The remnants of a Pacific typhoon will pound Alaska with enough force to produce 50-foot waves, then shove across two-thirds of the Lower 48 and drive temperatures to wintry levels next week.
"It's early in the season, but we are poised for a pure arctic outbreak," said Tom Niziol, a winter weather specialist for The Weather Channel.
Forecasters said that the storm, as it approaches the Aleutian Islands this weekend, could be more intense than Superstorm Sandy when it swamped the Northeast two years ago.
The Coast Guard and Alaska emergency management authorities were watching the storm. It was expected to mix with cold air and the jet stream, producing hurricane-force wind and extreme waves, when it strikes late Friday or Saturday.
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Then comes early winter for tens of millions of people in the rest of the country. On Monday, the high temperature for Great Falls, Montana, is expected to be 25 degrees, or 20 degrees lower than normal for this time of year.
The high on Tuesday in Bismarck, North Dakota, is only expected to be 25, or 16 below normal. And on Wednesday, the mercury will only push to 51 in Dallas and barely above freezing in Cleveland.
By late next week, temperatures will be well below average as far south as the Gulf Coast. The system is also expected to bring snow to parts of the Rockies and Plains next week.