National Weather Service plans to issue 'extreme cold warnings'
The National Weather Service may be issuing a new type of weather warning in the next weeks. The NWS offices of North and South Dakota and Minnesota will experiment with issuing "extreme cold warnings," according to John Paul Martin, warning coordination meteorologist for the National Weather Service in Bismarck.
The new warning supplements the wind chill advisory and wind chill warning the NWS has issued in the past.
"We do have times when there are dangerously cold temperatures but no wind," Martin said. "We're adding another product to have something out there in those situations."
The new extreme cold warning will be issued if the temperature is forecast to be 30 degrees below zero or colder with winds of less than 5 mph.
A wind chill advisory is issued if the wind chill is between 25 below and 39 below with winds of 5 mph or higher. A wind chill warning is issued if the wind chill is more than 40 degrees below zero and the winds are 5 mph or higher.
Any weather conditions must cover a large area and last several hours before a weather advisory or warning is issued.
"Typically these conditions occur a few times each winter," Martin said. "It recognizes that conditions are dangerously cold without the wind."
Martin also said the warning may get its first use in North Dakota in the next days.
"For the next two weeks, we're looking at colder-than-normal conditions for the area," he said. "We have true Arctic air rolling right in from above the Arctic Circle."
The best chance of temperatures reaching the "extreme cold warning" area is this weekend, Martin said.
"At this time, we're looking at nighttime lows in the 20 below zero range and daytime highs of below zero," he said. "It's the type of weather when your daytime high is colder than a normal nighttime low."
The normal temperature range this time of year is highs near 20 degrees with lows about zero.