Friday, 30 March 2018

Detailed description of British Columbia marine weather (Free download)

Environment Canada, Canada's national weather forecaster, provides this detailed, highly informative guide to weather patterns on the B.C. coast, including helpful tips for mariners.

Sample page covering Kelsey Bay (Johnstone Strait) winds

It has been "archived", so not all that easy to search for; here is the direct link to the pdf file (click to download):

IF the above link is broken, use this link to download:


  1. This is really helpful. I hadn't heard of or seen this before. We're cruising BC currently and I'm learning from this PDF intricacies of the weather patterns that are beyond what I imagined.
    If Environment Canada understands the Georgia basin so well (the "bathtub effect", local wind effects, etc) I wonder why they don't do marine point forecasts like the US does, or give more granularity to their forecasts (US wind forecasts are more granular in both time window and magnitude of wind strength).

    1. Thanks for your comment Patrick.

      My question about the NOAA "point" forecasts: are they simply from computer models and without human forecaster input (this seem likely the case)? As such, they do not take into account land affects such as those at points of land, katabatic winds, etc. So common here in BC waters.

      Such "point" forecasts are indeed available for BC waters from many apps and websites (e.g., windyty) but these are only based on computer models and not so useful for routes such as the Inside Passage, etc.

    2. I believe NOAA point forecasts are model based, but WindyTy is too and certainly appears to take into account land interactions to some extent. We find Windy and PredictWind GRIBs to be much more accurate and detailed than Env Canada forecasts (but can only get VHF forecasts when we're out of cellular tower range).

      Mainly my unexpected takeaway from the doc was that Env Canada researchers know much more about the wind than they put into the forecasts. I guess the answer is always one of govt funding, and it's hard to change a system once it's in place.

    3. GRIBS don't take into account local land effects.

      I cannot answer regarding Environment Canada marine forecasts for the whole BC coast, but most certainly their forecasts for the South Coast involve human forecasters (these forcasts DO differ from the gribs)

      We use our HAM/SSB with Pactor modem to get forecasts (and gribs) when out of cell and VHF range of Environment Canada VHF forecasts.


  2. As for the "detail" provided by GRIB-based forecasts such as Windyty and Predictwind, such detail is questionable at the local scale, especially when weather will be significantly impacted by local land effects, tidal currents, etc.

    Environment Canada has a fee-based access to local detailed forecasts from forecasters. Likely beyond my meanns: Forecast Consultation Service (user fees apply): 1-900-565-6565 (direct billing) or 1-888-292-2222 (cellphone access, credit card account billing)

    You can contact them via their website and ask them specifically about their marine forecasts: