Mesoscale Discussion 1482 NWS Storm Prediction Center Norman OK 0833 PM CDT Fri Jul 03 2026 Areas affected...Far eastern Iowa into northern Illinois Concerning...Severe Thunderstorm Watch 451... Valid 040133Z - 040330Z The severe weather threat for Severe Thunderstorm Watch 451 continues. SUMMARY...Although MCS intensity has been lackluster thus far, sporadic severe winds remain possible across far eastern Iowa into northern Illinois. DISCUSSION...Over the past hour, a loosely organized MCS has emerged across far eastern IA into northwest IL. However, a prominent outflow boundary is evident from KDVN surging ahead of the primary convective cores. Despite favorable buoyancy downstream and only gradually increasing MLCIN with the onset of nocturnal cooling, regional 00 UTC RAOBs and recent VWP observations show 20 knot southwesterly deep-layer wind shear vectors, oriented mainly parallel to the axis of convection. Additionally, very weak low-level winds are noted, which is also promoting outflow-dominant storms. Despite these trends, occasional bursts of strong/severe winds have been evident in velocity data, primarily as new updrafts develop and collapse within and ahead of the line. This trend should continue through the next few hours as the band gradually shifts east/southeast. In the short-term (next 1-2 hours), somewhat higher confidence in severe winds will be focused on the northern fringe of the line where better orientation to the deep-layer shear vector has allowed for a more balanced updraft/downdraft convergence zone. This section of the line will likely continue to propagate east/northeast into northeast IL where temperatures have recovered into the low 80s ahead of the band. ..Moore.. 07/04/2026 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...LOT...ILX...DVN... LAT...LON 41329178 42058971 42368878 42378820 42298778 41958753 41688748 41378751 41158762 40988806 40888849 40899144 40929165 41009182 41159192 41329178 MOST PROBABLE PEAK TORNADO INTENSITY...UP TO 90 MPH MOST PROBABLE PEAK WIND GUST...55-70 MPH MOST PROBABLE PEAK HAIL SIZE...UP TO 1.25 IN
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