People living "basically anywhere from the Rockies eastward" will see extremely cold temperatures over the next several days, a meteorologist says.

Portland was forecasted to be about 6 degrees below normal Sunday and Monday, according to the National Weather Service.

However, a deep freeze, thanks to the polar vortex dipping down from Siberia, is about to bring even harsher arctic blast to nearly 300 million Americans starting this weekend. Maps show where and when the cold front will arrive.