WASHINGTON — Cold and snow keep battering the Midwest and East, and even Atlanta was temporarily paralyzed. California has been bone dry. Alaska set heat records.
The wild winter somehow became even more wicked Thursday morning when the national average temperature plunged to a brutal 11 degrees — the lowest temperature in a season of extremes.
A weather-weary nation asks a simple question: Why?
The answer is the jet stream, the river of air that dictates our weather. Normally the jet stream stays in Canada or the northern United States, going west to east in a somewhat straight line. But this winter it has plunged south, creating high pressure ridges and low pressure troughs while taking cold polar air south and east, leaving warm, dry weather to the west.
"We are having an unusual jet stream that's giving us crazy cold weather in the East and the ridiculously resilient ridge as it's called in California," said Weather Underground meteorology director Jeff Masters.
When will it end?
Soon enough. In Northern California, heavy rains are coming. And a predicted eastern winter snowstorm this weekend is looking less mighty than it did a few days ago.
It won't be too soon for the meteorologists who predict it.
"I'm sick of it," said Bruce Terry, of the National Weather Service's Weather Prediction Center in College Park, Md.