There is a significant chance of severe weather this afternoon into tonight across southeast Michigan. A first wave of storms will occur as a warm front lifts through the region, and a second wave as a corresponding cold front moves through later tonight.
This afternoon and evening, expect strong and potentially severe thunderstorms with heavy rain, damaging wind gusts (up to 60mph), and localized hail up to 1″ in diameter.
Tonight (after 8pm until early morning), expect yet stronger storms with more intense wind gusts (up to 70mph), heavy rain, and localized golf-ball-sized hail. This second wave of storms comes with a tornado risk as well; there is a relatively significant chance for tornados to form in SE Michigan. The risk is greatest north of M-59; NWS reports the risk north of M59 is from 9pm-2am and south of M59 (so, for Ann Arbor) is from 11pm-4am.
Skywarn spotter activation is likely with these storms.
As always, it is not possible to predict ahead of time exactly when a storm will strike Ann Arbor specifically; these predictions are for the larger SE Michigan region at this time.