Mesoscale Discussion 1779 NWS Storm Prediction Center Norman OK 0855 PM CDT Wed Jul 31 2024 Areas affected...Far Southeast South Dakota...Northern Iowa...Far Southern Minnesota...Far Southwest Wisconsin Concerning...Severe Thunderstorm Watch 585...586... Valid 010155Z - 010400Z The severe weather threat for Severe Thunderstorm Watch 585, 586 continues. SUMMARY...A severe threat is likely to continue across WW 585 and WW 586 over the next few hours, and may expand to areas south of the watches. If this occurs, a new watch may be considered. DISCUSSION...The latest mosaic radar imagery shows an MCS from eastern South Dakota into southwest Minnesota, with additional storms located in southeast Minnesota. Associated with the MCS, scattered severe storms are ongoing, mainly to the north of Sioux Falls. A pocket of extreme instability is located near Sioux Falls, where the RAP is analyzing MLCAPE in the 4000 to 5000 J/kg range. The storms are located along an east-to-west instability gradient, with surface dewpoints in the 70s F from the gradient southward. Short-term model forecasts suggest that storm coverage will gradually increase southward into the moist airmass over the next 2 to 3 hours. In addition to the moisture and instability, RAP analysis has moderate deep-layer shear and steep mid-level lapse rates in place. This will support continued organized storm development, with a threat for large hail and severe wind gusts. As the large cluster in eastern South Dakota moves east-southeastward across southern Minnesota and northern Iowa, cold pool development will be possible. Under this scenario, the potential for severe wind gusts would increase. ..Broyles.. 08/01/2024 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...MKX...ARX...MPX...DMX...FSD... LAT...LON 43769040 44019114 44189221 44429413 44499558 44459662 44259706 44019740 43629752 43229733 42959690 42709612 42629496 42819134 43149021 43459002 43769040
Storm Prediction Center Mesoscale Discussion 1779
31
Jul