Storm Prediction Center Mesoscale Discussion 1588

   Mesoscale Discussion 1588
   NWS Storm Prediction Center Norman OK
   0412 AM CDT Mon Jul 07 2025

   Areas affected...far northeast Wyoming...far southeast Montana...and
   western South Dakota

   Concerning...Severe potential...Watch unlikely 

   Valid 070912Z - 071115Z

   Probability of Watch Issuance...20 percent

   SUMMARY...Thunderstorms should continue this morning. Hail and gusty
   winds may be possible with the strongest storms. Currently, a watch
   is not anticipated for this threat.

   DISCUSSION...Elevated thunderstorms are ongoing / redeveloping this
   morning across far northeast Wyoming and western South Dakota. These
   storms appear to be rooted between 850 and 700 millibars and are
   likely driven by modest warm-air advection within this layer per
   model forecast soundings across the region. 

   The overall environment is unstable with most-unstable CAPE between
   1000-1500 J/kg. However, effective-layer shear is quite variable
   across the area, with better shear to the north and to the south of
   the ongoing thunderstorms. That said, effective-layer shear between
   25-30 knots is sufficient to support strong multicells or even
   transient supercellular characteristics. Given the degree of
   instability and at least modest effective-layer shear, isolated hail
   and perhaps strong wind gusts cannot be ruled out with the stronger
   thunderstorm updrafts. However, widespread organized severe
   potential is not anticipated and thus a watch is not expected. 

   Some CAM-based guidance does indicate the potential for ongoing
   thunderstorms to eventually coalesce into a small organized MCS
   later this morning. Should evidence of this organization start to
   materialize, the potential for a watch later this morning would
   increase accordingly.

   ..Marsh/Bunting.. 07/07/2025

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

   ATTN...WFO...ABR...UNR...BYZ...

   LAT...LON   44090536 44530586 45040550 45350454 45630349 45580231
               45230132 44520099 43880102 43440139 43220220 43420333
               43710446 44090536 

   MOST PROBABLE PEAK WIND GUST...UP TO 60 MPH
   MOST PROBABLE PEAK HAIL SIZE...UP TO 1.25 IN