Marine Forecast
Illustrated map of Grand Traverse Bay

Marine forecast

Harbor Beach to Port Sanilac, MI

current wind
18 kt W
Gusts
23 kt
Seas
1.0 ft
Period
3 sec
Air
80°F

Observed Tue 2:54 PM | LHZ442

Gusts now
23 kt
Seas now
1.0 ft · 3 sec
Air
80°F
Water
61°F
72-hr peak
27 kt

In brief

At 2:54 pm EDT on Oct 13, 2026, NDBC station HRBM4 (Harbor Beach, MI, 14 miles away) measured wind from the W at 18 kt, gusting to 23 kt; buoy 45149 measured seas of 1.0 ft. The NWS forecast for Harbor Beach to Port Sanilac, MI issued at 9:53 am EDT on Oct 13, 2026 reads, for rest of today: “Southwest winds 15 to 20 knots veering to the west late in the afternoon. Mostly sunny.” A Small Craft Advisory is in effect until Tue 8:00 PM.

Source: National Weather Service Detroit/Pontiac MI forecast; NDBC observations

Wind forecast · ktPeak 27 kt

05101520253035Wed 14Thu 15Fri 1605101520253035Wed 14Thu 15Fri 16
Sustained GustOct 13-16 | EDT

Seas forecast · ftPeak 3 ft

0123Wed 14Thu 15Fri 160123Wed 14Thu 15Fri 16
Oct 13-16 | EDT

Marine advisory

Small Craft Advisory in effect for Harbor Beach to Port Sanilac until Tue 8:00 PM.

Full text of this small craft advisory

* WHAT...Expect sustained winds up to 18 knots from the west with gusts up to 25 knots. The largest significant waves will be 3 feet with a potential maximum wave height of 4 feet. * WHERE...Outer Saginaw Bay SW of Alabaster to Port Austin MI to Inner Saginaw Bay, Inner Saginaw Bay SW of Point Au Gres to Bay Port MI, Port Austin to Harbor Beach MI, Harbor Beach to Port Sanilac MI and Port Sanilac to Port Huron MI. * WHEN...The maximum winds are expected around 12 PM EDT Tuesday with the largest waves expected around 4 PM EDT Tuesday. * IMPACTS...Conditions will be hazardous to small craft.

NWS marine forecast

PeriodForecast
Rest Of TodaySouthwest winds 15 to 20 knots veering to the west late in the afternoon. Mostly sunny. Waves 1 to 3 feet.
TonightNorthwest winds 15 to 20 knots diminishing to 5 to 10 knots. Partly cloudy becoming mostly cloudy in the late evening and early morning becoming partly cloudy. Waves 1 to 3 feet.
WednesdayNorthwest winds 10 to 15 knots. Mostly cloudy early in the morning becoming partly cloudy. Waves 1 to 3 feet.
Wednesday NightNorth winds 15 to 20 knots becoming northeast 10 to 15 knots after midnight. Partly cloudy early in the evening becoming mostly cloudy. Waves 2 to 4 feet. See Lake Huron Open Lake Forecast for days 3 through 5.

Issued Tue 9:53 AM by Detroit/Pontiac MI (product NSHDTX).

TimeWindGustSeasWater
Tue 2:54 PM 18 kt W 23 kt — 61°F
Tue 1:54 PM 13 kt WSW 21 kt — 61°F
Tue 12:54 PM 12 kt W 20 kt — 61°F
Tue 11:54 AM 14 kt WSW 22 kt — 61°F
Tue 10:54 AM 12 kt WSW 17 kt — 61°F
Tue 9:54 AM 8 kt SW 14 kt — 61°F
Tue 8:54 AM 8 kt SW 9 kt — 61°F
Tue 7:54 AM 7 kt SSW 10 kt — 61°F
Tue 6:54 AM 5 kt S 6 kt — 61°F
Tue 5:54 AM 5 kt S 6 kt — 61°F
Tue 4:54 AM 9 kt S 10 kt — 61°F
Tue 3:54 AM 0 kt 1 kt — 61°F

Observed Tue 2:54 PM at NDBC buoy HRBM4 (Harbor Beach, MI), 14.5 miles away. Seas from buoy 45149 (Southern Lake Huron), 26.2 miles away, at Tue 3:00 PM.

What is the marine forecast for Harbor Beach to Port Sanilac today?

Rest Of Today: Southwest winds 15 to 20 knots veering to the west late in the afternoon. Mostly sunny. Waves 1 to 3 feet.

Is there a small craft advisory for Harbor Beach to Port Sanilac?

Yes — small craft advisory in effect until Tue 8:00 PM.

How high are the waves at Harbor Beach to Port Sanilac right now?

Seas are running 1.0 ft at a 3-second period, measured at NDBC buoy HRBM4 Tue 2:54 PM, 14.5 miles from this zone. The forecast peaks at 3.0 ft Fri 1 PM.

What is the water temperature at Harbor Beach to Port Sanilac?

The nearest buoy read 61°F (16°C) at Tue 2:54 PM. Sea surface temperature at a single buoy can differ by several degrees from the water at a beach or in a shallow bay nearby.

What do the wind speeds in knots mean?

One knot is 1.15 mph. The National Weather Service issues a small craft advisory for sustained winds of roughly 22–33 knots or hazardous seas, a gale warning at 34–47 knots, and a storm warning at 48 knots and above. Exact advisory thresholds vary by forecast office and by water body — a bay reaches dangerous chop at a lower wind speed than open ocean.

Where does this forecast come from?

The forecast text is the National Weather Service's own marine bulletin for zone LHZ442, issued by Detroit/Pontiac MI, reproduced in full. The wind and seas charts are drawn from the NWS gridded forecast for a point inside the zone. Observations come from the nearest reporting NDBC buoy. We are not affiliated with NOAA or the National Weather Service.

Forecast: NOAA/NWS product NSHDTX, issued Tue 9:53 AM. Observations: NOAA National Data Buoy Center station HRBM4, read Tue 2:54 PM. Retrieved Oct 13, 3:42 PM. Conditions offshore change faster than any page can be rebuilt, so check the current NWS bulletin and your own instruments before going out.