Mesoscale Discussion 1856 NWS Storm Prediction Center Norman OK 0457 PM CDT Fri Aug 07 2026 Areas affected...Parts of central/eastern IA Concerning...Severe Thunderstorm Watch 541... Valid 072157Z - 080000Z The severe weather threat for Severe Thunderstorm Watch 541 continues. SUMMARY...A threat for hail, damaging gusts, and a tornado or two will continue into the early evening. DISCUSSION...An intense storm cluster with a history of producing brief tornadoes, large hail, and localized strong to severe gusts is moving southeastward across eastern IA late this afternoon. Surface observations and objective mesoanalyses suggest this cluster will begin to encounter weaker MLCAPE and greater MLCINH with time and eastward extent, though given its current organization, some severe threat may eventually spread east of WW 541. The strongest lapse rates and buoyancy extend southwest of the ongoing convection, with the 18Z OAX sounding depicting very steep midlevel lapse rates and seasonably cool temperatures aloft. This should allow for additional storm development along the trailing front into central IA. While deep-layer flow weakens slightly with southwest extent, effective shear of 30-40 kt in the presence of 3000-4000 J/kg of MLCAPE will favor isolated supercell development along the front, with an attendant threat of large to very large hail, damaging gusts, and possibly a tornado or two. ..Dean.. 08/07/2026 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...DVN...ARX...DMX... LAT...LON 42199429 42509251 42759148 42839123 42649083 42239042 41899048 41669097 41559201 41469295 41379377 41349434 41529456 42199429 MOST PROBABLE PEAK TORNADO INTENSITY...85-110 MPH MOST PROBABLE PEAK WIND GUST...55-70 MPH MOST PROBABLE PEAK HAIL SIZE...1.50-2.50 IN
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