Storm Prediction Center Mesoscale Discussion 1899

   Mesoscale Discussion 1899
   NWS Storm Prediction Center Norman OK
   0112 PM CDT Wed Aug 14 2024

   Areas affected...much of Wyoming

   Concerning...Severe potential...Watch unlikely 

   Valid 141812Z - 142045Z

   Probability of Watch Issuance...5 percent

   SUMMARY...Widely scattered strong storms, some with small to
   marginally severe hail, appear likely to continue to develop with
   increasing potential to produce localized severe surface gusts
   through 3-5 PM MDT.

   DISCUSSION...A significant upper-level trough is in the process of
   slowly progressing east of the northern Intermountain Region into
   northern Rockies.  Beneath the mid-level cold core of this feature,
   large-scale ascent and destabilization are contributing to an area
   of sustained convective development and embedded thunderstorms, with
   additional scattered thunderstorms initiating in advance of this
   cluster across the Absaroka, Wind River and Bighorn Ranges of
   Wyoming.  

   Across downstream lower elevations, boundary-layer warming and
   mixing are well underway in response to insolation, with surface
   temperature/dew point spreads already exceeding 30 F at some
   locations.  With further heating and cooling aloft, mixed-layer CAPE
   in excess of 500 J/kg (and perhaps locally up to around 1000 J/kg)
   is forecast to continue to develop through mid/late afternoon.  As
   this occurs, scattered thunderstorm development is likely to be
   maintained and intensify. 

   Beneath modestly sheared mean westerly flow, including speeds on the
   order of 25-30 kt in the cloud-bearing layer, stronger storms may be
   accompanied by small to, perhaps, marginally severe hail.  And
   negative buoyancy, aided by melting and evaporative cooling, in
   downdrafts may increasingly support localized strong to severe
   surface gusts through 21-23Z.

   ..Kerr/Thompson.. 08/14/2024

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

   ATTN...WFO...UNR...CYS...RIW...SLC...PIH...

   LAT...LON   44560819 44220616 43580501 41820495 41250589 41200812
               41111017 42901021 43311103 43911109 44401005 44560819