Area Forecast Discussion

KEY MESSAGES

- Cooler but still above normal temperatures today and Saturday.

- Low chance for a few light showers late Saturday towards central MI.

- Warm conditions with humidity will be possible early to middle next week.

AVIATION

Shallow post-frontal moisture advection within prevailing northwest flow will maintain some filaments of lower stratus this morning. Observational and satellite trends suggest limited enough coverage to maintain simply a scattered mention thru the duration of the morning period. Otherwise, increasingly dry and stable conditions will offer mostly clear skies during the daylight period. High cloud thickens and gradually lowers tonight as high pressure shifts through the region. Existing north to northwest wind turning light and variable overnight.

D21/DTW Convection...Thunderstorms are not forecast through the TAF period.

DTW THRESHOLD PROBABILITIES

* low for cigs at or below 5000 ft Friday morning.

PREV DISCUSSION

Issued at 339 AM EDT Fri Oct 30 2026

DISCUSSION...

Upper Midwestern surface high pressure fully expands over lower MI today promoting mostly sunny-partly cloudy skies and a light northwest breeze. Thermal troughing following yesterday's cold front only glances the area, focused towards Lake Huron, supporting a 'cool' day though still a few degrees above late October normals with highs ranging mid-50s (Thumb) to low 60s towards Ohio. Generally favorable radiative cooling setup tonight as the center of high pressure drifts overhead turning winds calm, though cirrus tied to a developing warm front over the Midwest will attempt to lift in from SW MI. This likely results in a decent SW-NE gradient in overnight lows with the northeastern half, where cloud cover will be lesser, seeing lows well into the lower 30s whereas the southwestern half see lows in the upper 30s to lower 40s.

Influence of said high holds for the bulk of the day Saturday maintaining dry conditions save for perhaps the Ohio border area. Aforementioned warm front lifts into the upper Mississippi/western Great Lakes latter half of Saturday before washing out Saturday night. Accompanying moisture transport is directed west of Lake Michigan as only the periphery of elevated theta-e reaches SE MI. Given the resident dry airmass still in place from the prior high, rain activity will struggle the further east it advances across the state. As a result, areas closer to central/south-central MI stand the best shot at seeing isolated to scattered light showers (only a few hundreths of QPF at best) Sat-Sat night.

Early week remains unclear wrt to rain chances as diffuse vorticity (tied to the old front) works into Ohio Valley/southern Great Lakes. Secondary push of theta-e, now in the lower levels as well, offers a low chance for scattered light showers early Monday however weak synoptic forcing acts as a limiting factor with some model solutions remaining dry. Mid-late week period characterized by large Pacific Northwest upper trough slowly translating across the central CONUS. Slow moving attendant cold front eventually offers the areas next chances for wider spread rainfall as well as at least a brief return towards late fall temperatures.

MARINE...

Northwest flow holds for most of the day in the wake of a cold front. The cold air advection taking place behind the cold front will elevated mixing depths, allowing stronger air aloft to mix down which will sustain gusts ranging around 20 to 25 knots across Lake Huron through the morning. Localized gust potential up to 40 knots will be possible across north and north-central Lake Huron where the favorable fetch aligns. High pressure to then build in tonight and into the weekend which will then bring a period of light winds. A low pressure system will track across the Plains early next week, increasing chances for more active conditions across the Great Lakes by the midweek period.

DTX WATCHES / WARNINGS / ADVISORIES

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