Marine Weather and Tide Forecast for Village of Grosse Pointe Shores, MI

AVIATION

Dense near surface smoke infiltrated the TAF sites this evening immediately following the passage of the surface front. Visibilities within the smoke have ranged from a half mile to two miles. Given the strong boundary layer stability during the night, the TAFs will maintain IFR prevailing conditions. Diurnal heating on Thursday will offer the potential for more mixing and will thus warrant prevailing MVFR during the daytime.

D21/DTW Convection...The risk of convection has ended as more stable air slowly expands across the area.

DTW THRESHOLD PROBABILITIES

* Medium for ceiling/vertical visibility at or below 5000 feet tonight and Thursday.

PREV DISCUSSION
Issued at 348 PM EDT Wed Jul 15 2026

DISCUSSION...

The southward advancing smoke plume remains the weather highlight in this update. Afternoon satellite and surface observations indicate the leading edge of denser smoke near the I-69 corridor at forecast issuance, tracking closely with the southward progress of the surface cold front. Model timing adjusts the leading edge timing down to the Ohio border closer to midnight. The Air Quality Alert is in effect now through tonight.

The timing of the front and advancing smoke has allowed most locations outside of the northern Thumb to warm up into the lower and mid 90s, with lower to mid 70s Td carrying heat index into the advisory range above 100. The Heat Advisory has been cancelled for the Thumb but remains in effect until 8 PM for the rest of SE Mi.
The heat and humidity have also built up an impressive amount of potential instability as hourly mesoanalysis shows MLCAPE climbing into the 2000-2500 J/kg range. This has so far been held in check by a fragile capping inversion in the 850-700 mb layer. HRRR and REFS mean QPF suggest holding on to an isolated mention through the evening with a few individual members showing initiation post 00Z.

Dry weather later tonight and in the morning allows wildfire smoke to burrow into the region. Impressive persistence of the plume through Thursday is shown in today's HRRR model runs of near surface smoke density over the Great Lakes. Values observed today across the northern Great Lakes are projected to hold over all of Lower Mi Thursday and Thursday evening prompting extension of the Air Quality Alert. The smoke is shown to be strongly confined within the stable boundary layer within the area of surface high pressure covering the region. There is some potential for deeper boundary layer mixing in forecast soundings Thursday afternoon which aids in slowly decreasing concentrations late in the day and Thursday evening.
Conditions are dry otherwise as the band of mid/upper level clouds currently over the northern Great Lakes settles southward with less coverage. Cooler temperatures are the result when combined with the smoke layer and northerly wind limiting factors that hold high temperatures in the mid to upper 80s, toward the lower end of guidance ranges. Less humid air is also inbound post front carrying surface Td down to around 60 by Thursday morning where it holds through the day.

High pressure holds dry weather over the central Great Lakes for the bulk of Thursday night while the next low pressure system organizes in the northern Plains. This system initiates an active period of showers and thunderstorms beginning with accelerated moisture transport ahead of an inbound warm front Friday. Weekend time range models then show the low moving across the northern Great Lakes followed by the trailing cold front that is shown to be on the active side while moving through Lower Mi.

MARINE...

A weak backdoor cold front continues south across the central Great Lakes today and is approaching Lake St. Clair. This allows winds to eventually veer toward the north-northwest behind the front. Wind speeds still only top out around 20 knots through this evening, more so over the northern half of Lake Huron where the post-frontal gradient is a bit stronger. Dense smoke due to Canadian wildfires is spreading southward in the wake of the boundary, and is expected to continue into the overnight hours. Therefore, expanded the Dense Smoke Advisory to the rest of Lake Huron and also Lake St. Clair.
May need another extension for Lake Erie depending on where the front ends up later this evening.

A couple pop-up storms are still possible along the frontal boundary and/or lake breeze development late this afternoon and early evening. The probability of severe weather with any isolated storms is low. North-northwest winds at or below 20 knots expected again Thursday afternoon with the higher values over the northern half of the Huron basin. Forecast confidence breaks down over the weekend due to conflicting model guidance regarding the location and magnitude of a weak surface low passing through Lower Michigan, which will impact wind trends and thunderstorm potential. Prevailing winds should generally remain below headline criteria through the forecast period, with one exception being marginal Small Craft Advisory gusts over Saginaw Bay and/or The Thumb nearshores Saturday afternoon.

DTX WATCHES/WARNINGS/ADVISORIES
MI...None.
Lake Huron...Dense Smoke Advisory until 10 AM EDT Thursday for LHZ361>363-421- 422-441>443-462>464.

Lake St Clair...Dense Smoke Advisory until 10 AM EDT Thursday for LCZ460.

Michigan waters of Lake Erie...Dense Smoke Advisory until 10 AM EDT Thursday for LEZ444.