Mesoscale Discussion 1647
   NWS Storm Prediction Center Norman OK
   1006 AM CDT Mon Aug 30 2021

   Areas affected...central and southern North Dakota

   Concerning...Severe potential...Watch possible 

   Valid 301506Z - 301730Z

   Probability of Watch Issuance...40 percent

   SUMMARY...Initially elevated storms are expected to persist and may
   increase in coverage today, with a threat of hail. While a watch is
   not expected in the near term, the threat of damaging hail will
   increase by late afternoon across southern North Dakota into South
   Dakota.

   DISCUSSION...Visible satellite imagery and radar show elevated
   convection initiating across central ND, in a region of warm
   advection. Model forecast sounding show vastly differing instability
   profiles, suggesting some uncertainty regarding boundary-layer
   moisture quality. However, steep lapse rates aloft as well as
   effective shear around 40 kt will favor hail.

   Heating along with modest moisture advection will eventually result
   in strong, surface-based instability across SD and southwestern ND,
   with a transition from elevated to surface-based effective parcels
   after about 22Z. Veering winds with height will favor
   rightward-propagating supercells capable of damaging hail. A few
   damaging wind gusts will also be possible as storm coverage
   increases through early evening.

   ..Jewell/Grams.. 08/30/2021

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

   ATTN...WFO...BIS...

   LAT...LON   46300054 46750146 47070206 47310221 47580208 47680142
               47610020 47279948 46709905 46359918 46239959 46199986
               46300054