Today

# The Friday Fillip: Rain

“For the rain it raineth every day”

I like rain.

I’ve figured out that it allows me to escape the parental injunction to go outside and play when all I really want to do is curl up in a chair with my nose in a book. Funny how these things stick around from childhood. But they do, and for me a rainy day drops the curtain on the infinite horizon and snugs things up cosily, whether I’m out in the wet complaining about it or inside and dry.

We get plenty of rain here in Canada — though it’s not evenly distributed. And it’s difficult to tell exactly how much rainfall we get because the weather stats sites I could find lump all precipitation together. Whatever else you may say about snow, you have to admit that it ain’t rain. But as you might imagine the west and east coasts get most of the wet, with Vancouver and Halifax scoring highest among the major cities, and the far north — Whitehorse and Yellowknife — getting the least precipitation. But for the truly soggy Canadian experience you’d want to go to Moresby Island in Haida Gwaii which suffers an astonishing 6325 mm — that’s 20.8 feet — three and a half fathoms! — of preciptation a year, 99% of which falls as rain.

Whether it’s a downpour or a mizzle we’re talking about, most folks want to avoid getting wet. There are two principal ways of doing that: one is to anticipate the rain and take precautions; and the other is to fend it off.

When it comes to prediction, it’s the PoP data that counts. The “probability of precipitation” is given in percentages (in tens), but apparently has people confused as to what it means exactly (all part of our human difficulty with mathematical probabilities). According to the U.S. National Weather Service:

PoP = C x A where “C” = the confidence that precipitation will occur somewhere in the forecast area, and where “A” = the percent of the area that will receive measureable precipitation, if it occurs at all. [emphasis in the original]

So because there are two factors, a particular PoP can mean either of two different things. For example, if the forecasters say there’s a 40% PoP, it might mean either that they are 100% confident that it will rain in 40% of the target area, or that they are 50% confident (based on similar patterns in the past) that if it does rain it will do so in 80% of the target area. This seems to me to make it pretty much useless as a predictive device — are you in the affected area? how would you know? — so, against the advice of weather people everywhere, I take PoP to be simply a measure of the likelihood of rain — betting odds, if you will, that it will rain. In my simplistic version, then, 40% PoP means the odds are 2 to 5 that it will rain.

More reliable, perhaps, are tools to protect oneself from the rain. I offer you two, here, both picked by the stellar Wirecutter as the best in their category.* The best inexpensive rain jacket is the Marmot PreCip, a superb waterproof and breathable shell. And the best umbrella is the EuroSCHIRM Light Trek, an optimal combination of price, sturdiness, size when expanded, and smallness when collapsed.

If, however, you should find yourself in a cloudburst SCHIRM-less and sans PreCip, what’s the recommended action? Will you get less wet if you walk or if you run to shelter? The answer — proven by science (of sorts) — turns out to be walking:

That shelter I ran strolled to? Here in Toronto it might well be one of the “top 10 patios for a rainy day.” Few things are better than sipping a beverage while contemplating the rain from under a roof. I did try to find the equivalent information about other cities in Canada, but wasn’t able to come up with anything useful. So if you happen to have such useful information about your town, don’t hesitate to share it via the comments.

“…the small raine down can raine…”

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* Let it never be said that your Friday Fillip is not au courant (though you may say it uses double negatives freely): even as I write this (a week before publication) The Wirecutter has published an entry confirming their choices of jacket and umbrella because they’ve just been tested in a monsoon and found effective.