textproduct: Detroit/Pontiac

KEY MESSAGES

- Dry weather returns Monday through Tuesday with cool nights (50s) and warm days (80s).

- The next chance of showers and possible thunderstorms arrives late Wednesday, with better coverage expected on Thursday.

- Mainly dry weather is expected for Friday and Saturday.

DTW THRESHOLD PROBABILITIES

* Medium for ceiling intermittently at or below 5000 ft through midnight.

PREV DISCUSSION

Issued at 245 PM EDT Sun Aug 2 2026

DISCUSSION...

All hydro related headlines have been dropped as main low and deformation has exited east. A few locations along the western Lake Erie Shoreline saw rainfall in excess of 2 inches, fortunately thunderstorms remained offshore. The upper level wave and mid level cold pool (-12 to -13 C at 500 MB) tracking through northern Lake Huron is also triggering limited shower activity which will have to be accounted for. An isolated thunderstorm remains possible as well with the decent surface based capes noted in SPC mesoscale analysis (especially western Lower Michigan). Activity should quickly dissipate toward sunset.

A pleasantly warm and dry start to the workweek is expected as an upper-level ridge builds east, with the axis arriving Tuesday morning over the central Great Lakes.

A notable shortwave/upper-level wave currently tracking through Washington will move through northern Ontario and into James Bay. Thus, limited height falls are expected over southern Lower Michigan for the midweek period. A surface cold front will be positioned near/just northwest of the CWA a and will service as a focus for convection. The timing of this frontal passage and the activation/response of showers and possible thunderstorms vary amongst medium-range models. Thursday appears to be the favored day for best coverage of activity. Euro ensemble suggests 24-hour probability of a tenth of an inch or more of QPF is 60+ percent, centered in the 06Z Thursday to 06Z Friday timeframe.

A broad/loosely defined upper-level trough axis will be in place on Friday, persisting into Saturday. However, troughing looks to be weak, with pseudo-zonal upper-level flow established over the northern CONUS over the weekend. With strong high pressure in place over the central Appalachians extending into southeast Michigan, we expect mainly dry conditions on Friday and Saturday.

MARINE...

Modest northeast flow persists across the central Great Lakes through the evening and early overnight hours until a low pressure system exits the Ohio Valley into Appalachia. The strongest flow will channel across Saginaw Bay with elevated winds and waves reaching Small Craft Advisory criteria first, then conditions expand to the rest of the Lake Huron nearshores. The chance for additional showers and thunderstorms wanes this evening as the main axis of showers clears east. High pressure influence then builds into the region overnight and into Monday offering drier weather and weaker winds. Light flow flips southerly on Tuesday as the center of high pressure slides across Lake Erie. A slow moving frontal boundary will drift in from the west mid-week leading to future opportunities for showers and thunderstorms. No significant pressure gradient constriction is forecast, therefore headline-free conditions should persist through the end of the week.

DTX WATCHES/WARNINGS/ADVISORIES

MI...Beach Hazards Statement until 10 PM EDT this evening for MIZ049.

Lake Huron...Small Craft Advisory until 4 AM EDT Monday for LHZ441>443.

Small Craft Advisory until 10 PM EDT this evening for LHZ421-422.

Lake St Clair...Small Craft Advisory until 4 AM EDT Monday for LCZ460.

Michigan waters of Lake Erie...Small Craft Advisory until 4 AM EDT Monday for LEZ444.