ZCZC SPCSWOMCD ALL ACUS11 KWNS 132148 SPC MCD 132148 KSZ000-NEZ000-COZ000-132345- Mesoscale Discussion 0606 NWS Storm Prediction Center Norman OK 0448 PM CDT Thu May 13 2021 Areas affected...southwest NE...far northwest KS Concerning...Severe potential...Watch unlikely Valid 132148Z - 132345Z Probability of Watch Issuance...20 percent SUMMARY...An isolated risk for large hail and localized severe gusts may accompany the stronger storms that manage to develop late this afternoon into the evening. Storm coverage and severe-producing storms will likely remain too isolated to warrant a severe thunderstorm watch issuance. DISCUSSION...Visible satellite imagery late this afternoon shows a cluster of strong to severe storms over the western part of the NE Sandhills and another discrete storm near the NE/CO/KS border. Ample heating has occurred downstream/southeast of the ongoing activity (as of 2140 UTC) with mid 70s deg F temperatures. Forecast soundings show rather cool mid-level temperatures (-17 deg C at 500 mb), which is resulting in 500-750 J/kg MLCAPE despite relatively marginal boundary layer moisture (mid-upper 40s deg F dewpoints). As a mid-level shortwave trough over the northern High Plains/Black Hills vicinity continues to approach the region this evening, support for additional storms developing or maintaining their vigor into the early evening hours seems plausible. The strong veering flow with height increasing to 80 kt at 250 mb will aid in storm venting and possibly hail production considering the long, straight hodographs and cool mid-level temperatures. Given the current forecast expectation for limited storm development south of the NE Sandhills thunderstorm cluster, a severe thunderstorm watch will likely not be needed farther south over northwest KS and adjacent parts of NE this evening. ..Smith/Grams.. 05/13/2021 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...GID...LBF...GLD... LAT...LON 40330216 40610135 40499997 39509995 39350084 39600189 40330216 NNNN