Marine Weather and Tide Forecast for Marine City, MI

AVIATION

Surface high pressure gradually vacates in favor of a southern stream upper low that will slowly dislodge into the Ohio Valley tonight into Tuesday. Today begins with mostly sunny skies and light northeast flow, but a gradual increase in high cloud is anticipated by early evening. Winds remain light and veer toward the southeast this morning through the end of the TAF period. Ceilings lower steadily tonight and Tuesday morning amidst shower activity, comfortably falling below 1000 feet and possibly to or below 500 ft for a brief period around 12z Tuesday morning. That said, dry low levels may inhibit the more pessimistic stratus build down scenarios or at least delay onset. Thus will carry the inherited IFR cigs for all TAF sites Tuesday morning.

For DTW/D21 Convection... No thunderstorms are expected through the forecast period.

THRESHOLD PROBABILITIES...

* High in ceilings aob 5000 feet Monday night.

* Low for cigs/vsby to fall below 200 ft and/or 1/2 SM Tuesday morning.

PREV DISCUSSION
Issued at 402 AM EDT Mon May 12 2025

DISCUSSION...

A dry airmass remains in place today with high degree of dry air noted at 850mb on the 00Z DTX RAOB, which brings clear skies to start the day. Quiet weather conditions will hold through the remainder of the day has upper ridging builds further east over the region and the main surface high slides off the Atlantic Coast. There will be a noticeable increase in lower level thermal and moisture profiles throughout today, which will help drive afternoon temperatures upward to around 80 degrees for inland areas while the east-southeasterly flow will keep lakeshore areas cooler.

Tonight will see increasing rain chances as a closed mid level low begins to drift northward from the gulf states. Vorticity advection around the northern end of the low with improving theta-e will help support this initial round of elevated scattered activity late this evening/tonight. Very limited instability should keep thunder at bay.
Heading into Tuesday and Wednesday, continued waves of vorticity advection with better moisture quality will support daily rainfall chances. Greatest coverage each day will more than likely focus around the diurnal maximum when instability is at its peak. There will be a chance for isolated to scattered thunderstorms each day, but the weak lapse rates and weak low-mid level flow that tops out around 20 knots will be limiting factors preventing a more intense convective response. Overall cloud cover and scattered rain will keep daytime high temperatures mostly in the 70s.

The mid-week trough will give way to a much more potent trough swinging across the Northern Plains and Midwest on Thursday. The increase in southwest flow will bring temperatures back into the low 80s while dewpoints climb into the 60s. Brief downstream ridging will also bring keep weather dry for the majority of the day Thursday. Focus will be on the upstream convective response with favorable dynamics during the afternoon into the evening. Expect rain and thunderstorms focused along a line or broken line to drive across Lake Michigan and western portions of the state before arriving to southeast Michigan after 8 pm. The overall environment would be supportive of organized convection upon arrival given the increased shear with the typical question of available instability given the late timing. Strong to possibly severe thunderstorms will be possible should enough instability hold into the night.

A series of front forecast to sweep through Michigan Friday and over the weekend. Broad brush of PoPs during this period marks the general uncertainty in exact timing of features that may result in showers and thunderstorms, which are focused mainly on Friday night and Saturday. Cooler air will eventually arrives across southeast Michigan bringing temperatures back to around the average (upper 60s and lower 70s) for the weekend.

MARINE...

Modest return flow/southeast winds today drawing moisture northward.
Periods of showers and isolated thunderstorms expected to develop this evening through Wednesday, as a large low pressure system lifts out of the southern Mississippi River Valley. With the mild nature of the airmass however, winds outside of any convection will remain light through the mid week period. A stronger storm system slowly tracking through the northern Plains to end the work week will likely trigger additional showers and thunderstorms, some of which could be strong.

DTX WATCHES/WARNINGS/ADVISORIES
MI...None.
Lake Huron...None.
Lake St Clair...None.
Michigan waters of Lake Erie...None.