A clearer picture.
One source at a time.

Start with the wind.

For Lake Michigan, wind speed and direction are the first things to watch. North Michigan adds offshore wind and waves; South Michigan Spotter and Rawley Point East add measured waves. Coastal stations provide local wind context.

Wind-only and wave-only stations are both useful. Wave height, period, and temperature appear when available, each with its own observation time. Missing does not mean zero.

Observed vs. forecast

Observations are measurements from a station at a particular place and time. They stay tied to that time even when you select a future forecast.

Forecasts are model or forecast-service estimates. “Now” means the forecast for the current hour, not a beach observation. Windy has its own independent forecast controls.

Station measurements older than two hours are marked stale. Forecasts retrieved over three hours ago, or whose latest refresh failed, are shown as stale and do not receive a rating. Retrieval time is when this app checked the source, not when the underlying model was run.

Local knowledge still matters

Offshore wave heights are not breaking-wave heights. Piers, shelter, wind shifts, and local exposure can change what you find at the water. The original spot notes are a starting point; dated field reports help fill in the picture.