As advertised, the cold air is coming

The weather pattern change that we started talking about early last week is unfolding Monday across the northern part of the United States.

A very strong storm system that battered western Alaska last Friday helped create a kink in the jet stream, and that is allowing an outbreak of arctic air to blast into much of the United States.

The cold air will reach the Charlotte region Thursday, but the heart of the arctic outbreak appears to be aimed at the central third of the United States. Places like Des Moines, Iowa, are not forecast to climb above freezing for much of the week. In Dallas, where the front is expected to arrive Tuesday, post-frontal high temperatures will only reach the 40s.

The cold air will trigger an outbreak of heavy lake-effect snow squalls in the Great Lakes.

And forecasters said long-range guidance from the computer models points to a second surge of cold air about a week from now. The coldest of that air might be aimed farther eastward, toward the eastern Great Lakes, the Northeast, and the Southeast.

This change in the pattern will last a while -- probably two weeks and maybe a bit more. That will take us into the beginning of Thanksgiving week.

So far, there are no strong indications that storm systems will form in the Southeast while the heart of the cold is around. And that will prevent an early-season snow or ice event, although there is a chance that a low pressure system expected to form in the Gulf of Mexico on Friday could bring snow to the North Carolina mountains Sunday.

We said good-bye to the 80s with the arrival of a strong cold front a few days before Halloween. Now it looks as if the next outbreak of very chilly air will mark an end to the 70s, at least for a while.