Arctic Air Hitting Below the Sun Belt

Patzert said that a blast of Arctic air was cascading like a huge U-shape across the Canadian border from Seattle to San Diego and much of the country, bringing stinging cold with it.

"We've had jet streams on steroids coming out of the Gulf of Alaska, but this is much colder air. This is a massive mountain of zero to sub-zero cold air," he said. "This is a huge mass of air, not just a jet stream. This is the big breakout that really is the signal for the beginning of winter."

State officials, who last summer struggled to deal with the deaths of more than 100 mostly elderly people during a record-setting heat wave, said Thursday they were gearing up to deal with this round of extreme weather.