Day 1 Convective Outlook
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Issued: · Valid: –
Summary
Scattered damaging winds are possible this afternoon through this evening across parts of southern Wisconsin, northern Illinois, southern Michigan, northwest Ohio, and northern Indiana. Damaging winds and hail may also occur across portions of the Dakotas tonight.
Product Text
000 ACUS01 KWNS 091558 SWODY1 SPC AC 091556 Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1056 AM CDT Sun Aug 09 2026 Valid 091630Z - 101200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON OVER PARTS OF THE MIDWEST...AND TONIGHT OVER PARTS OF THE DAKOTAS.... ...SUMMARY... Scattered damaging winds are possible today into this evening from southern Wisconsin eastward across parts of northern Illinois, southern Lower Michigan, northwest Ohio, and northern Indiana. Damaging wind and hail may also occur across portions of the Dakotas tonight. ...Midwest... A persistent cluster of thunderstorms over southern WI appears likely to continue southeastward through much of the day into parts of IL/MI/IN and eventually OH. This activity will track near a NW-SE oriented baroclinic zone, with dewpoints in the lower 70s to the south. Eventually, low-level lapse rates will become sufficiently steep to support damaging wind gusts along the leading edge of the storms. Later tonight, strengthening southwesterly low-level winds will enhance warm advection and lift over parts of IL/IN, potentially leading to another round of strong/severe storms capable of damaging winds and hail after 06z. ...Dakotas... 12z model guidance continues to decrease the confidence in overnight severe storms, with some CAM solutions showing no thunderstorms. Therefore have made the SLGT area smaller and focused where there is highest confidence in isolated storms. Forecast soundings continue to indicate steep mid-level lapse rates and strong deep shear, providing a conditional risk of supercells if convection can be sustained. ...AZ... Thunderstorms are once again predicted to form along the Rim and track westward toward the PHX metro area this evening. The strength of the steering flow, instability, and mid-level moisture all appear favorable for a severe risk. However, mesoscale details of the evolution of the storms over high terrain will dictate the eventual risk. ..Hart/Weinman.. 08/09/2026 $$