Marine Weather Forecasts
Learning Goal 11a: Access the short-term and extended marine
forecast for a given location.
Students: For the final exam, just be aware of the main sources of marine weather info:
- Environment and Climate Change Canada (ECCC),
- NOAA Ocean Prediction Center (OPC),
- Continuous Maring Broadcasts (CMB),
- Weather Radio
and what types of info they provide. Do not memorize frequencies, phone numbers, channels, etc.
Environment & Climate Change Canada (ECCC)
Imagine you’re planning a trip to Saltspring Island for the long
weekend. First, you want to know what the weather is going to look
like. There are numerous resources available for forecasting the
weather. For recreational cruising on Canada’s coastlines, the marine
forecast provided by Environment & Climate Change Canada (ECCC)
is a good place to start. It can be found here: https://weather.gc.ca/marine/index_e.html
The ECCC forecast provides detailed forecast
information for the next 48 hours and a general forecast for the three
days thereafter. The page starts by listing the regions with weather
warnings in effect, then provides links to the remaining weather
conditions, with links to other forecasts (e.g. radar, satellite,
extended forecasts), weather alerts (e.g. hurricanes, public alerts),
and weather resources (e.g. astronomy, historical data).
Now, go to the ECCC (linked above). For a trip to
Saltspring Island, your region of interest will be the Pacific – South
Coast. First, check to see if there are any warnings in effect in your
region and then proceed to the next page where the region is broken
down into areas. This page is the same as the previous one, but with a
narrower spatial scale. For Saltspring, you would select ‘Strait of
Georgia – south of Nanaimo’. If there is a warning
in effect in your area, it will be bolded and in red across the top of
your areas weather forecast. For example, it might read “STRONG WIND
WARNING IN EFFECT” with a summary of when the warning starts and when
it is predicted to end (see image below for an example). Your extended
forecast will also be provided and usually extends 4 days ahead (see 11b for more
information on Weather Warnings ).
The focus of the marine forecast is wind direction and speed;
however, some locations will also have wave forecasts providing sea
height in meters. Storms or fog are also included in forecasts. Let’s
take a look at the Environment Canada’s forecast for the Strait of
Georgia south of Nanaimo:
You have northwesterly winds between 10 and 20 knots forecast for
the entire weekend. These are perfect wind conditions for a casual sail
across to the Gulf Islands! Conditions change however, and it is
important to monitor the weather while you’re on the water.
NOAA Ocean Prediction Center (OPC)
For voyages across the Pacific Ocean, a good place to start for an
overview of conditions is the Pacific Analysis weather map produced by
the Ocean Prediction Center (OPC) of the US National Oceanic and
Atmospheric Administratino (NOAA). You can find it at
https://ocean.weather.gov/Pac_tab.php .
Example of weather map for the eastern North Pacific Ocean. Source: https://ocean.weather.gov/P_e_sfc_color.png
We will learn how to read these weather maps in Learning Goal
11c. They show pressure, winds, fronts, lows, highs, typhoons,
troughs of low pressure (TROF), and weather warnings.
Additional sources of info across the Pacific are satellite
images. These will be discussed in more detail in Learning Goal
11d. They show clouds, from which we can infer locations of
fronts, highs, and lows.
Canadian Coast Guard Continuous Marine Broadcast (CMB)
The ECCC weather forecast for the entire Pacific
region is recorded by the Canadian Coast Guard and broadcast as a
continuous loop throughout the day on various radio frequencies. This
is called the Continuous Marine Broadcast
(CMB). The forecast is updated at 04:00, 10:30, 16:00, and 21:30. The
loop is also reset to the latest forecast at these times. The broadcast
cycles through the areas listed by ECCC and so you have
to be careful to listen for yours, otherwise you have to wait through
an entire loop before the forecast for your region is broadcast again.
Sailors can take advantage of the public weather alert system known as the
Weather Radio. The Canadian Weather Radio channels are in the table below.
Official
Name |
Frequency
(MHz)
|
Marine
Channel
|
Public Alert
(Weather Radio)
Channel
|
WX1 | 162.550 | 39B | 7 |
WX2 | 162.400 | 36B | 1 |
WX3 | 162.475 | 97B | 4 |
WX4 | 162.425 | 96B | 2 |
WX5 | 162.450 | 37B | 3 |
WX6 | 162.500 | 38B | 5 |
WX7 | 162.525 | 98B | 6 |
WX8 | 161.650 | 21B |
|
WX9 | 161.775 | 83B |
|
WX10 | 163.275 | 113B |
You can access the CBM via these VHF weather radio
channels while out on the water. Channels 1-7 are broadcast in both
English and French. Different areas use different frequencies, so you
have to know which frequency or channel pertains to the waters you are
in.
For example, the Vancouver area forecast is on channel 7
(frequency 162.550 MHz) and Victoria is on channel 1 (frequency 162.400
MHz).
In addition to the weather, the Canadian Coast Guard CMB also
tells you:
- Marine Communications and Traffic Service Centre Identification
(MCTS, who is providing the forecast)
- Distress and Urgency priority information (information regarding
the details of on-going marine incidents is broadcast to other
mariners)
- Ice formation
- Notices to shipping (announcing any hazards to navigation)
- Weekly mean water levels
You can also listen to the same audio recordings by telephone:
Served from the Prince Rupert MCTS Centre:
- Continuous Marine Broadcast (CMB) North & Central BC Coast: 250-624-9009
- Continuous Marine Broadcast (CMB) South Coast & Pacific side of Vancouver Island: 250-726-3415
Served from the Victoria MCTS Centre, for the Georgia Strait and Vancouver and Victoria areas:
- Continuous Marine Broadcast (CMB) Mount Helmcken: 250-363-6880
- Continuous Marine Broadcast (CMB) Bowen Island/Mount Parke: 250-363-6492
- Continuous Marine Broadcast (CMB) Bowen Island/Mount Parke: 604-666-3655
- Continuous Marine Broadcast (CMB) Mid Island Area: 250-339-0748
- Continuous Marine Broadcast (CMB) North Island Area: 250-974-5305
Other Weather Resources
Environment Canada’s Marine Weather Forecast should be your first
stop for weather information. However, there are several alternative
weather resources available to you. The more you know about the
conditions you will be sailing in, the better, so look around online,
review multiple weather forecasts, read the forums, and make informed
decisions. Here are a just a few to get you started:
Additional Resources: (non-required material)
Environment Canada’s Marine Forecast and Warnings for Canada: http://www.weather.gc.ca/marine/index_e.html
Guide to Environment Canada Marine Weather Forecasts: http://www.ec.gc.ca/meteo-weather/default.asp?lang=En&n=2EC4EC51-1
Videos: