Version 2, updated August 2026. This revision leads with Environment Canada's high resolution models for Canadian Great Lakes water, adds a section on waves, and repositions ECMWF as a trend model rather than a day-of tool. The original version was published in November 2025.
We all check the weather before we go paddling. Most of us bounce between the Weather Network, a few apps, and Windy. The challenge is knowing what to trust when they do not agree. At Kayak Ontario we run almost everything through Windy, but not the way it comes out of the box. This is how we use it.
Who's the Boss
Environment Canada is the boss. On Canadian water their marine forecast sets the boundary for the day. On the US side of the lakes, NOAA does the same job. It gives you the worst case, the big picture, and the conditions you plan around. It is also the layer that carries the small craft, strong wind, and gale warnings. Windy does not replace this. It refines inside it.
The Part Most Paddlers Miss
Windy opens on ECMWF, the global model from the European Centre for Medium-Range Weather Forecasts. Windy uses it as the default for a good reason: it is one of the most accurate global models in the world, which is exactly why so many paddlers trust it and stop there. ECMWF is excellent, but its grid is around 9 km, which is too coarse to see what the wind actually does in a single bay on the Great Lakes. If you read the default and launch on it, you are planning your local day on a global picture. The skill is knowing which model to switch to, and when. Everything below is a model you select inside Windy.
HRDPS, your day-of wind model
HRDPS, short for High Resolution Deterministic Prediction System, is Environment Canada's high-resolution model at 2.5 km, and it is built into Windy. For Canadian Great Lakes water it is the best wind read available. That resolution is fine enough to resolve the channel and peninsula funneling that decides whether a crossing is on, the exact local effect ECMWF smooths away. When we are making a day-of call on Georgian Bay or the Bruce, this is the model we switch to first.
HRRR, your second high-resolution opinion
HRRR, the High-Resolution Rapid Refresh, is a 3 km, radar-assimilated model that updates every hour, also in Windy. It reacts fast to lake breezes, squalls, and shoreline effects, and it is strong for gusts and convective signals. We run it alongside HRDPS right before launch. When the two high-resolution models agree, confidence is high. When they split, that disagreement is itself information.
ECMWF, the default, but use it for the trend
ECMWF is the model Windy hands you first, and it has real value, just not for local wind. Use it for the synoptic pattern and the multi-day trend: where the systems are and whether the next few days are stable or unsettled. When ECMWF and the marine forecast agree on the pattern, confidence in the week is high. Plan the week on ECMWF. Call the day on HRDPS.
GFS, the global cross-check
GFS, the Global Forecast System, is the other global model in Windy, also useful for the broad pattern rather than local detail. If GFS, ECMWF, and the marine forecast all agree, the day is usually stable. If GFS disagrees, the larger pattern is uncertain and you plan conservatively.
Waves: Switch the Layer Too
The wind models above do not give you waves. Windy has a separate wave layer, and on the Great Lakes it also opens on a global ocean model. That physics is wrong for closed, shallow basins like Georgian Bay and Lake Huron, so the wave height it shows you by default is not trustworthy here. Switch the wave layer to RDWPS, the Regional Deterministic Wave Prediction System, Environment Canada's wave model built for this water and driven by the same HRDPS winds you are already reading. One more thing the model will not tell you: every wave height is an open-water number. Reefs, crossings, and wind against current can build something steeper and more dangerous close to shore than the grid suggests.
A Simple Process That Works
This is the same system we teach in our Level 2 courses. It keeps things practical and stops you from getting lost in the weeds.
- Start with the official marine forecast, that is your boundary
- Open Windy and switch off the default: HRDPS for wind, RDWPS for waves
- Read the gust row, not just the mean wind
- Check it against real observations from a buoy and a nearby land station
- Look for the pattern: building, easing, backing, veering
- Write a brief plain-language synopsis you can actually use
- Plot your expected wind vectors on your chart with a dry erase marker and plan your route
This is how you build confidence. When you start to see patterns, forecasting becomes a lot less mysterious and your decisions become more informed.
From Our Level 2 Course
This is a short snippet from the online portion of our Level 2 program. The goal is not to turn you into a meteorologist. It is to help you read the day in a way that feels predictable and practical on the water.
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