The National Weather Service has issued a wind advisory for San Diego County’s mountain areas and deserts as a system of low ...

As of Tuesday morning, extreme cold warnings had been issued ... as well as almost all of South Dakota, Nebraska, and Iowa. In northeast Montana, wind chills as low as 58 below were expected.

The wind chill will reach as low as 7 below zero with winds gusting up to 10 miles per hour. The National Weather Service defines a winter weather advisory as, "winter weather expected.