I have a really hard time trusting meteorologists.
No offence is intended to any weather forecasters who are reading this. The trouble is, Kingston is a geographically and meteorologically complex region, making it hard to build accurate forecast models with sufficiently fine detail- and the forecasters who do cover our area are also responsible for many, many other cities. So, while a forecast of "sunny, not much happening" is pretty reliable, estimates of wind, rain and sea state are often way off.
When we're heading out on Lake Ontario, therefore, we never rely on just one forecast. If three or four different forecasts are in agreement, we'll take that as a good sign.
Here's our usual weather prediction strategy for Lake Ontario. Keep in mind that we mainly do short trips of a few hours to a day, and that I'm talking about very small powerboats that can knock off the miles quickly but can't handle storm conditions.
Deciding when to go
We keep an eye on the 5, 7 and 14 day forecasts from the big three weather services:
When all three agree that a particular day will be free of storms and is likely to be warm and not too windy, we'll call up some friends and plan to head out on that day.
Deciding where to go
On the day before (or the morning of) a trip, we'll check the aforementioned forecast services, and also pull up some more detailed data:
- Wind and wave forecast model data from PassageWeather
- Raw satellite imagery from WXSat
- Radar, satellite, ground station and model data on Wunderground
If, at this point, anyone is forecasting a storm, we'll call off the trip. Otherwise, it's time to compare the forecast data to the nautical charts and decide where we want to go. The nature of small boat travel is that your destinations will be dictated by the weather. If there's a west wind, for example, the head of Wolfe Island is out of reach; even a light wind can build up substantial chop over a 50-mile fetch. On the Rideau Canal, by contrast, we can stay comfortable and dry even in fairly substantial winds; there is simply no room for waves to build up.
The main thing we're interested in is the wind. Is there general agreement on where the wind will be coming from, and at what strength? Four models all calling for a 10 km/h westerly are likely reliable. If one calls for 5 km/h E, two say 8 km/h S, and one says 6 km/h NW, there's a good chance they're all wrong and it'll actually be 25 km/h W. (We actually had that exact situation a bit over a week ago... it made for a pretty wet trip back from Wolfe Island.)
We also look at the radar and satellite data to see what cloud systems are coming. In a small open boat, there is nowhere to take shelter if it rains, and nothing to protect you if a thunderstorm hits. Any tall, dense cloud systems coming from the west will get the trip called off. Lesser cloud systems may have us change destinations- gunkholing up the rivers, perhaps, instead of heading out to the open lake.
Updates on the water
Environment Canada's continuous broadcasts on the WX channels (available on most marine VHF sets) are a great source of up-to-date data. The best weather information of all, though, comes from keeping an eye on what's going on around you. Is the wind picking up? Are the clouds getting darker to the west? What are the birds up to? Is the barometer rising or falling? Are there whitecaps on the chop a mile or two out? That powerboat near the horizon, how's it handling the waves?
Even if you do keep an eye on all of that, you will occasionally get caught out in a bit more than you bargained for- as we did a couple of weekends ago, when the wind came up far stronger and from a different direction than any of the forecasts had predicted. An important piece of the puzzle, therefore, is your knowlege of your boat's capabilities: Always plan your trips to keep a couple of Beaufort numbers worth of seaworthiness in reserve, just in case your plan doesn't quite work out.