The National Weather Service is scrapping the use of "extreme cold" watches and warnings in the Upper Midwest in favor of the more familiar wind chill advisories and warnings.
The weather service experimented with the "extreme cold" advisories in North Dakota, South Dakota and Minnesota to emphasize that dangerous cold does not necessarily depend on wind. Wind chill is the measure of how cold it feels once the wind is factored in with the air temperature.
Meteorologist John Paul Martin says last year's mild winter didn't make for a good trial year.
He also says there was confusion in some markets such as Minneapolis, where the weather service also serves areas of Wisconsin, which was not part of the trial.