Mesoscale Discussion 1406
   NWS Storm Prediction Center Norman OK
   0127 PM CDT Wed Aug 05 2020

   Areas affected...northern/northeastern Colorado...southeastern
   Wyoming...and western Nebraska

   Concerning...Severe potential...Watch possible 

   Valid 051827Z - 052030Z

   Probability of Watch Issuance...40 percent

   SUMMARY...Convection over the higher terrain of Colorado/Wyoming
   will migrate eastward/southeastward and deepen through the
   afternoon, posing a hail/wind threat in areas downstream.  A WW will
   be considered later this afternoon.

   DISCUSSION...Deepening convection was noted across higher terrain in
   north-central Colorado and south-central Wyoming in the past hour or
   so.  These storms are in a steep-lapse-rate environment, with 8-9
   deg C/km and boundary layer moisture contributing to weak to
   moderate  instability (2000-3500 J/kg MUCAPE) in areas immediately
   downstream of initiating convection.  The combination of weak
   low-level upslope flow beneath 40 knot westerly mid/upper flow will
   allow for developing convection to migrate eastward through the I-25
   corridor and into lower elevations over the course of the afternoon,
   with initial supercellular structures and clusters potentially
   capable of large (perhaps significant) hail and damaging wind gusts.
    A tornado can also not be completely ruled out despite high cloud
   bases.  Eventually, one or two linear segments will evolve from
   initial convection while moving toward the CO/KS/NE border regions
   toward evening.

   Pending convective coverage, a Severe Thunderstorm Watch may need to
   be coordinated with affected offices in the 19-21Z time frame. 
   Trends are being monitored.

   ..Cook/Kerr.. 08/05/2020

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

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

   LAT...LON   42570628 42650501 42260365 41970272 41630220 41310193
               40680184 39660207 38830235 38160331 38020426 38250517
               39020602 39890639 40880638 42570628