Mesoscale Discussion 1620
   NWS Storm Prediction Center Norman OK
   0530 PM CDT Fri Aug 27 2021

   Areas affected...northeast IA

   Concerning...Tornado Watch 465...

   Valid 272230Z - 272330Z

   The severe weather threat for Tornado Watch 465 continues.

   SUMMARY...The severe threat in recently issued tornado watch #465
   will likely focus primarily in northeast IA during the next 1-2
   hours.  The risk for supercell-related hazards will include hail,
   severe gusts, and possibly a tornado.

   DISCUSSION...Visible-satellite imagery shows an outflow boundary
   situated west-east across far northeast IA into southwest WI. 
   Temperatures south of the boundary are in the low-mid 80s with mid
   70s dewpoints.  As a result, a very unstable airmass is located over
   the upper MS Valley early this evening.  It seems a messy supercell
   mode may persist for the next few hours due in part to 1) only weak
   forcing but 2) enlargement of the hodograph with a veer-back-veer
   wind profile---leading to precipitation seeding near updrafts.  RAP
   forecast soundings depict this relative limitation in the wind
   profile in the upper levels which is only partly observed by the La
   Crosse, WI 88D VAD data.

   ..Smith.. 08/27/2021

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

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

   LAT...LON   43219323 43479179 43279132 42959145 42849308 42989327
               43219323