ZCZC SPCSWOMCD ALL ACUS11 KWNS 161940 SPC MCD 161940 KSZ000-NEZ000-COZ000-WYZ000-162045- Mesoscale Discussion 1760 NWS Storm Prediction Center Norman OK 0240 PM CDT Fri Aug 16 2019 Areas affected...southeastern Wyoming and eastern Colorado Concerning...Severe potential...Severe Thunderstorm Watch likely Valid 161940Z - 162045Z Probability of Watch Issuance...80 percent SUMMARY...Thunderstorms are expected to develop over the high terrain and along the surface pressure trough this afternoon and evening, posing a threat for large hail and damaging winds. A severe thunderstorm watch will likely be needed by 21Z. DISCUSSION...Low-level stratus clouds finally eroded this morning over northeastern Colorado and southeastern Wyoming allowing for full insolation. As a result, destabilization will continue through the afternoon in the presence of adequate low-level moisture and very steep midlevel lapse rates (90th percentile value in 12Z DNR sounding). Weak upslope low-level flow (east of the surface pressure trough) will contribute to effective deep-layer shear over 40 knots, supportive of supercells capable of producing large hail, damaging winds, and perhaps a tornado. A severe thunderstorm watch will likely be needed by 21Z. Considerable uncertainty remains regarding the eventual convective evolution from the initial expected supercell mode. Significant convective inhibition around 700 mb (associated with the stout EML) exists over the plains, so it is unclear whether storms will be able to organize and grow upscale with eastward extent. An increasing low-level jet this evening will provide support for ongoing storms and encourage new storm development, especially across western/central Kansas. The threat for organized damaging winds would increase if this type of convective evolution materializes. ..Jirak/Grams.. 08/16/2019 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...LBF...DDC...GLD...PUB...BOU...CYS... LAT...LON 39610528 40340544 41460560 42330559 42670519 42650446 42430359 41810288 40780213 40010182 39530159 38610154 38200169 37740231 37670279 37770351 38280426 39610528 NNNN