Center Norman OK
   0501 PM CDT Fri Mar 14 2025

   Areas affected...eastern Nebraska...Iowa...southern
   Minnesota...southwestern Wisconsin...and northwestern Illinois

   Concerning...Severe Thunderstorm Watch 31...

   Valid 142201Z - 142330Z

   The severe weather threat for Severe Thunderstorm Watch 31
   continues.

   SUMMARY...Thunderstorms are moving rapidly northward across Iowa,
   where risk for strong/damaging wind gusts amd severe-caliber hail
   will continue.  New WW issuance will likely be required north of the
   existing watch, into southern Minnesota, and -- thereafter -- east
   of the watch into eastern Iowa/northwestern Illinois.

   DISCUSSION...Latest radar loop shows an arcing band of strong/severe
   storms extending eastward from eastern Nebraska into/across
   southwestern Iowa, and then southeastward and southward across
   Missouri.  The west-to-east portion of the band is moving quickly
   northward/north-northwestward, while the more north-south portion
   across Missouri is advancing rapidly northward/north-northeastward. 
   A second cluster of strong/rotating storms -- north of the
   west-to-east band -- is moving north-northwestward across
   west-central Iowa at this time.

   Greater low-level moisture (dewpoints in the 50s) exists across far
   southern Missouri and into Arkansas, and is spreading northward on
   strong southerly flow.  However, a dry, deeply mixed boundary layer
   (to around 700mb) is evident from central and northeastern Missouri
   northward, with modest CAPE above the mixed layer.  While
   severe-caliber hail remains possible locally -- particularly with
   the more isolated, west-central Iowa storms, the primary severe risk
   remains very strong/damaging wind gusts -- given both the intense,
   deep-layer wind field, and the sub-cloud dry air that will encourage
   evaporatively enhanced downdrafts.

   With the fast storm motion that is observed, severe risk will likely
   begin to spread north of the existing watch (into northern Iowa and
   eventually southern Minnesota) over the next hour or so.  Meanwhile,
   storms moving quickly north-northeastward toward/into northeastern
   Missouri will also begin affecting adjacent southwestern
   Iowa/northwestern Illinois -- i.e. the DVN CWA -- starting in the
   next hour or so.  New WW issuances will be considered in both of
   these surrounding areas.

   ..Goss.. 03/14/2025

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

   ATTN...WFO...LOT...ILX...MKX...LSX...DVN...ARX...MPX...DMX...
   EAX...FSD...OAX...GID...

   LAT...LON   40109740 41189767 42649683 43669568 44099397 43939069
               42518949 41388921 40178981 40109740