Mesoscale Discussion 1253
   NWS Storm Prediction Center Norman OK
   0604 PM CDT Fri Jul 17 2020

   Areas affected...much of North Dakota and northwestern Minnesota

   Concerning...Severe Thunderstorm Watch 379...

   Valid 172304Z - 180100Z

   The severe weather threat for Severe Thunderstorm Watch 379
   continues.

   SUMMARY...The severe threat continues across WW 379.  Storms
   increasing in southwestern portions of the WW will pose a risk for
   wind, hail, and isolated tornadoes over the next few hours.

   DISCUSSION...An ongoing, mature MCS has evolved across northern
   portions of the WW this afternoon.  The leading edge of this MCS was
   demarcated by a stout outflow boundary located from near/just south
   of GFK westward to near N60.  A surface trough extended south of N60
   to near Y22.  South and east of these boundaries, steep mid-level
   lapse rates and 70s F dewpoints were contributing to strong to
   extreme instability, and the influence of a subtle shortwave trough
   over Wyoming on the western edge of this pool of instability was
   contributing to new convective development along the surface trough.
   Over time, models (including CAMs/WoF and to a lesser extent
   coarser-grid operational guidance) indicate that these storms will
   grow upscale into forward-propagating linear segments and clusters
   that will pose a risk for large hail, damaging (perhaps significant)
   wind gusts, and a tornado or two.  WW 380 has been issued south and
   east of the WW 379 to account for this potential scenario.

   North of the outflow, convective towers continue to deepen southeast
   of the Minot vicinity.  Given steep mid-level lapse rates and
   appreciable cloud-bearing shear in the region, large hail is
   probable despite being rooted above the boundary layer. A couple of
   storms have developed appreciable mid-level rotational signatures,
   with should also increase the large hail risk and may contribute to
   isolated severe wind gusts.  This threat should continue for at
   least a couple more hours.  Pending convective trends, temporal
   extensions of WW 379 may be needed beyond the scheduled 01Z
   expiration.

   ..Cook/Guyer.. 07/17/2020

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

   ATTN...WFO...FGF...ABR...BIS...UNR...

   LAT...LON   48950191 49099867 49069587 48729519 47689533 47399629
               47369785 46839896 46049980 45760116 45680263 45920334
               46970329 48470252 48950191