Mesoscale Discussion 1729
Issued: · Valid: –
Summary
Severe thunderstorms capable of producing wind gusts between 80 and 100 mph are possible across south-central and southeast South Dakota this afternoon and evening.
Product Text
000 ACUS11 KWNS 251915 SWOMCD SPC MCD 251915 SDZ000-NEZ000-252045- Mesoscale Discussion 1729 NWS Storm Prediction Center Norman OK 0215 PM CDT Sat Jul 25 2026 Areas affected...south-central to southeast South Dakota Concerning...Severe potential...Watch likely Valid 251915Z - 252045Z Probability of Watch Issuance...95 percent SUMMARY...80-100 mph winds are possible this afternoon and evening from south-central to southeast South Dakota. A severe thunderstorm watch will be needed in the next 1 to 2 hours. DISCUSSION...A very hot environment is in place across South Dakota with temperatures of 105 to 110F across southwest and south-central South Dakota. The 18Z UNR RAOB shows nearly 2500 J/kg MLCAPE. This may be somewhat artificially inflated by the low-level dewpoint profile, but even after modifying this to something more realistic, MLCAPE near 2000 J/kg seems likely. This is significantly less than SPC mesoanalysis but is more congruent with current satellite and radar imagery which show what appears to be surface-based storm development within areas that currently indicate significant remaining inhibition from SPC mesoanalysis. These storms are developing on the leading edge of a mid-upper level cirrus deck as ascent associated with a weak shortwave trough emerges over the Plains. Expect these storms to continue to increase in coverage, and considering the 50F temperature/dewpoint spreads, expect outflow dominant storms and a congealing cold pool. There is some uncertainty how the storms will evolve, but given the environment with a hot and unstable airmass to the west and very high moisture content to the east with moderate shear and very steep lapse rates, expect an MCS to develop with the potential for intense wind gusts (perhaps has high as 100 mph). A severe thunderstorm watch will be needed for this threat in the next 1 to 2 hours and a PDS severe thunderstorm watch may be considered. ..Bentley/Smith.. 07/25/2026 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...FSD...ABR...LBF...UNR... LAT...LON 44170221 44900061 45029856 44819662 43819654 43379694 43039743 42990042 43050140 43580230 44170221 MOST PROBABLE PEAK WIND GUST...85-100 MPH MOST PROBABLE PEAK HAIL SIZE...UP TO 1.25 IN