Storm Prediction Center Mesoscale Discussion 1634

   Mesoscale Discussion 1634
   NWS Storm Prediction Center Norman OK
   0303 PM CDT Thu Jul 16 2026

   Areas affected...portions of southwestern into central Montana

   Concerning...Severe potential...Watch possible 

   Valid 162003Z - 162130Z

   Probability of Watch Issuance...40 percent

   SUMMARY...The severe threat may continue to increase through the
   afternoon hours. Severe hail may occur with the stronger storms, and
   isolated severe gusts are also possible.

   DISCUSSION...MRMS mosaic radar imagery and NLDN lightning data
   depict convective initiation underway across the northern Rockies,
   with MRMS MESH data suggesting that storm cores are already
   beginning to produce hail (albeit sub-severe). 19Z mesoanalysis
   depict eroding MLCINH, with MLCAPE exceeding 1000 J/kg on a
   widespread basis given strong surface heating beneath 7.5+ C/km
   mid-level lapse rates. RAP forecast soundings also show elongated
   hodographs, contributing to 30-40 kts of effective bulk shear.
   Therefore, some storms may organize into at least transient
   supercells capable of producing severe hail. Given near 30 T/Td
   spreads, evaporative cooling may also support a couple of severe
   gusts.

   ..Squitieri/Guyer.. 07/16/2026

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

   ATTN...WFO...BYZ...TFX...MSO...

   LAT...LON   46280950 45440946 45220980 45071075 44901177 44881231
               44911284 45851369 47341382 48231361 48331239 47801080
               47321011 46280950 

   MOST PROBABLE PEAK WIND GUST...55-70 MPH
   MOST PROBABLE PEAK HAIL SIZE...1.00-1.75 IN