Guide to marine weather forecasts: chapter 4

What information is included in the Marine Forecast?

Day 1 and Day 2 (Regular and Wave Height Forecasts)

The regular marine forecast will contain the following marine weather elements:

• Wind: Wind direction expressed in one of eight cardinal directions of the compass, and speed expressed in knots or, if winds are light, this will be stated - “Wind light.”
• Weather conditions, precipitation, and visibility: Included if the weather condition or precipitation is expected to pose an obstruction to visibility equal to or less than 1 nautical mile.
• Freezing spray: Included if moderate or severe freezing spray is forecast.
• Air temperature: Included if the air temperature range reaches or crosses the zero degrees Celsius threshold. Note that marine forecasts for Ontario Region do not include air temperatures. 

The wave height forecast includes the following:

• Wave height : Stated in meters, unless forecast waters are ice-covered. If forecast waters are ice-covered then this will be stated - “Seas mostly ice-covered.”

Days 3, 4 and 5 (Extended Marine Forecast)

The extended marine forecast includes the following:

• Wind: Wind direction expressed in one of eight cardinal directions of the compass, and speed expressed in knots or, if winds are light, this will be stated - “Wind light.”