It’s the 13th! Know what that means? It means that, at least until I change the logic again, that it’s the day you’ll see a photograph of a rainbow in Finland (it was an epic rainbow, believe me) in the header of the site. I know most of you don’t actually visit the site itself, but you can trust me.

So in that vein, I’m going to talk about the weather.

My OS X weather widget shows a mostly sunny icon for today. Word on the street is that it’s supposed to be mild. But here it is 10:38 and the sky is crusted over and it’s only 40 degrees. This got me to thinking about weather, forecasting, and challenge that putting the two together causes for meteorologists in the Pacific Northwest. I gather the weather is hard to predict here.

If you prefer to receive your weather outlook as more of a fascinating, introspective musing (often with shades of grey) than a simple icon, and you live ’round here, I highly recommend Fox 12′s Weather Blog. I like how the jargon and the zeal show through in passages like this:

Models continue to show longwave ridging over the Northwest through at least the early part of the next week. This weekend looks especially nice with very high 500mb. heights and a sharp ridge.

I also like how the forecast is posited as a theory, not an inevitability. The blogging weathermen question themselves and their data in their posts. There’s lots of use of “maybe.” I like that. And there’s a heck of a lot of commenting by other people who also seem to have zeal.

Also interesting to me is ForecastAdvisor, which has apparently been around for some time. They collect forecasts from the major providers and analyze it for accuracy. Looks like forecasts for Portland are right about 3/4 of the time, which is more than I would have expected. And their icon for today shows rain (albeit I can’t figure out the source of their forecast from their FAQ–is it boiled down from all of the forecasts they process or their own data?)! Also noteworthy is that you can click on a day’s forecast and see past guesses for the same day leading up to the current outlook.

Other interesting weather sites or data I should know about?

Thanks to @donpdonp for the inspiration here.