Marine Weather and Tide Forecast for Detroit Beach, MI

AVIATION

Well-mixed and gusty SW surface wind has spread into Lower Mi in warm sector fashion ahead of low pressure occluding into the northern Great Lakes. The associated cold front sweeps remaining thunderstorm potential into Ontario by the 06Z forecast issuance leaving a few hours of VFR in the system dry slot during the late night. This precedes MVFR ceiling as it expands eastward from the Midwest where coverage is widespread around the SW flank of the surface low center. Gusty wind also becomes a weather highlight late tonight and especially as daytime instability builds by late morning through the afternoon. West gusts well in into the 30 knot range are expected which also helps ceiling break into low end VFR late in the day and Saturday evening.

For DTW/D21 Convection... Thunderstorms move east of the DTW terminal area from 06Z onward late tonight.

THRESHOLD PROBABILITIES...

* Low for ceiling 5000 feet or less late tonight the high in the morning through Saturday evening.

PREV DISCUSSION
Issued at 943 PM EDT Fri May 16 2025

UPDATE...

Ongoing storms from central Lower Mi into southern Lake Mi continue moving eastward while new development is likely out ahead and farther east into SE Mi late this evening. Expanding convection is boosted by height falls and DCVA on the leading edge of the 500 mb low which then feed off MUCAPE holding in the 1000-1500 J/kg range and effective bulk shear in the 30-50 kt range. This has already been supportive of the large hail producing supercell exiting Isabella county at forecast issuance. Hourly mesoanalysis and RAP projections maintain favorable 700-500 mb lapse rate near 8 C/km as the moisture axis sweeps through Lower Mi ahead of the cold front.
This is combined with the 00Z DTX sounding that shows both the lapse rate and dry air centered around 700 mb along with a dry inverted-V profile below cloud base. Bottom line here is that we continue to expect strong to severe storms, with large hail as the primary hazard and damaging wind also possible, in SE Mi until the cold front sweeps activity into Ontario around 2 AM.

PREV DISCUSSION...
Issued at 344 PM EDT Fri May 16 2025

DISCUSSION...

Southeast Michigan holding position late this afternoon immediately downstream of a closed mid level pivoting across Wisconsin. A warm but drier profile now entrenched, with a brief window of deeper stability in residence now evident by a simply a limited coverage of diurnal cu. Dry and stable conditions to hold through at least 00z, with attention tonight shifting to a mid level perturbation shearing out ahead of the main height fall center. Noted increase in forced ascent attendant to this feature set to sweep across the local area 01z-07z. Renewed boundary layer moistening will commence at the same time, offering at least a weakly unstable low level environment.
Mixed signal yet across the model solution space on possible degree of destabilization, with variability noted in dewpoint recovery by as much as 8-10 degrees. This will impact both prospective coverage and vigor of any convective development within this window. Assuming the upward vertical motion field can overcome residual capping issues, then potential exists for cells to attain greater updraft depth given very steep mid level lapse rates. Background wind field more than sufficient to offer organization to any vigorous updrafts.
This conditional setup carries enough potential should greater instability materialize to warrant an upgrade in the Day 1 SPC outlook to a slight risk for southern portions of the area, highlighting a damaging wind gust and hail threat. A secondary window exists for sub-severe convective development with the actual cold frontal passage late tonight.

Mid level low offers greater influence on conditions to start the weekend, with the circulation center passing thru northern lower MI during the daylight hours Saturday. Cold front exits to the east Saturday morning, with ensuing cold air advection battling daytime heating throughout the day. Minimal thermal recovery expected off morning lows. Temperatures parked in the upper 50s to lower 60s.
Notably breezy conditions as mixing capitalizes on a firm west- southwest gradient. Gusts in excess of 30 mph Saturday afternoon.
Moist cyclonic flow engaging daytime heating will maintain a chance of showers. Seasonably cool conditions persist Sunday under deeper layer northwest flow. Aside from a broad, thicker diurnal stratocu field, generally benign weather conditions to finish the weekend as general subsidence takes control.

Cooler and drier profile maintains residence Monday as low level northeast flow governs conditions under building high pressure from the north. A high amplitude, slowly evolving large scale pattern emerges for the midweek period. Southeast Michigan likely holds position between the high to the north and organizing low pressure to the west. Potentially unsettled conditions at times this period, depending the pace and trajectory of the closed low. Maintenance of east flow with prospective cloud/shower potential on the rise will keep temperatures on the cooler side of average through the rest of the week.

MARINE...

Low pressure tracks over Lake Superior this evening sweeping a respectable cold front late this evening. A broken line of showers and storms likely develops in advance with isolated embedded strong to severe thunderstorms possible. Moderate west-southwest winds follow Saturday with the strongest winds (20-30kts) expected over the southern half of the region where the gradient is strongest.
Small craft advisories have been issued for all nearshore waters daytime Saturday as a result. Low fully departs Sunday shifting winds to the northwest. Gusts peak near 20kts during the day before weakening overnight as weak high pressure slides overhead.

DTX WATCHES/WARNINGS/ADVISORIES

MI...None.

Lake Huron...Small Craft Advisory from 8 AM to 10 PM EDT Saturday for LHZ421-422- 441>443.

Lake St Clair...Small Craft Advisory from 8 AM to 10 PM EDT Saturday for LCZ460.

Michigan waters of Lake Erie...Small Craft Advisory from 8 AM to 10 PM EDT Saturday for LEZ444.