WeatherFanatics: By the Numbers: RealFeel Temperatures Plummet to Brutal Extremes in US

By Meghan Evans, Meteorologist

January 7,2014; 6:12PM,EST

Long-standing records were shattered across the East and South on Tuesday morning, as the coldest air in 20 years arrived.
An unusual positioning of the polar vortex is the culprit behind the dangerous cold. The polar vortex is a large pocket of very cold air, which sits over the polar region during the winter season, and it has shifted unusually far south into the U.S.
AccuWeather RealFeel® temperatures have been even lower than actual temperatures due to icy winds and seven additional parameters taken into account by this unique index. It is one of a kind because AccuWeather is the only company that can use more than two elements in its equation, because it is patented. Additional factors, such as humidity and sun angle, can make a big difference in how cold it feels outside.

Commuters exit Union Station with AccuWeather RealFeels® below 30 degrees below zero F on Tuesday, Jan. 7, 2014, in downtown Chicago. (AP Photo/Andrew A. Nelles)
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The cold was extreme enough to close schools, threaten frozen pipes and cause significant flight delays.
Atlanta Public Schools were closed for the safety of students and employees on Tuesday as the temperature plunged into the single digits in the morning. An emergency shelter was opened by the City of Atlanta to provide warmth and cots for residents as the unusual cold arrived.
Numerous record lows fell as the cold gripped the region on Tuesday, and some were records set more than 100 years ago.
"Philly and Atlanta recorded their first January record lows in the 21st century on Tuesday morning," AccuWeather Senior Meteorologist Alex Sosnowski said.

Highlights of Record Lows Shattered on Tuesday Morning

4 F in New York City's Central Park

The old record for the date was 6 F which was set back in 1896. The AccuWeather RealFeel® temperature fell below 20 below zero F Tuesday morning.

4 F in Philadelphia

The old record for the date was 7 F which was set in 1988. The AccuWeather RealFeel® temperature reached as low as 25 below zero F Tuesday morning.

13 below zero F in Dubois, Pa.

The old record for the date was 5 below zero F which was set in 1988. The AccuWeather RealFeel® temperature plunged to 45 below zero F Tuesday morning.

8 below zero F in Zanesville, Ohio

The old record for the date was 3 below zero F which was set in 1968. The AccuWeather RealFeel® temperature hit as low as 36 below zero F Tuesday morning.

6 F in Dover, Del.

The old record for the date was 10 F which was set in 1988. The AccuWeather RealFeel® temperature dropped to 24 below zero F Tuesday morning.

3 F in Baltimore

The old record for the date was 8 F which was set in 1988. The AccuWeather RealFeel® temperature was as low as 20 below zero F Tuesday morning.

10 F in Richmond, Va.

The old record for the date was 12 F which was set in 1988. The AccuWeather RealFeel® temperature reached 12 below zero F Tuesday morning.

9 F in Raleigh, N.C.

The old record for the date was 15 F which was set in 1988. The AccuWeather RealFeel® temperature was as low as 10 below zero F Tuesday morning.

7 below zero F in Morgantown, W.Va.

The old record for the date was 4 below zero F which was set in 1970. The AccuWeather RealFeel® temperature dropped below 25 below zero F.

7 F in Charlotte, N.C.

The old record for the date was 12 F which was set back in 1884. The AccuWeather RealFeel® temperature was as low as 2 below zero F early Tuesday morning.

13 F in Columbia, S.C.

The old record for the date was 16 F which was set back in 1924. The AccuWeather RealFeel® temperature plummeted to 5 F Tuesday morning.

6 F in Atlanta

The old record for the date was 10 F which was set back in 1970. The AccuWeather RealFeel® temperature bottomed out at 11 below zero F Tuesday morning.