People love to hate weather forecasts, though it's getting a lot harder to find fault. Forecasts gave plenty of advance warning that Chicago would see a bitter high of around minus 24.5 on Wednesday, and lows Wednesday night comparable to a bad day in Antarctica. Public officials closed schools and issued warnings, and police saved lives by combing the streets for homeless people before the worst hit.

Today, a five-day forecast is just as accurate as a one-day forecast was in 1980, giving us more time to prepare — or overreact and panic.

Weather watchers in the Northeast United States saw this cold snap coming for days. Storms are now forecast within a range of around 80 km and timed to within a couple of hours. An icy storm that hit the Northeast on Jan. 20 was in the forecast before it even existed anywhere, said Richard Alley, a geosciences professor at Penn State University and co-author of a new paper in Science magazine on weather prediction.