textproduct: Detroit/Pontiac

KEY MESSAGES

- Scattered light rain showers decrease in coverage through the evening.

- A Freeze Warning is in effect for all of Southeast Michigan tonight.

- Only stray shower chance Saturday though most stay dry. Dry conditions hold through early Sunday before rain and thunderstorm chances rise early next week.

DTW THRESHOLD PROBABILITIES

* Medium for cigs aob 5000 feet tonight. Low Saturday.

PREV DISCUSSION

Issued at 256 PM EDT Fri May 1 2026

DISCUSSION...

Pattern remains unchanged today with southern lower MI holding under broad upper troughing with weak CAA supporting a widely scattered coverage of light showers/sprinkles. Lingering showers wind down around sunset as diurnal instability wanes however exactly how much of the accompanying cloud cover clears tonight carries a high degree of uncertainty with a healthy spread amongst the high res solution space. There is fairly good agreement that areas west of I-75/US-23 stand the best chance at true clearing and subsequent sub-freezing temps. For areas east, there is some potential for enough meaningful cloud to remain to keep temps near or slightly above 32. With that said, will err on the cooler side in coordination with neighbor WFOs and upgrade the Freeze Watch to a Freeze Warning.

Largely a persistence forecast Saturday as thermal troughing holds over the state for one last day capping highs around 50F. Passage of a trailing vort max offers a slight chance for a few isolated/widely scattered afternoon showers however forecast soundings advertise a shallower saturation layer relative to previous days keeping any coverage minimal.

Trough influence breaks down Saturday night as zonal or quasi-zonal mid-level flow develops allowing elevated theta-e advection to be drawn into lower MI Sunday. Light scattered shower chances increase latter half of the day Sunday as a weak embedded shortwave crosses into the Great Lakes. Main warm advection arrives early Monday as deep layer southwesterly flow is established in response to an Alaskan wave digging into the northern Plains. 850mb temps rise from 4-5C Mon AM to 8-9C by Mon PM supporting highs returning to the 60s to around 70. Associated surface cold front looks to arrive over the central Great Lakes Monday evening-night bringing the area's next shot at wider spread showers and thunderstorms. While a general active, cooler pattern is favored for much of the week, how progressive this surface front and parent upper trough are is still unclear this far out.

MARINE...

A large and slow moving upper level low will stall over the Great Lakes through upcoming weekend. Meanwhile we'll have a broad area of high pressure at the surface. This combination will lead to a fairly quiet stretch of marine weather with mainly clouds and light winds (gusts under 15 knots) through Saturday with an opportunity for a light shower mainly in the afternoon hours. Wind direction holds from the north to northwest through Saturday before wind direction backs to the southwest Sunday and holds through early next week as a warm front passes through the Great Lakes. Gusts on Sunday could reach 25 knots on Sunday behind the front in some of the nearshore zones. There will be additional chances for rain showers and a low chance for an embedded thunderstorm early next week.

DTX WATCHES/WARNINGS/ADVISORIES

MI...Freeze Warning from midnight tonight to 9 AM EDT Saturday for MIZ047>049-053>055-060>063-068>070-075-076-082-083.

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