Marine forecast
Saginaw Bay: Alabaster–Port Austin / Inner Bay
- current wind
- 21 kt WSW
- Gusts
- 25 kt
- Seas
- 1.0 ft
- Period
- 3 sec
- Air
- 74°F
Observed Tue 2:40 PM | LHZ421
- Gusts now
- 25 kt
- Seas now
- 1.0 ft · 3 sec
- Air
- 74°F
- 72-hr peak
- 31 kt
- Peak seas
- 5 ft
In brief
At 2:40 pm EDT on Oct 13, 2026, NDBC station GSLM4 (Gravelly Shoal Light, MI, 9 miles away) measured wind from the WSW at 21 kt, gusting to 25 kt; buoy 45149 measured seas of 1.0 ft. The NWS forecast for Saginaw Bay: Alabaster–Port Austin / Inner Bay, 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 late in the morning becoming partly cloudy.” 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 31 kt
Seas forecast · ftPeak 5 ft
Marine advisory
Small Craft Advisory in effect for Saginaw Bay: Alabaster–Port Austin / Inner Bay 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
| Period | Forecast |
|---|---|
| Rest Of Today | Southwest winds 15 to 20 knots veering to the west late in the afternoon. Mostly sunny late in the morning becoming partly cloudy. Waves 2 to 4 feet. |
| Tonight | Northwest winds 15 to 20 knots diminishing to 10 to 15 knots in the late evening and overnight. Partly cloudy early in the evening becoming mostly cloudy. Waves 1 to 3 feet. |
| Wednesday | Northwest winds 10 to 15 knots. Mostly cloudy becoming partly cloudy in the late morning and early afternoon becoming mostly cloudy. Waves 2 feet or less. |
| Wednesday Night | North winds 15 to 20 knots becoming northeast 10 to 15 knots after midnight. Partly cloudy until early morning becoming mostly cloudy. Waves 1 to 3 feet building to 2 to 4 feet in the late evening and overnight. See Lake Huron Open Lake Forecast for days 3 through 5. |
Issued Tue 9:53 AM by Detroit/Pontiac MI (product NSHDTX).
Recent buoy conditions
| Time | Wind | Gust | Seas | Water |
|---|---|---|---|---|
| Tue 2:40 PM | 21 kt WSW | 25 kt | — | — |
| Tue 1:50 PM | 15 kt SW | 16 kt | — | — |
| Tue 12:50 PM | 16 kt SSW | 16 kt | — | — |
| Tue 11:50 AM | 13 kt SSW | 14 kt | — | — |
| Tue 10:50 AM | 4 kt SW | 5 kt | — | — |
| Tue 9:50 AM | 9 kt SW | 10 kt | — | — |
| Tue 8:50 AM | 10 kt SW | 13 kt | — | — |
| Tue 7:50 AM | 9 kt SSW | 10 kt | — | — |
| Tue 6:50 AM | 0 kt | 3 kt | — | — |
| Tue 5:50 AM | 8 kt SE | 9 kt | — | — |
| Tue 4:50 AM | 9 kt ESE | 10 kt | — | — |
| Tue 3:50 AM | 12 kt E | 13 kt | — | — |
Observed Tue 2:40 PM at NDBC buoy GSLM4 (Gravelly Shoal Light, MI), 8.8 miles away. Seas from buoy 45149 (Southern Lake Huron), 71.1 miles away, at Tue 3:00 PM.
Frequently asked questions
What is the marine forecast for Saginaw Bay: Alabaster–Port Austin / Inner Bay today?
Rest Of Today: Southwest winds 15 to 20 knots veering to the west late in the afternoon. Mostly sunny late in the morning becoming partly cloudy. Waves 2 to 4 feet.
Is there a small craft advisory for Saginaw Bay: Alabaster–Port Austin / Inner Bay?
Yes — small craft advisory in effect until Tue 8:00 PM.
How high are the waves at Saginaw Bay: Alabaster–Port Austin / Inner Bay right now?
Seas are running 1.0 ft at a 3-second period, measured at NDBC buoy GSLM4 Tue 2:40 PM, 8.8 miles from this zone. The forecast peaks at 5.0 ft Fri 3 PM.
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 LHZ421, 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 GSLM4, read Tue 2:40 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.