Mesoscale Discussion 1303
   NWS Storm Prediction Center Norman OK
   0212 PM CDT Tue Jul 21 2020

   Areas affected...southeast WY...parts of the NE Panhandle and
   eastern CO

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

   Valid 211912Z - 212045Z

   Probability of Watch Issuance...95 percent

   SUMMARY...Thunderstorms are expected to become severe by late
   afternoon from southeast WY into western CO and portions of the NE
   Panhandle. Damaging wind gusts and isolated large hail can be
   expected with storms through this evening.

   DISCUSSION...Widely scattered thunderstorms are developing via
   strong diurnal heating of higher terrain from southern/central CO
   into southern WY. Further east, strong inhibition is still in place
   across the eastern CO High Plains, but continued easterly upslope
   flow, heating and modest moisture transport should weaken capping
   sufficiently by late afternoon/early evening to sustain convection
   moving east/southeast off of higher terrain. Capping has already
   eroded further north over southeast WY where a broad CU field is
   noted in visible satellite imagery, and an isolated thunderstorm has
   already developed over Converse County. 

   As the boundary layer continues to destabilize, effective shear is
   forecast to increase to 35-45 kt, supporting organized, high-based
   supercells. Steep mid level lapse rates will favor occasional large
   hail. However, the main hazard with this convection is expected to
   be damaging wind gusts. A deeply mixed boundary layer with very
   steep low level lapse rates and inverted-v sub-cloud layer
   thermodynamic profiles indicate optimal conditions for strong
   outflow winds. A severe thunderstorm watch will likely be needed
   soon.

   ..Leitman/Hart.. 07/21/2020

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

   ATTN...WFO...LBF...GLD...PUB...BOU...CYS...

   LAT...LON   41590566 42480599 42860586 43160561 43180477 42960402
               41730287 40910244 40250229 39720230 38300276 37460335
               37280414 37570468 38120501 41590566