Marine Weather and Tide Forecast for Grand Haven, MI

DISCUSSION
Issued at 229 AM EDT Thu Apr 16 2026

- Lingering Showers and Storm Into Afternoon, Continued Flooding

Thunderstorms have exited the area, leaving areas of rain. Additional storms are noted upstream across southern WI. Although the vast majority of expected precipitation has fallen already, there is a signal in some of the convection allowing models that localized bands of a quick additional half inch or so are possible in some spots before the rain fully exits this afternoon.

- Dry Friday, Rain and Thunderstorms Friday Night into Saturday

After a dry and warm Friday with highs in the 70s, we will experience deep southwesterly lower tropospheric flow in response to an approaching sharp upper trough. SPC does advertise a Day4 (12Z Sat to 12Z Sun)
risk for severe weather that reaches into SE Lower MI, and this is corroborated by several of the medium range AI models. This will depend in large part on frontal timing. Predictability for this might actually be relatively good due to the highly phased and especially prominent nature of the upper trough and associated low level baroclinic zone.

- Colder and Windy Sunday

Colder air moves in behind the low Saturday with low temperatures Saturday night into Sunday dropping into the upper 20s to 30s. Breezy west to northwest winds will cause wind chills to be in the 20s Sunday morning. Highs are expected to make it into the 40s, but this will still feel quite brisk with the winds and coming off a prolonged period of unseasonable warmth.

- Dry Early Next Week

Northwesterly flow aloft in the wake of the exiting upper low will yield dry conditions with a gradual warmup. Some of the deterministic model solutions show an upper PV max brushing the northern Great Lakes, but precipitation chances remain in question due to scarcity of low level moisture. The odds currently favor a dry forecast into and including Wednesday, but this could change. The good news is that any precipitation that occurs should be far less impactful than what has been experienced this week.

AVIATION /06Z TAFS THROUGH 06Z FRIDAY/
Issued at 1255 AM EDT Thu Apr 16 2026

Showers and thunderstorms are moving eastward across the area as a frontal boundary traverses Michigan. An additional line of showers and thunderstorms will reach KMKG later in the morning, followed by terminals further to the south and east in the afternoon. Periods of IFR to LIFR conditions are possible as the storms reach the terminals. Lower clouds will remain in the area after the storms pass, which means MVFR conditions will persist into the early evening. Increased southwesterly winds also pick up in the late morning through early afternoon along and south of Interstate 96, with peak gusts around 20 knots possible. Winds should decrease through the rest of the afternoon and evening.

MARINE
Issued at 229 AM EDT Thu Apr 16 2026

In coordination with MKX, have extended the Marine Dense Fog Advisory until Friday morning. As noted previously, we expect increasing winds and waves to become hazardous to small craft beginning Friday night.

HYDROLOGY
Issued at 250 PM EDT Wed Apr 15 2026

Bottom line: The most significant flood in recent years continues to develop along the Muskegon River. Meanwhile, heavy rains last night are also likely now going to create another round of primarily minor flooding along the Grand River and associated tributaries.

Another 1.5 to 2.5 inches of rain fell last night across a large portion of the area, with the exception of the headwaters areas of the Grand, Muskegon, and Kalamazoo watersheds (where closer to 1 inch of rain fell). Unfortunately, another 0.5 inches is expected tonight and tomorrow across a large area, with localized streaks of 1 to 3 inches.

Along with the river flooding, urban and low lying areas will be prone to flooding due to any additional thunderstorms rains in the next day or so.

Further south, the Kalamazoo River has been a bit drier lately, so no flooding is expected to develop there, though urban and poor- drainage area flooding will definitely be possible into Thursday as additional rounds of thunderstorms move through.

GRR WATCHES/WARNINGS/ADVISORIES
MI...Flood Watch through late tonight for MIZ037>040-043>046-050>052- 056>059-064>067-071>074.
MARINE...Dense Fog Advisory until 8 AM EDT Friday for LMZ845>849.