textproduct: Detroit/Pontiac

KEY MESSAGES

- There remains a chance of showers and thunderstorms through tonight. While widespread severe weather is not expected, an isolated stronger storm is possible.

- More seasonable temperatures and lower humidity are slated to return this weekend.

DTW THRESHOLD PROBABILITIES

* High for ceiling 5000 ft or less tonight and Saturday morning. Low Saturday afternoon.

PREV DISCUSSION

Issued at 224 PM EDT Fri Sep 4 2026

DISCUSSION...

Ongoing elevated convective activity fixated along a lingering baroclinic zone and within the background of continued sufficient mid level instability will settle to the south over the next couple hours. Lack of meaningful daytime heating within the immediate wake of the earlier activity offering a more notable reduction in available instability moving forward. This occurs within an environment seemingly lacking in greater tangible forced ascent as more pronounced shortwave energy embedded within the mean mid level northwest flow traverses south and west the area. Little evidence within short range model guidance to suggest additional larger scale redevelopment will occur at least through the back half of the peak heating cycle. A more localized response remains plausible, particularly near the Ohio border, given closer proximity to the deeper instability reservoir. It would be within this environment that s secondary, isolated opportunity remains for more organized cells to emerge locally or track in from southern WI late this evening into early tonight /22z-04z/ across that corridor. Forecast maintains a lower end chance mention most locations through the night, accounting for the presence of some elevated instability /highest with westward extent/ and sufficiently moist boundary layer conditions to support an early morning flare-up of showers.

The surface frontal zone sags south of the Michigan/Ohio border through Saturday morning. Isentropic upglide and lingering low-level convergence along the stalling frontal boundary will keep a low-end chance for scattered showers or an isolated rumble of thunder focused primarily across the southern tier of counties (M-59 southward to the Ohio border) early Saturday. Otherwise, significantly less supportive airmass as available instability lacks as surface dew points scour out into the upper 50s to lower 60s. Expect decreasing cloud cover from north to south through the afternoon as surface high pressure expands over the upper Great Lakes. Onshore lake-breeze components off Lake Huron will keep eastern and coastal areas cooler. High temperatures more comfortably top out in the mid-to-upper 70s Saturday. High confidence then exists in dry and benign conditions holding through the remainder of the weekend as expansive high pressure centers directly over Lower Michigan. The deep layer stability held with this environment ensures limited cloud production, while temperatures hover near- normal for early September.

Low to mid level ridging will continue to mark conditions during the early week period. Associated deep layer stability with a very dry profile ensures benign weather, with the incremental increase in the mid level height field netting a very modest warming trend but with temps still seasonable. Low-level return flow around the backside of the departing surface high pushes 850 mb temperatures back into the +16 to +18C range by Wednesday afternoon. An associated increase in low level moisture quality likely to commence at the same time ahead of an inbound cold front tied to a northern stream shortwave moving across Ontario. This will bring the next chance for meaningful rainfall, followed by a more notable cooling trend directed for the end of next week.

MARINE...

Greatest thunderstorm potential will generally remain south of the waterways through tonight, although an isolated storm cannot be ruled out. Otherwise, high pressure anchored over Ontario will increase influence heading into the weekend. This will bring drier and more stable conditions. Prevailing wind from the northeast may bring a modest increase in wave action along portions of the lake Huron nearshore waters, but are expected to remain below advisory levels at this time.

DTX WATCHES/WARNINGS/ADVISORIES

MI...None. Lake Huron...None. Lake St Clair...None. Michigan waters of Lake Erie...None.