Mesoscale Discussion 0640
   NWS Storm Prediction Center Norman OK
   0601 PM CDT Tue May 19 2020

   Areas affected...northern Colorado into southeast Wyoming and
   western Nebraska

   Concerning...Severe potential...Watch unlikely 

   Valid 192301Z - 200100Z

   Probability of Watch Issuance...20 percent

   SUMMARY...Developing storms in northeast Colorado will pose an
   isolated risk for severe hail and wind as they move into southeast
   Wyoming and western Nebraska. This threat will persist for the next
   few hours.

   DISCUSSION...Convective initiation is well underway across northern
   to northeast CO as storms form off of a lee trough/dryline and off
   the higher terrain. Stronger effective bulk wind shear (on the order
   of 40-50 knots) coupled with sufficient MLCAPE between 500-1000 J/kg
   should allow at least a storm or two to persist over the coming
   hours. Favorable deep layer shear as well as steep 8-9 C/km
   low-level lapse rates will support a threat for severe hail and wind
   as these storms move into southeast WY and the NE Panhandle. Modest
   low-level moisture advection ongoing across the WY/NE/CO tri-state
   area may aid in storm maintenance for an hour or so after sunset,
   but increasing inhibition due to the loss of daytime heating will
   diminish the severe threat heading into the overnight hours. Due to
   the isolated nature of the threat, a watch is not likely.

   ..Moore/Thompson.. 05/19/2020

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

   ATTN...WFO...LBF...BOU...CYS...

   LAT...LON   40520562 41130544 42040487 42400379 42030268 41390231
               40610259 40330344 40130432 40280490 40520562