Mesoscale Discussion 0878
   NWS Storm Prediction Center Norman OK
   0918 PM CDT Sun Jun 07 2020

   Areas affected...South Dakota...Northern Nebraska

   Concerning...Severe Thunderstorm Watch 268...

   Valid 080218Z - 080315Z

   The severe weather threat for Severe Thunderstorm Watch 268
   continues.

   SUMMARY...Severe threat will continue beyond 03z across much of
   ww268. Watch extension, or new watch, may be warranted.

   DISCUSSION...Surface boundary has moved little over the last few
   hours despite considerable amount of convection along the frontal
   corridor. Robust updrafts, with hail cores, remain embedded along an
   axis from Cherry County NE to Brown County SD in the northern
   portion of the watch. There is increasing concern that this activity
   will not weaken appreciably before 03z as primary mid-level vort is
   currently lifting north-northeast across southern MT, just north of
   SHR, and negligible height changes are forecast across the
   northern/central Plains tonight. With LLJ expected to increase
   across eastern SD over the next few hours it appears this corridor
   of convection will persist for several more hours. Watch extension,
   or new watch may be warranted.

   ..Darrow.. 06/08/2020

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

   ATTN...WFO...FSD...ABR...LBF...UNR...CYS...

   LAT...LON   42070274 45929994 45909744 42070041 42070274