Guide to marine weather forecasts: chapter 10

Marine Warnings and Watches Program

The Marine Warning and Watches Program provides advisories to mariners or marine interests to inform them of marine weather conditions that may pose a hazard to their safety, security, or operations.

Marine warnings and watches are issued year round, or during the shipping season where forecast waters may close seasonally due to the presence of ice. Marine warnings or watches are issued whenever criteria are met or expected to be met during the valid period of the regular or updated forecast.

Although warnings or watches are not issued for anticipated marine weather events which occur beyond the regular or updated marine forecast time period of coverage, marine weather statements may be issued to provide further detail regarding potentially high impact marine weather events expected to occur during the extended marine forecast time period of coverage.

Marine warnings and watches fall into two main categories: (1) synoptic warnings and (2) localized warnings & watches. Another category of warnings include the ice warnings of which the Canadian Ice Service is the responsible issuing agency.