Mesoscale Discussion 1133
   NWS Storm Prediction Center Norman OK
   0621 PM CDT Tue Jul 07 2020

   Areas affected...eastern Montana

   Concerning...Severe Thunderstorm Watch 338...

   Valid 072321Z - 080045Z

   CORRECTED FOR MD GRAPHIC TEXT

   The severe weather threat for Severe Thunderstorm Watch 338
   continues.

   SUMMARY...The likelihood of widespread damaging wind including
   potential for several significant straight line wind gusts will
   persist through 01Z as the squall line moves through the remainder
   of eastern Montana.

   DISCUSSION...A line of severe storms from just west of Glasgow
   southward to just east of Billings is moving east at 50-55 kt. The
   downstream atmosphere remains moderately to strongly unstable with
   2500-3000 J/kg MLCAPE and steep low to mid-level lapse rates along
   with 40-45 kt effective bulk shear. This environment will continue
   to support organized storm structures including bowing segments and
   embedded supercells capable of widespread damaging wind, hail and a
   couple of tornadoes. The Glasgow VWP shows east-southeasterly
   low-level winds around 30 kt veering to southerly above 1 km.
   Further strengthening of the low-level jet is expected into the
   evening and will promote strong forcing/convergence needed to
   maintain a forward-propagating severe MCS into the evening despite
   an increase in convective inhibition. Storms will approach the
   eastern bound of WW 338 by 0130Z, and a downstream WW will likely be
   needed for western North Dakota by 0030-01Z.

   ..Dial/Thompson.. 07/07/2020

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

   ATTN...WFO...BIS...BYZ...GGW...

   LAT...LON   46980718 47960709 48670729 48910585 48580459 47190395
               46100466 45700564 45850745 46980718