Marine Weather and Tide Forecast for Auburn, MI

AVIATION

A low pressure system exits central Ontario into western Quebec tonight which ushers in a cooler airmass for the terminals into Tuesday. The coldest air will generally remain over northern Michigan, but sufficient cooling has supported the development of a stratocumulus deck this evening. Expectation is that cloud bases still hold in the low-end VFR range a bit longer before scattering out early Tuesday morning. The surface pressure gradient further relaxes with time tonight as the rate of improvement is dictated by the departure speed of the surface low. Surface high pressure builds into the Ohio Valley from the Mississippi Valley on Tuesday promoting a drier column locally with weaker west-southwest winds.
Mid-level moisture and resulting clouds spill downstream into Lower Michigan from The Plains Tuesday evening as surface flow backs southerly, due to the eastward translation of Ohio Valley ridging.

DTW THRESHOLD PROBABILITIES

* High for ceiling at or below 5000 feet until approximately 08Z tonight, then low for the rest of the morning hours.

PREV DISCUSSION
Issued at 315 PM EDT Mon Apr 21 2025

DISCUSSION...

Mature low pressure (~1000 mb) system exiting northeast of the northern Great Lakes this evening. Southwest wind gusts behind the fropa did peak out in the 40-50 mph range across southeast Michigan, especially and including south of M-59, as max temperatures reached into upper 60s to mid 70s. Still 45-50 knots of flow at the 850 mb level across the northern half of the CWA, and will thus maintain the wind advisory for now, although gusts to 45 mph will likely be sporadic. The northern tip of the Thumb region finally looks to get into the action and see the more frequent/peak winds as winds veer around to the west. Winds to diminish this evening and tonight, but winds still holding around 10 mph toward sunrise Tuesday. Thus, even with clouds slowly dissipating, should not have to worry about frost as temps dip into the upper 30s to around 40 degrees.

More disorganized, but abundant upper level PV/energy back across the northern Rockies, which will spin up a weak low/reflection in the Upper Mississippi River Valley/Midwest come Tuesday. Surface frontal boundary/increasing moisture looks to reach the southern Michigan border toward 00z Wednesday, and there may be enough mid level instability to allow for showers and even an isolated thunderstorm survive the trip into southeast Michigan by Tuesday evening. Mid level lapse rates are steep, greater than 7 C/km.
However, the low instability (Mucapes ~1000 J/kg) reservoir should mostly hold over the Western Great Lakes through Tuesday night. Still, 12z HRRR suggests west to east training of convective activity is possible with the modest westerly low level jet.

Modest sfc-850 mb based instability/cape developing during Wednesday south of I-69 may touch off scattered showers/isolated thunderstorms with weak low level convergence, leftover frontal boundary. However, modest height rises (500 mb heights of 573+ DAM) and some semblance of 500 mb ridge axis building over the Central Great Lakes, promoting general subsidence, leads to low confidence. NBM pops look ok with mostly slight chance (15-25).

Further height rises for Thursday, but potential shortwave coming out of the Midwest to end the work week, merging with a northern stream trough tracking out of south Central Canada. Cyclogensis taking place over the Western Ohio Valley by Friday should support widespread rain overspreading southeast Michigan, with the low on pace to exit east on Saturday. Any residual light rain ending early in the morning, with dry conditions then in place for the rest of the weekend, per 12z Euro.

MARINE...

Shallow mixing depths in the wake of a cold front will continue to interact with a shallow yet strong wind field aloft, bringing gusts to gales for the majority of the nearshore zones outside of western Lake Erie. Some sporadic gusts to gales remain possible for western Lake Erie, but latest observations preclude the issuance of any short-fused warning product, with expectation that gales for all nearshore zones diminish by late this evening. For Lake Huron, passage of a low pressure system will veer wind direction from the west with cooler air filtering in aloft, which will then pivot the gale threat to the northern third of Lake Huron overnight. A ridge of high pressure will build in through Tuesday afternoon, diminishing wind speeds through the day tomorrow. Light winds then continue through the midweek period as the pressure gradient remains weak.

DTX WATCHES/WARNINGS/ADVISORIES
MI...None.
Lake Huron...Gale Warning until 10 AM EDT Tuesday for LHZ361-362.

Small Craft Advisory until 10 AM EDT Tuesday for LHZ421-422-441>443.

Lake St Clair...Small Craft Advisory until 4 AM EDT Tuesday for LCZ460.

Michigan waters of Lake Erie...Small Craft Advisory until 4 AM EDT Tuesday for LEZ444.