Do you need a 10 liter or 30 liter? Will a frameless pack be comfortable enough or do you want to pay full freight for true load lifters? Does your backpack need to be waterproof? I took a look at ...

According to the NWS, the Arctic polar vortex is a powerful band of west-to-east winds that develops in the stratosphere, about 10 to 30 miles above the North Pole, during the winter season.

However, a deep freeze, thanks to the polar vortex dipping down from Siberia, is bringing an even harsher arctic blast to million Americans this week. Maps show what to expect as the cold front ...

A dangerous and potentially life-threatening stretch of cold weather has much of the U.S. on alert as a lobe of the polar vortex invades the nation and sends temperatures tumbling to levels not seen ...

The coldest weather of the season to date will be due to a phenomenon called a polar vortex ... D.C., with wind chill set to make it feel even cooler. States from Virginia up into New England ...