By Saturday morning, many thermometers in the eastern United States will be registering their lowest marks of the winter or may come within a couple of degrees.

A burst of painful cold will follow the storm that is unleashing rain along much of the Eastern Seaboard and more snow to the north.

Even though Arctic air of this magnitude forecast for the eastern United States is common during the middle of February, the upcoming frigid conditions could be a shock for millions in the middle of what's been a mild season so far.

Meanwhile, the northern Plains and Upper Midwest face downright dangerous conditions with this bitter blast.

It's been a warm winter for much of the East with temperature departures ranging from 4 to 8 degrees above average.

But temperatures are expected take a nose dive and drop by as much as 30 to 50 degrees from the daytime Thursday to Friday night.

Friday's highs could be 15-25 degrees lower than Thursday's.

Temperatures ranging from the 30s across the northern New England to the 80s in the South on Thursday will be swapped with Saturday morning temperatures below zero in the northern tier to the 20s and 30s in much of the South.

By Saturday morning, many thermometers in the region will be registering their lowest marks of the winter or may come within a couple of degrees of the season's benchmark set way back in mid-December, during an earlier outbreak of Arctic air.

TEMPERATURES FOR DELAWARE TURN WARMER SUNDAY

The good news is the cold snap won't last long.

Here's the forecast for temperatures in Dover, Delaware:

Friday, Feb. 14, high 34, low 15

Saturday, Feb. 15, high 35, low 25

Sunday, Feb. 16, high 50, low 31

Monday, Feb. 17, high 50, low 36.