Marine weather products and services: Hudson, Mackenzie and Arctic waters

Available Forecast Products

Note: The following forecast products are available only during the “open water” season.

The Regular Forecast, or short-term marine forecast, is issued twice per day and covers the current day and the next day. It includes detailed information on winds, and a general description of weather conditions. It also includes any wind and freezing spray warnings in effect at the time.

  • Issue Times - Mackenzie River & Lake Athabasca: Mountain Daylight Time / Mountain Standard Time (MDT/MST): 5:00 a.m.; 5:00 p.m.
  • Issue Times - Western Arctic Waterway (MDT/MST): 7:00 a.m.; 7:00 p.m.
  • Issue Times - Arctic: Eastern Daylight Time / Eastern Standard Time (EDT/EST): 5:30 a.m.; 5:30 p.m.
  • Issue Times - Hudson Bay: Central Daylight Time / Central Standard Time (CDT/CST): 5:00 a.m.; 5:00 p.m.
  • Issue Times - Southern Nunavut (EDT/EST): 5:30 a.m.; 5:30 p.m.
  • Issue Times - Eastern Nunavut (EDT/EST): 5:00 a.m.; 5:00 p.m.
  • Issue Times - High Arctic (EDT/EST): 5:00 a.m.; 5:00 p.m.

The Extended Forecast is issued twice per day and covers the period from the end of the Regular Forecast to the end of the fifth day of the forecast period (days three to five). It includes only a general description of expected wind conditions.

  • Issue Times - Mackenzie River & Lake Athabasca (MDT/MST): 5:00 a.m.; 5:00 p.m.
  • Issue Times - Western Arctic Waterway (MDT/MST): 7:00 a.m.; 7:00 p.m.
  • Issue Times - Arctic (EDT/EST): 5:30 a.m.; 5:30 p.m.
  • Issue Times - Hudson Bay (CDT/CST): 5:00 a.m.; 5:00 p.m.
  • Issue Times - Southern Nunavut (EDT/EST): 5:30 a.m.; 5:30 p.m.
  • Issue Times - Eastern Nunavut (EDT/EST): 5:00 a.m.; 5:00 p.m.
  • Issue Times - High Arctic (EDT/EST); 5:00 a.m.; 5:00 p.m.

The Technical Marine Synopsis is issued twice per day and covers the current day and the next day. It gives a general picture of the position, intensity and motion of the main weather features (lows, highs, fronts) that will affect the region during the forecast period.

  • Issue Times - Western Arctic (MDT/MST): 6:30 a.m.; 6:30 p.m.
  • Issue Times - Central Arctic (MDT/MST): 6:30 a.m.; 6:30 p.m.
  • Issue times - Hudson Bay and Eastern Arctic (EDT/EST): 4:45 a.m.; 4:45 p.m.

The Marine Weather Statement is a non-scheduled bulletin which is issued to inform the marine community of non-severe, but potentially hazardous, conditions. It may also be issued to warn mariners of very significant weather features expected in the three to five day forecast.

The Wave Height Forecast is issued twice per day and covers the current day and the next day. This forecast describes the expected significant wave height rather than the maximum wave height. Significant wave height is defined as the average of the highest one-third of all waves. Wave heights are described in metres and are measured from trough to crest.

  • Issue Times - Western Arctic Waterway (MDT/MST): 7:00 a.m.; 7:00 p.m.
  • Issue Times - Arctic (EDT/EST): 5:30 a.m.; 5:30 p.m.
  • Issue Times - Hudson Bay (CDT/CST): 5:00 a.m.; 5:00 p.m.
  • Issue Times - Southern Nunavut (EDT/EST): 5:30 a.m.; 5:30 p.m.
  • Issue Times - Eastern Nunavut (EDT/EST): 5:00 a.m.; 5:00 p.m.
  • Issue Times - High Arctic (EDT/EST): 5:00 a.m.; 5:00 p.m.

The NAVTEX Forecast is a shortened version of the above marine forecast products which is transmitted by the Canadian Coast Guard by NAVTEX. This forecast is intended for international mariners travelling in Canadian waters.

  • Issue Times - Iqaluit VFF (EDT/EST): 5:30 a.m.; 5:30 p.m.

Ice Hazard Bulletins are issued once daily and cover the current day and the next day. These bulletins contain information on ice conditions and include any warnings related to sea ice. Detailed ice information is available on Environment Canada's weather Website at http://.weather.gc.ca.

  • Issue Times - Western and Central Arctic (EDT/EST): 10:00 a.m.
  • Issue Times - Hudson and Foxe (EDT/EST): 11:00 a.m.
  • Issue Times - Eastern and Northern Arctic (EDT/EST): 11:00 a.m.

Note: Updated forecasts are issued as required.

What is Included in a Marine Forecast?

Wind Speed and Direction: The wind speed is the average wind that is expected over the open water and is given in units of knots (1 kt = 1.852 km/h). Wind direction refers to the direction from which the wind is blowing. The wind direction is based on true north and not on magnetic north. Wind conditions close to shore may vary from the forecast winds due to the influence of coastal terrain on the prevailing wind pattern.

Weather and Visibility: In addition to a brief description of the weather, a statement is included in the forecast when visibility is expected to be reduced to near or below one nautical mile (1.852 km).

Freezing Spray: Freezing spray is mentioned in the forecast if conditions are likely to result in ice build-up on exposed vessel surfaces.

Air Temperature: Air temperatures are included in the forecast only if temperatures are expected to be at or below 0° Celsius.

Marine Weather Warnings

Wind Warnings are included in the Regular Forecast when wind speeds are expected to be in the following categories:

  • Strong Wind Warning 20-33 knots (Issued only for the Mackenzie River, Lake Athabasca and Great Slave Lake)
  • Gale Warning 34-47 knots
  • Storm Warning 48-63 knots
  • Hurricane Force Wind Warning 64 knots or greater (This warning does not mean that an actual hurricane is expected or occurring.)

Freezing Spray Warnings are issued when ice is expected to build up at a rate of 0.7 cm per hour or greater. 

Note: Strong Wind, Gale, Storm, Hurricane Force Wind and Freezing Spray Warnings are not issued as separate warning bulletins. Rather, they are mentioned or "flagged" in the Regular Forecast.

Localized Warnings and Watches are issued for any hazardous weather conditions that require the immediate attention of the mariner. High coastal waters, for example, would require a specialized warning. These warnings/watches are issued as separate warning bulletins, and except for the High Water Level Warning, they are not included as part of the Regular Forecast.

How to Get Your Marine Forecast

For complete details about how to get the marine forecast information from Environment Canada in your area, visit our Get Your Weather page and learn more about the various ways to obtain the information you need. 

Environment Canada's marine weather forecasts are also available via the Canadian Coast Guard's Continuous Marine Broadcast on your VHF radio. For information about Coast Guard’s weather broadcast frequencies in your area, visit Coast Guard’s most current Radio Aids to Marine Navigation publication.

Report a problem or mistake on this page
Please select all that apply:

Thank you for your help!

You will not receive a reply. For enquiries, contact us.

Date modified: