ZCZC SPCSWOMCD ALL ACUS11 KWNS 251851 SPC MCD 251851 SDZ000-NEZ000-WYZ000-252045- Mesoscale Discussion 0512 NWS Storm Prediction Center Norman OK 0151 PM CDT Thu Apr 25 2024 Areas affected...Southeast Wyoming into South Dakota and northwest Nebraska Concerning...Severe potential...Watch possible Valid 251851Z - 252045Z Probability of Watch Issuance...60 percent SUMMARY...Thunderstorms are expected to gradually intensify through the afternoon hours across parts of southeast Wyoming, western South Dakota, and northwest Nebraska. This activity will primarily pose a severe hail risk, though a few severe gusts are also possible. DISCUSSION...Over the past 1-2 hours, high-based convection developing off the higher terrain of central WY, along with additional convection along a deepening surface trough, has migrated into a narrow plume of returning moisture noted in surface observations (dewpoints in the low to mid 50s). Steep lapse rates between 8-9 C/km noted in 12 UTC soundings remain entrenched over the region with upper-level ascent increasing with the approach of synoptic wave from the southwest. This combination of improving moisture and steep lapse rates is supporting MLCAPE values upwards of 1000 J/kg over a region with increasing ascent. Consequently, thunderstorm coverage and intensity is forecast to increase through the afternoon. While stronger mid-level flow is displaced to the south, elongated hodographs featuring 30 knot winds near the 6 km level should support organization of semi-discrete cells and thunderstorm clusters with an attendant threat for large hail (most likely between 0.75 to 1.5 inches in diameter). Additionally, 20-30 F dewpoint depressions indicate steep low-level lapse rates that should support the potential for a few severe gusts - especially if a more organized cluster with a consolidated cold pool can become established. ..Moore/Hart.. 04/25/2024 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...LBF...UNR...CYS... LAT...LON 41400497 42890500 43730424 45270256 45320203 44820147 44430131 43640208 42700284 41700349 41140400 41100456 41400497 NNNN