I rarely agree with Farhad Manjoo, who covers matters of technology for Slate. But he's right that Weather Underground is the place to go for the best forecasts on the web. I actually pay attention to this stuff and W.U. is where I go. Like most of these sites, much of what they offer is the same National Weather Service data that's available to all. But if for no other reason that to have something unique to sell, most weather sites supplement the N.W.S. forecasts with their own computer models. For reasons Manjoo explains, Weather Underground does it better…and it's free unless you want to subscribe and see more radar info and a page that's free of advertising. That will run you a measly ten bucks a year.
My informal studies find that Accu-Weather is the worst, in part because they try to gain a competitive advantage by offering a 15-day forecast. Almost every other company is pushing their luck to go past ten. Projecting Days 11-15 during times of volatile weather is impossible…and even Accu-Weather is constantly revising whatever they say. My birthday is nine days from now. Two days ago, Accu-Weather said it would be raining in L.A. that day. Yesterday, they said it would be cloudy. When I looked earlier this morning, it said it would be sunny. So their long-range forecasts are essentially worthless.
Accu-Weather is the Pennsylania-based private weather company that was at the forefront of a move in 2005 to stop the National Weather Service from giving us the forecasts that are generated by our tax dollars. A bill introduced into Congress (but which went nowhere) would have prohibited this. It would not have stopped the N.W.S. from doing its business and we would still have been paying for it…but instead of just telling us if it was likely to rain, the N.W.S. would only have been able to release their findings to private weather companies which would have sold that information to us. This would be like if we put up toll booths on every major street and thoroughfare in the country and while we still paid to build them, we let Hallburton set up the booths and keep the money.
The Senator who introduced that bill — and who coincidentally took a helluva lot of "campaign contributions" from Accu-Weather — was Rick Santorum.