Last week's thaw was a mere tease for the Midwest and Northeast with the polar vortex set to make an encore performance this week.
The end of this weekend will coincide with the end of the mild stretch of weather across the Northeast that sent temperatures into the 60s northward to Washington, D.C., and Philadelphia and the 50s in New York City and Boston.
Highs on Monday will be 10 to 20 degrees colder throughout the Northeast and mid-Atlantic following the passage of a band of rain and nuisance snow on Sunday night.
Colder air has already erased the mild spell across the Midwest, and Sunday should prove to be one of the "warmest" days of this week.
Waves of even colder air will pour down from the depths of the Arctic to the northern Rockies, Midwest and Northeast as this week progresses and the polar vortex plunges southward.
Each cold blast will dip into the southern Plains and South, leading to a brief drop in temperatures. However, the core of the polar vortex will have a firm grip on the northern tier of the U.S.
