webspotting 20 - Weather Network

As published in the Apr/May 2011 issue of SCOPE, the newsletter of the RASC Toronto Centre. Republished here with permission.

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Astronomers are, by nature, amateur weather forecasters. We stare at the afternoon skies looking for high cloud, we watch the barometric trend, we check wind direction and monitor the dew point prediction. We dive into our trusted internet resources like the Clear Sky Chart  and  Environment Canada. Prevailing wind, day time heating, seasonal factors must all be considered. We tap the crystal of our old analog barometers. We stare at radar images, the visible clouds, the infrared, from satellites on high in the comfort of our homes. How will all these things affect our precious transparency and seeing?

I've always been a big fan of Environment Canada's weather resources. You may know that this is where, ultimately, the data from the Clear Sky Charts comes from. I'm guessing here but I suspect many other weather-reporting sites simply use or reference EC. So I've always gone to the horse's mouth.  It's one of the many tools in my tool kit.

Now we have a new weapon—nightly weather predictions—yes, condition predictions in the Long Term Forecast for evenings. This includes POP %, high temperature, low temp (with wind chill), wind direction and speed. The icons are most helpful to rapidly assess the upcoming nights.

These are provided by The Weather Network. The WN web site is not a new one. It's been around forever, well, since 1996 anyway, when the Internet was still very young. But recently the Weather Network added a little tab onto their future forecast element: the Night tab.

They don't document on their site how they arrive at these predictions exactly. But that's not entirely out of order: the weather services do not explain their magic tricks.

So, surf info http://www.theweathernetwork.com/, type your preferred location in the Search box, and hit GO. The Current Weather details are shown at the top of the web page. Scroll down to the Short Term Forecast. You'll see that these include nightly predictions (that's not new). Continue scrolling past the Top Stories. And there it is: the Long Term Forecast with the Day and Night tabs. Good luck predicting your clear dark skies.