(ACCUWEATHER) — A wave of arctic air will spread from the Pacific coast to the Atlantic coast of the United States during the first week of 2017.
The cold air will continue to invade the northwestern U.S. early this week. The cold air was accompanied by accumulating snow to near sea level in Washington on New Year's Day.
Over the Southwest, including Southern California and southern Arizona, the chilliest days will be the first part of the week as temperatures will moderate late in the week. Cold air will hang on much of the week in the Northwest.
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