Marine Weather and Tide Forecast for Manchester, MI

AVIATION

Sfc high pressure over Se Mi and dry ambient airmass has caused a general erosion of the stratus across much of Se Mi. Developing southwest flow in advance of an approaching cold front will focus the stratus deck across the mbS and FNT region this afternoon.
Forecast expansion of the low clouds late this afternoon evening will increase chances for low cloud re expansion across the remainder of the terminals later in the day. The cold front is forecast to track across Se Mi between 06Z and 12Z Saturday morning. Frontal convergence and enhancement off Lake Mi will support an area of light snow showers along/in advance of the front. The overall brief period of stronger forcing will keep snow accums less than an inch.

For DTW...The window of opportunity for snow showers will be between 06Z and 10Z. A forecast weakening of the forcing as the front moves across Se Mi suggests just a potential for a dusting of accumulation overnight

DTW THRESHOLD PROBABILITIES...

* Low in ceilings below 5000 feet this afternoon. Moderate tonight and low Sunday.

PREV DISCUSSION
Issued at 248 AM EST Fri Dec 12 2025

DISCUSSION...

A shortwave tracking through far southern Lake Michigan has helped sustain clouds over much of southern Lower Michigan, holding temps in the low to mid 20s at press time. Areas which cleared out, northern Thumb region, tanked into the single numbers. Inversion heights are forecasted to lower slightly, thus still opportunity for low clouds to scour out and temps to dip, but there is also some high clouds noted across the area.

Strong PV Anomaly over the Central Canada with additional upper level energy coming out of the Gulf of Alaska on track to move through the Central Great Lakes Saturday and Saturday night. Bitter cold arctic airmass will overspread Lower Michigan, with -30 to -32 C advertised at 700 mb, with Lake Michigan modified 850 mb temps of -20 C or slightly colder for second half of the weekend. Meanwhile, aggressive height falls tracking through the northern Great Lakes this evening, tapering off toward the southern Michigan border. None- the-less, with west-southwest flow coming off Lake Michigan and the low level convergence/fgen of the arctic front moving through, a period of scattered-numerous snow showers looks likely as 1.75-2.0 g/kg of 850 mb specific humidity tracks through Saturday evening- night. With short lived forcing at any given location (<3 hrs), would expect accumulations of a dusting to less than an inch.
Excellent drying and subsidence to follow frontal passage, with mean 850-700 mb dew pts depressions of 25 C taking hold over the bulk of southeast Michigan. This will be key, as very strong Jet streak (90- 100 knots at 500 mb) and another impressive 500 mb height fall center tracks through the northern Ohio Valley during Saturday/Saturday evening. Locations along and especially south of I- 94 could get clipped with the northern fringe of the snow shield, but the forcing/airmass is colder than the DGZ, and snowflakes should be fine, and thus would only expected another dusting to perhaps an inch right along the border.

As usual with the very dry arctic airmass, tough to gauge how much lake clouds/light snow showers/flurries make it eastward Saturday night, as surface dew pts of -15 to -20 F spread into Wisconsin.
Even if skies do in fact clear out, looks like surface winds will not be able to fully decouple, with light surface winds preventing temps from cratering much below zero. Euro ensembles indicating 40- 50 percent chance of 2M temps dropping at or below zero over central sections of the CWA at 12z Sunday. None-the-less, that will place wind chills in the 10 to 15 below zero range. Will have to keep a close eye on the eastern Thumb shoreline on Sunday as winds do look to veer around to the north-northwest as the mid level cold pool/wave exits the Central Great Lakes.

Shortwave coming over the top of the upper level ridge over the Rockies swings through Lake Huron on Monday. Pretty good isentropic ascent progged with just enough moisture to support light snow showers, epsecially as one heads north. Right now, 00z Canadian looks to be one of the more aggressive solutions, with 5 hundreths to a tenth of an inch of qpf. NBM pops have at least increased to more solid chance pops.

Warm air breaking off from the upper level ridge off the West Coast next week as the upper level flow transitions to the zonal over the northern Conus by mid week. NBM temps indicating low to mid 40s by Thursday with a good chance of rain as next deepening low pressure system enters the picture.

MARINE...

Elongated area of high pressure remains centered over the region today before sliding southward into the Ohio Valley this evening into tonight. This will provide a brief period of lower winds and wave heights today which ramp back up tonight in advance of the next low pressure system. This low will track across Ontario Friday night while pulling an arctic front across the region. This very cold airmass will again bring increased westerly winds across the area with wide spread gusts to 30 knots across much of Lake Huron and sporadic gusts to gales possible during the weekend as 850 mb temps plummet to -20 C. At a minimum, another round of Small Craft Advisories will need to be issued at some point for tonight through much of the weekend as the arctic air holds over the region. This cold airmass and elevated winds will also lead to potential snow squalls and freezing spray as well.

DTX WATCHES/WARNINGS/ADVISORIES
MI...None.
Lake Huron...Small Craft Advisory from 10 PM this evening to 4 AM EST Monday for LHZ421-441.

Small Craft Advisory from 10 PM this evening to 4 PM EST Saturday for LHZ422.

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