ZCZC SPCSWOMCD ALL ACUS11 KWNS 081751 SPC MCD 081751 KSZ000-NEZ000-COZ000-WYZ000-081945- Mesoscale Discussion 1201 NWS Storm Prediction Center Norman OK 1251 PM CDT Sat Jun 08 2024 Areas affected...Southeast WY...southern NE Panhandle...CO Front Range and eastern plains...southwest NE...northwest KS Concerning...Severe potential...Severe Thunderstorm Watch likely Valid 081751Z - 081945Z Probability of Watch Issuance...80 percent SUMMARY...Scattered thunderstorms are forecast to develop from west of Cheyenne, WY to the I-70 foothills vicinity west of Denver during the 18-19 UTC (12-1 pm MDT) period. The risk for mainly large hail will be the most prominent severe hazard as the activity emerges from the higher terrain into the High Plains. As storms mature with increasing cold pool coverage and additional storm mergers occur, the threat for severe gusts will quickly increase and become the more widespread hazard as the storms move well east of Denver into eastern CO and eventually into northwest KS/southwest NE by early evening. DISCUSSION...Midday satellite imagery shows a mid-level shortwave trough moving east from eastern UT into northwest CO/southern WY. Ahead of this feature, large-scale ascent will continue to increase in the areas downstream over the Front Range. Strong heating and orographic ascent of a seasonably moist airmass (17 UTC surface observations in the WY-CO I-25 corridor indicate 50s deg F dewpoints) will contribute to thunderstorms continuing to initiate during the next hour or so (between 18-19 UTC). Forecast soundings show buoyancy increasing to around 1500 J/kg near I-25, with 2000-2500 J/kg farther east near the CO/KS/NE tri-state border by late this afternoon. Ample deep-layer shear due to easterly low-level flow veering to westerly and increasing with height will strongly favor storm organization. The early convective cycle of the storms will likely feature a mix of supercells and multicells. The hail risk will be most prominent during this period in which storms have not transitioned to a more outflow-generating storm mode. Large to very large hail (peak diameter potentially in the 2 to 3 inches range) will be possible with these storms. The potential for severe gusts will quickly increase once cold pools become established and additional storm merging occurs. A linear cluster evolving into a forward-propagating squall line will probably occur later this afternoon into the evening. Severe gust intensity will correspondingly increase with potential peak wind speeds in eastern CO/northwestern KS in the 75-90 mph range. ..Smith/Gleason.. 06/08/2024 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...LBF...GLD...PUB...BOU...CYS... LAT...LON 41690495 41800410 41500345 40970239 40820164 40380123 39620114 38990127 38530203 38410279 38460401 39050499 39460533 39930539 40660538 41290523 41690495 NNNN