textproduct: Detroit/Pontiac

KEY MESSAGES

- A narrow corridor of lake effect rain showers (briefly mixed with melting snow) persists into tonight, mainly along the southern Lake Huron shoreline.

- Mostly cloudy skies expected through the weekend.

- Dry weather expected area-wide Monday through Thursday with a steady warming trend.

DISCUSSION

Broad mid-upper trough centered over the eastern Great Lakes remains the primary driver of local sensible weather through tonight. Ample lake moisture flux within northwesterly flow maintains robust coverage of low cloud this evening through tonight. While embedded ripples of vorticity rounding the trough could squeeze low level moisture fields just enough for a couple light showers/drizzle this evening, vast majority stay dry for the rest of the day. These localized vort maxes are expected to reinvigorate ongoing lake effect showers along the southern basin of Lake Huron late evening- tonight however. While initially (through this evening) the eastern Thumb would reside along their westernmost fringe, there is a window overnight into early Sunday morning where lower level winds develop a more northerly component, tied to reorganization of the upper trough over the St Lawrence Seaway, allowing activity to push deeper into the Thumb. Precip remains all rain for the lakeshore areas given the relatively mild Lake Huron. In the event showers shift further inland tonight, even these areas are favored to stay mostly or all rain as column saturation is confined sub 6kft well below the DGZ hampering ice nuclei formation.

Sunday is the transition day between departing eastern CONUS troughing and approaching central CONUS ridging. Lingering lake effect showers along southern Lake Huron gradually wind down over the course of the day as increasing subsidence and weak warm advection from Midwestern surface high pressure work into SE MI. Weakening winds slow the pace lingering low level moisture is scoured out though, resulting in persistent cloudier skies and highs still capped in the 40s.

First half of the new work week is governed by ridging which is firmly in place across the Great Lakes by this point. Steady moderation in temperatures each day can be expected as above normal highs in the 50s return. Influence of high pressure also leads to mostly sunny skies and modest southwesterly winds setting up a pleasant stretch of weather. Next chances for rain don't arrive until late week as a Desert Southwest shortwave eventually reaches the northern Great Lakes. That said, how much if any rain SE MI could see is tied to how far north the wave tracks.

MARINE

Cool northwesterly flow will persist tonight which maintains the breezy conditions across Lake Huron. Gusts ranging between 20 to 30 knots will be likely through Midnight. Lingering rain showers will also be possible across the southern Lake Huron basin. High pressure will then begin spreading across the Great Lakes tomorrow morning, which will result in rapidly decreasing wind speeds in the morning hours. By the late afternoon and evening hours, light winds will have settled in as high pressure situates over the Great Lakes. Southwest flow will become established by Monday once this high pressure progresses east. This will bring some localized stronger winds through the Saginaw Bay into central Lake Huron, but overall dry weather and lighter wind speeds are expected into the midweek period.

PREV DISCUSSION

Issued at 1220 PM EST Sat Nov 14 2026

AVIATION...

Surface high pressure spans a broad area from northern Ontario to the Gulf coast, along the MS river valley, but is slow to move eastward this afternoon and tonight. This maintains NW flow that is cold enough to support widespread activation of Great Lakes clouds across Lower Mi through at least Sunday morning. Satellite and surface observations leading into this afternoon report MVFR below 2000 ft across the region that grinds up above 2000 ft with a few breaks at times during peak daytime heating. Model soundings indicate an adequate subsidence inversion developing just in time to trap broken MVFR tonight and Sunday morning. Another round of diurnal enhancement fights against inbound high pressure for slow improvement Sunday afternoon.

For DTW... Ceiling remains below 5000 ft during any breaks of MVFR this afternoon. NW wind off the slightly higher terrain is also capable of producing MVFR ceiling variability tonight through Sunday.

DTW THRESHOLD PROBABILITIES...

* High for ceiling at or below 5,000 feet this afternoon and tonight.

DTX WATCHES/WARNINGS/ADVISORIES

MI...None. Lake Huron...Small Craft Advisory until 10 AM EST Sunday for LHZ421-441>443.

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