A 4Warn Weather Alert remains in effect for Southeast Michigan due to a combination of dangerous heat today followed by the potential for severe thunderstorms later tonight. A Heat Advisory continues for communities south of M-59 through this evening. Temperatures will climb into the upper 80s and lower 90s, while high humidity levels will push heat index values close to 100 degrees during the afternoon. Anyone spending extended time outdoors should stay hydrated, take frequent breaks, and limit strenuous activity during the hottest part of the day.
While much of the daytime period will remain dry, we are keeping a close eye on a warm front draped across the region. As the saying goes, “Never trust a warm front.” A few isolated showers or thunderstorms could develop this afternoon (noon to 6pm) along the boundary, but the more significant concern arrives later tonight. The Storm Prediction Center continues to place Southeast Michigan under a Slight to Enhanced Risk for severe weather between approximately 8 p.m. and 3 a.m. A line of thunderstorms is expected to develop ahead of an approaching cold front and track eastward across the state overnight. All severe weather hazards will be possible with these storms. The primary threats include damaging wind gusts up to 75 mph) and embedded tornadoes within the line of thunderstorms. Large hail and localized flooding are also concerns, especially where the strongest storms develop.
There is still some uncertainty regarding the overall severity of the event. One possibility is that the line of storms weakens before reaching Southeast Michigan, which is best case scenario. Another scenario would have the most intense thunderstorms track farther south, limiting the severe threat locally. Even so, Metro Detroiters should remain weather aware and have multiple ways to receive warnings overnight when storms are expected to move through, especially around and after midnight.
The good news is that relief arrives quickly behind the cold front. Cooler and much less humid air will filter into the region on Friday and remain in place through the weekend. High temperatures will return to more comfortable levels with pleasant conditions expected for outdoor activities. Looking ahead, temperatures are forecast to settle back into the 70s for much of next week, providing a welcome break from the early-season heat but some early week rain showers can’t be ruled out.