Mesoscale Discussion 1809
   NWS Storm Prediction Center Norman OK
   0507 PM CDT Thu Oct 07 2021

   Areas affected...Portions of the Great Basin

   Concerning...Severe potential...Watch unlikely 

   Valid 072207Z - 080000Z

   Probability of Watch Issuance...5 percent

   SUMMARY...A few strong to locally severe thunderstorms are possible
   through this evening across portions of the Great Basin. Isolated
   instances of gusty winds and near-severe hail are the primary severe
   threats. The spotty nature of any severe threat will likely preclude
   a severe weather watch.

   DISCUSSION...Radar imagery over the past hour or so shows widely
   scattered and mostly poorly disorganized multicell thunderstorms
   across portions of the Great Basin as a mid-level shortwave trough
   approaches the area. The strongest storm during this time has been
   located over Cassia County in southern Idaho, where periodic updraft
   organization has allowed this thunderstorm to remain near severe
   limits (MRMS MESH near 1 inch). Occasional
   strengthening/organization of nearby/new thunderstorm updrafts are
   possible over the next several hours due to effective bulk shear
   near 40 knots and modest instability (e.g., MLCAPE near 500 J/kg) --
   best overlap over southern/southeastern Idaho. Isolated instances of
   marginally severe hail and gusty winds will be possible with the
   strongest storms through mid/late evening before instability weakens
   further.

   Overall, the spotty nature of any severe threat should preclude a
   severe weather watch.

   ..Elliott/Thompson.. 10/07/2021

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

   ATTN...WFO...RIW...SLC...PIH...BOI...LKN...

   LAT...LON   41121610 41781565 42601456 43491205 43371062 43111016
               42440985 41741063 40911180 39841367 39931482 40261590
               40611638 41121610