Weather service swaps 'extreme wind' for 'extreme cold'
The National Weather Service is not abandoning wind chill. They will just be talking about it less.
"Wind chill with a different name," is what National Weather Service meteorologist Greg Gust called the agency's move toward issuing extreme weather warnings rather than wind chill warnings.
The weather service began using extreme cold warnings last January along with extreme wind chill warnings. This winter it will drop the extreme wind warning.
"Last year, extreme cold warnings started but we were also using extreme wind chill warnings," said Gust, the service's warning coordination meteorologist. "This year, the subtle difference is that we won't issue extreme wind chill warnings."
Meteorologists will continue to measure the weather the same -- wind, temperature, humidity -- but the language they use to talk about it will be different. The goal is to make the description of how the weather feels consistent throughout the year and across regions. The method is "apparent temperature," Gust said.
In North Dakota, the apparent temperature -- how it feels outside -- concentrates on how hard the wind is blowing. In Florida, the same thing is dictated by what the humidity is, he said.
"We're just trying to move to terminology that's more consistent with how we treat both heat and cold," Gust said.
Extreme cold should be something that needs no explanation to anyone living in Greater Grand Forks, but Gust said the warning is meant to emphasize that conditions could be more dangerous than what just the temperature might suggest.
"It's really the cooling rate," he said, and that includes factors such as moisture, sun or other factors that make people lose heat faster even when the wind is not blowing.
"Wind chill is part of it. Basically, it's a way to add wind chill warnings when the wind drops off to nothing."
Extreme cold warnings will be issued when the apparent temperature is below negative 30 over a multiple county area for more than an hour, Gust said. The weather service issued one for northwestern and north central Minnesota Jan. 20-21.
Wind chill will be part of how meteorologists talk about the weather, even without wind chill warnings. The new term will emphasize that dangerous cold does not necessarily depend on the wind.
Christopher Bjorke is a reporter at the Grand Forks Herald, which is owned by Forum Communications Co.