ZCZC SPCSWOMCD ALL ACUS11 KWNS 291846 SPC MCD 291846 NEZ000-KSZ000-SDZ000-COZ000-WYZ000-291945- Mesoscale Discussion 1194 NWS Storm Prediction Center Norman OK 0146 PM CDT Sun Jul 29 2018 Areas affected...southeast WY...NE Panhandle...northeast and east-central CO Concerning...Severe potential...Tornado Watch likely Valid 291846Z - 291945Z Probability of Watch Issuance...95 percent SUMMARY...A tornado watch will likely be needed by 2-3pm MDT for expected severe thunderstorm development this afternoon and an associated risk for tornadoes, from southeast WY into northeast CO. A severe thunderstorm watch will likely be issued farther east from the Black Hills vicinity southward into northwest KS. DISCUSSION...Visible satellite imagery shows an agitated cumulus field over extreme southeast WY located downstream and to the southeast of glaciating convection 35 mi south of DGW. Low-level upslope flow is maintaining a moist fetch into the central High Plains and the boundary layer will continue to warm through the middle to upper 70s by mid afternoon. KCYS VAD data shows a strongly veering hodograph around 1-1.5 km ARL with flow increasing with height through 5km. Forecast soundings show west-northwesterly flow increasing from 50kt at 500mb to 90kt at 250mb. As low-level lapse rates steepen and additional heating occurs, convective inhibition will erode and isolated to scattered thunderstorms will develop and intensify. Supercells are likely to evolve from the most intense updrafts with splitting supercells expected given the straight-line hodographs depicted in forecast soundings. Large to very large hail will likely occur with the stronger and more persistent/rotating updrafts. A tornado risk will tend to be confined to southeast WY and northeast CO where RH in the boundary layer will not support as much of a destructive tendency for cold/hostile RFDs. The tornado risk is conditional on right-moving supercells interacting and favorably augmenting the near-storm environment later this afternoon and early evening. Farther northeast near the Black Hills and the western part of the NE Sandhills, less favorable buoyancy and low-level shear will tend to promote a hail/wind risk with the stronger storms. ..Smith/Grams.. 07/29/2018 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...LBF...UNR...GLD...PUB...BOU...CYS... LAT...LON 41330570 42180556 43090471 44010311 43800221 43340174 39580091 38710208 38650392 39220502 41330570 NNNN