It almost makes you forget about the freezing, icy air outside. (keepitsimplefoods.com)
The northern polar jet stream (it has a counterpart in the Southern Hemisphere) is driven partly by the temperature contrast between masses of icy air over the North Pole and warmer air near the equator. (insideclimatenews.org)
A large body of scientists suspect that when that differential narrows, the jet stream starts to curve like a whip being cracked, dipping further south and pulling icy air behind it. (seeker.com)