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)
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.
Unsettled weather for the extended Labor Day weekend will be across the Southeast, Upper Midwest, northern Rockies and the Four Corners.
Tropical Depression 14-E is several hundred miles southwest of Mexico and is expected to strengthen slowly into a tropical storm.
A stormy weather pattern will prevail through September across much of southern South America.
While lulls in tropical activity in the Atlantic will continue, a rapid end to the hurricane season in September does not always occur during an El Niño.
The combination of moisture from Erika and a non-tropical system will drench areas from Florida to the South Carolina coast through the middle of the week.
Heat will be erased by an autumnlike air mass across parts of northern Europe.
Mecca, CA (1950)
126 degrees - highest ever for U.S. in Sept.
East Coast (1775)
Matecumbe Key, FL (1935)
Labor Day Hurricane hit Florida. Pressure at Matecumbe Key dipped to 26.35"/892.3 mb. Most intense hurricane ever to hit the U.S. with 200-mph wind. Tide of 15 feet; 408 dead.