Insider Blog: Dangerously cold temperatures for parts of the U.S. this weekend

As of just before 5 PM (Pacific Time), many parts of the northern plains and intermountain west are already seeing sub-zero temperatures. Parts of Montana are more than 20 degrees below zero! The Dakotas are not far behind with temperatures more than 10 degrees below zero. Keep in mind that these temperatures are BEFORE we factor in any wind chill.

The potential for sub-zero temperatures will extend deep into the heartland heading into the weekend. Potentially record breaking cold temperatures will be present this weekend and early next week for much of these areas.

Partly why so much arctic air will move into the U.S. has to do with a broad area of high pressure over the Gulf of Alaska. Since air flows clockwise around high pressure, the pattern allows for an abundance of frigid air to move into the U.S. Most of this cold air will be trapped by the rocky mountains, so very cold temperatures are expected for areas east of the Rockies while temperatures will warm gradually for the west coast.