Mesoscale Discussion 1063
   NWS Storm Prediction Center Norman OK
   0838 PM CDT Tue Jun 30 2020

   Areas affected...Eastern North Dakota and northeast South Dakota

   Concerning...Severe Thunderstorm Watch 319...

   Valid 010138Z - 010245Z

   CORRECTED FOR GRAPHIC

   The severe weather threat for Severe Thunderstorm Watch 319
   continues.

   SUMMARY...A large hail and damaging wind threat will persist through
   the evening across the eastern Dakotas.

   DISCUSSION...Storms have formed along the cold front from southern
   North Dakota into northern South Dakota. Convection has not been
   that strong thus far, likely due to the weak effective shear and the
   warm air around 3 km. The 00Z ABR sounding is a good proximity
   sounding for the environment along this line. This RAOB shows
   extreme instability (~3800 J/kg J/kg) and effective shear around 10
   knots. In addition, CAPE is very small (35 J/kg in the lowest 3km
   and likely responsible for the lack of explosive updraft development
   despite the extreme instability. Additionally, the storms which have
   formed in the confluence zone near Aberdeen, SD have also struggled
   thus far.

   While there is still a chance for strong to severe storms, the
   window is shrinking as the boundary layer rapidly cools in the next
   2 hours.

   The best chance for severe storms will likely be in eastern North
   Dakota for the next several hours. Flow is somewhat stronger in this
   region based on the 00Z KBIS RAOB and the KMVX VWP. This is likely
   why storms have shown slightly better organization. In addition, the
   cold front is oriented more orthogonal to the low-level shear in
   north Dakota, and thus updrafts have been able to stay better rooted
   along the boundary.

   ..Bentley.. 07/01/2020

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

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

   LAT...LON   44709832 45619874 47459965 48310013 48730017 49039965
               49009787 48969732 47719674 45579665 44589704 44709832