textproduct: Detroit/Pontiac

KEY MESSAGES

- Cooler today with pockets of light rain and drizzle, especially across the Thumb. A northwest breeze keeps wind chill around 40 degrees.

- Dry weather helps temperatures rise a few degrees above normal again during the weekend and early next week.

DTW THRESHOLD PROBABILITIES

* High for ceiling 5000 ft or less today and tonight.

PREV DISCUSSION

Issued at 415 AM EST Fri Nov 6 2026

DISCUSSION...

A deep upper low is advancing across Lower MI this morning with an impressive presentation to the closed circulation noted in satellite WV imagery. Fgen associated with the aggressive height falls and PVA exits to the east over the next hour with a surge of dry air aloft quickly working in from the northwest. This brings an end to the light to moderate rainfall, with a lull in precip until mid morning when deeper moisture sweeps back across the area. Cool northwest wind with pockets of lake enhanced light rain and/or drizzle bring a raw, grungy day with temperatures to struggling to reach 50 degrees this afternoon.

As the deep cyclonic circulation passes overhead, a surface mesolow is forecast to drop across Lake Huron this afternoon and evening. This brings a strongly forced mesoscale band of rain within the trowal/deformation axis into the vicinity of the eastern Thumb. Given the scale of forcing, placement of the heaviest rain carries uncertainty but confidence has increased for rainfall totals in excess of 0.50" from Port Austin to Port Hope and Harbor Beach. A small handful of hi-res solutions and individual members of ENS and GEPS ensembles indicate potential for localized areas to receive over 1 inch in the event the mesolow is slower to pass into the Ontario peninsula tonight. Surface temps in the 40s and wet bulb zero heights as low as 2000 ft offer high confidence in rain as the ptype.

Light rain may linger into Saturday morning along the Thumb shoreline, otherwise negative vorticity advection ensues in the wake of the departing upper low to cease precip chances. Moist cyclonic flow below 800mb keeps a good amount of clouds around Saturday and thermal troughing helps hold high temps in the lower 50s. Shortwave ridging crests over the area Saturday night before the next trough arrives from the northwest on Sunday. This wave is also deep but more progressive, targeting Lake Huron with its main height fall corridor. Light rain may brush the Thumb, but the main impact locally will be a breezy westerly wind as the system passes to the north. Milder conditions develop Sunday into Tuesday as positive upper height anomalies prevail over the upper Midwest and Great Lakes. This period is generally devoid of organized forcing, favoring dry conditions.

MARINE...

Trough of low pressure remains stretched from Quebec southwestward through the central Great Lakes early this morning. An upper low drifting south overnight is causing the surface trough to close into a low over central Lake Huron this morning before the whole system drifts off to the south for the weekend. A trailing trough axis will get pulled through the area later today as well. Winds will be variable from lake to lake today with the circulation right over Huron. Lakes Erie and St Clair will remain in the northwesterly flow through the day with the track of the low, while northern Huron get into gusty northeasterly winds north of the low. The cold air advection is helping to increase mixing depths over the water and will help keep the winds speeds and waves elevated through this time across Lake Huron. This will all lead to an extended period of Small Craft Advisories across much of the waters now through Saturday morning. Will need to watch western Lake Erie tonight into Saturday morning for brief period of winds gusts to around 25 knots.

DTX WATCHES/WARNINGS/ADVISORIES

MI...None. Lake Huron...Small Craft Advisory until 4 PM EST Saturday for LHZ421-441.

Small Craft Advisory until 10 AM EST Saturday for LHZ422.

Small Craft Advisory until 4 PM EST Saturday for LHZ442-443.

Lake St Clair...Small Craft Advisory from 10 PM this evening to 10 AM EST Saturday for LCZ460.

Michigan waters of Lake Erie...None.