MD 1836 CONCERNING SEVERE POTENTIAL…WATCH POSSIBLE FOR PORTIONS OF SOUTHERN SOUTH DAKOTA
Mesoscale Discussion 1836 NWS Storm Prediction Center Norman OK 0434 PM CDT Tue Jul 29 2025 Areas affected...portions of southern South Dakota Concerning...Severe potential...Watch possible Valid 292134Z - 292230Z Probability of Watch Issuance...60 percent SUMMARY...Severe gusts may accompany a mature MCS over the next few hours. Conditions are being monitored for the need of a Severe Thunderstorm Watch issuance. DISCUSSION...An eastward-propagating, cold-pool-driven MCS is in progress across southern SD, and is advancing into a highly unstable airmass, characterized by 3000+ J/kg MLCAPE, driven by 8 C/km lapse rates atop 70s F surface dewpoints. Vertical wind shear is not overly strong in proximity to this MCS, with only 20-30 kts of effective bulk shear in place, which is parallel to the MCS line orientation. Nonetheless, the strong to extreme instability and eroding MLCINH in advance of the MCS should compensate for any negative factors involving shear MCS intensity to support at least some organized threat for severe gusts. In addition, the more mixed boundary layer in southeast SD will support higher DCAPE downstream, which may further augment the severe wind potential. Evolution of the MCS will be monitored for the need of a Severe Thunderstorm Watch issuance. ..Squitieri/Mosier.. 07/29/2025 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...FSD...OAX...ABR...LBF...UNR... LAT...LON 43670070 44119993 44239878 43899676 43539608 43059615 42789659 42729747 42759819 42879884 43129963 43330023 43670070 MOST PROBABLE PEAK WIND GUST...65-80 MPH