Mesoscale Discussion 1226
   NWS Storm Prediction Center Norman OK
   0349 PM CDT Sun Jun 19 2022

   Areas affected...Western ND and far northwest SD

   Concerning...Severe potential...Severe Thunderstorm Watch likely 

   Valid 192049Z - 192315Z

   Probability of Watch Issuance...80 percent

   SUMMARY...The risk of large hail and locally severe gusts will
   increase across western ND and far northwest SD between 23-01Z. A
   watch will likely be needed at some point downstream of Severe
   Thunderstorm Watch 391.

   DISCUSSION...In response to increasing large-scale ascent at the
   nose of a midlevel jet streak impinging on the northern High Plains
   (per water vapor imagery), surface observations depict a
   consolidating surface low near Mountrail County, ND. While RAP
   forecast soundings show lingering convective inhibition in the
   vicinity of the surface low, continued diurnal heating of the
   sheltered boundary-layer air (upper 60s/lower 70s dewpoints) could
   support isolated convective initiation over northwest ND during the
   next few hours. Northerly surface winds beneath strong/deep
   south-southwesterly flow will result in an elongated hodograph
   supportive of supercell structures and an attendant risk of large
   hail and severe gusts. However, large uncertainty remains owing to
   the lingering convective inhibition and cloud coverage.

   Later into the evening hours, current thinking is that supercells
   and bowing segments capable of large hail and damaging winds will
   spread northeastward from parts of eastern MT into western ND and
   far northwest SD. Upper 60s/lower 70s dewpoints and continued
   diurnal destabilization should support the maintenance of this
   activity given 40-50 kt of effective shear. Ultimately, a watch will
   eventually be needed for parts of the area (downstream of Severe
   Thunderstorm Watch 391), though timing remains unclear owing to
   lingering uncertainty regarding convective evolution north of the
   surface low.

   ..Weinman/Grams.. 06/19/2022

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

   ATTN...WFO...BIS...UNR...GGW...

   LAT...LON   45430249 45140349 45150396 45880398 46680402 47990411
               48530389 48900345 49080279 49140179 49010102 48110104
               46360196 45430249