Does this look like boating weather?

Today might be a good day to head out on the lake, if it's not too rough out there. Does this look like boating weather to you?

Wind maps from ECMWF, GFS, NAM and RUC models for Kingston, ON 25 Aug 2012

Here's what I see:

  • The four different forecast models DON'T agree on where the strongest wind is going to be, or how strong it'll be, in the morning out on the lake.
  • All four models DO agree that the wind will be at its maximum in mid-morning, and will start to die off in early afternoon. By 14:00 we should be down to about 6 knots in the region of interest. This suggests that the afternoon trip back north to Kingston should, if anything, be calmer than the trip away from Kingston in the morning.
  • All four models DO agree that for the entire day, the winds will be from SSE to SSW. This implies that waves will be mostly from the south, so we'll be running against them on the way out and with them on the way back. This is desirable, as it means the trip back should be easier than the trip out.

There are other features that often appear in these maps (but are absent today) that I would worry about:

  • Different forecast models disagreeing on the wind direction, rather than just the wind strength. This implies a possibly chaotic weather system and an increased chance of all the models being wrong.
  • Strong gradients in wind speed. It's rare for the wind strength to change dramatically over a short distance; if the forecast shows this, I'll take it with a grain of salt.
  • Winds from the north or west. In these winds, the trip out is easy but the trip back to Kingston involves beating into a head wind or running with the waves on the beam- and open water to windward all the way to Rochester. Apparently light winds can kick up pretty substantial chop in this part of Lake Ontario, given enough fetch.
  • Powerful systems of any kind within 500 km to the west or south-west, on the models, radar or satellite images. Whatever Sarnia and Kincardine are getting now is, if it's strong enough, likely to hit us by the end of the day.

Do we chance it today? I'm going to say yes.... it's time to grab some food and hitch up Sunset Chaser's trailer. As always, though, we'll be checking WX2 on the VHF periodically and we'll be prepared to sprint for home if things don't turn out as expected.

(Screenshots are from the wonderfully slick WunderMap tool by Weather Underground.)





The actual result

Matthew's picture

Not surprisingly, it turned out to be a beautiful day.

The winds out on the lake were about four knots stronger than forecasted by the first three models- the RUC model turned out to be the closest to reality, but it too was an underestimate. In 8 knots, it's easy to go clear across the lake; in 12 knots, there's just enough of a sharp crest on the waves to keep small open boats like ours away from the open water.

Our solution to this conundrum is to have a few possible destinations, and wait until we're out there to make the final call. If it's too choppy to cross to Wolfe Island in comfort, there are half a dozen closer, calmer anchorages that are also quite nice.

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