Mesoscale Discussion 0832 NWS Storm Prediction Center Norman OK 0129 PM CDT Sun May 19 2024 Areas affected...Southeast Colorado into southwest Kansas and northwest Oklahoma Concerning...Severe potential...Severe Thunderstorm Watch likely Valid 191829Z - 192030Z Probability of Watch Issuance...95 percent SUMMARY...Observational trends suggest that storm initiation is probable within the next couple of hours in southeast Colorado/southwest Kansas. Development along the dryline farther east is less certain, but possible. Very-large hail, widespread severe wind gusts, and tornado or two are expected. A severe thunderstorm watch is likely this afternoon. DISCUSSION...Cumulus development has been steadily increasing along the Raton Mesa over the past couple of hours. While initial towers have not been sustained, the continued approach of a shortwave perturbation --now in the Four Corners vicinity per water vapor imagery--should aid in the deepening of these cumulus and eventually storm initiation somewhere in southeast Colorado into far western Kansas. Early convection will likely be present within a dry/well-mixed environment and be capable of strong to marginally severe wind gusts and perhaps hail. As this activity moves farther into Kansas, dewpoints now in the low 60s F should support rapid intensification. Effective shear 40-50 kts will promote supercells. The longevity of supercells is a bit uncertain. Should storms initiate on the dryline itself, they would be likely to remain supercellular longer. Activity approaching from the southwest would be more outflow dominant early in its life cycle, which could lead to a shorter duration of discrete mode as it encounters greater moisture. All that said, large to very large hail will be possible with any supercell. The tornado threat is not as clear given somewhat weak low-level winds that will increase after the storm mode will likely be more linear. Supercells in this strongly buoyant environment could still produce a tornado or two. With time, the expectation is for some amount of upscale growth to occur with an increase in severe wind gust potential. Some of these gusts could reach 75-90 mph. Farther south into northwest Oklahoma, timing of initiation is likely to be later than farther north given less influence of the shortwave and stronger capping. However, storms are more likely to be discrete and surface winds into western Oklahoma may remain more backed. In addition to the very-large hail and severe wind gust threat, tornadoes would be more probable in this mesoscale corridor. ..Wendt/Hart.. 05/19/2024 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...ICT...OUN...DDC...GLD...AMA...PUB... LAT...LON 37100193 37750235 38490247 38780223 38830145 38700018 38589922 38309882 37579851 37089858 35519932 35509997 35650028 37100193