Anyone who lives with wind knows the truth in the saying, “It’s not the cold. It’s the windchill.” When Wyomingites wake up on Monday, they'll experience both.
The National Weather Service (NWS) anticipates dangerous windchills as low as minus 50 as the coldest air of the subzero surge smothers the Great Plains and Rocky Mountains. In Wyoming, forecasts call for windchills ranging from minus 15 to minus 45.
Anyone brave enough to confront the cold will want to bundle up, but even several layers of winter clothing won’t completely eliminate the dangers these severe windchills present.
“It’ll be just straight cold air with very light wind,” said meteorologist Chris Jones with the NWS Office in Riverton. “Even 5-7 mph winds can make a big difference. We’re going to struggle to get much above zero on Monday.”
Dang That’s Cold
Jones said a weak cold front of Arctic air is causing a deep dive into subzero windchills. He described it as “a reinforcing shot of cold air” that will impact Wyoming overnight Sunday and through Monday.
“With that front, we’ll see winds from 15-30 mph up near the Montana border,” he said. “Most areas will see 10-20 mph for a few hours. That's where we'll see some of our coldest windchills, and temperatures will drop further.”
With the temperature drop and increase in winds from the cold front, it won’t take much for the cold to become dangerous for people to be in for any length of time, and Jones said elevation will be a significant factor in determining which regions see the lowest lows.
“A lot of areas could see windchills that are minus 20 to minus 30, but the mountains will get colder,” he said. “We could see temperatures between minus 35 and (minus) 50 in the Bighorn Mountains between Sunday night and Monday evening.”
The circumstances will be reversed by Monday evening.
Jones said southeast Wyoming will experience the lowest windchills and strongest winds in Wyoming by then.
“We'll start to see the coldest temperatures shift down into the I-80 corridor, from Rawlins toward Laramie, by Monday evening,” he said. “Overnight temperatures along I-80 might range from minus 10 to minus 20. The fact that the wind could be picking up to 20-30 mph simultaneously means that's where those coldest windchills will be.”
Facts And Feelings
Windchills won’t be the only thing people will have to deal with. While the Arctic front is relatively dry, there will be enough moisture for light snow flurries to form.
“There'll be a brief shot of light, dry snow and very low accumulations across northern Wyoming and into the central basins,” Jones said. “We're talking a quarter, maybe a half an inch at best. A
“After that front clears we'll see some clearing skies from north to south, and the timing of when those clouds leave will greatly impact temperatures.”
Once the clouds clear, Monday should be mostly sunny, but daytime temperatures will still struggle to stay above zero, but don’t let that fool you. Without windchills, daytime highs across Wyoming range between 10 and minus 10.
With windchills, daytime temperatures could feel as low as minus 45 in some areas, while most areas will range from minus 15 to minus 30. That’ll feel pretty dang cold.
Nevertheless, feeling cold isn’t the same as actually being cold.
Jones said it’s unlikely that any Wyoming communities will reach record lows.
“The NWS doesn’t keep wind chillrecords,” he said. “As far as straight air temperatures, we could get close at places like Casper. But with the wind picking up and the clouds clearing, it won't go as cold, so we probably won't set air temperature records.”
Even if it technically isn’t that cold, it will feel colder. This means anyone planning to go out in the cold must keep themselves covered.
30 Minutes Or Less
Anyone stepping outside Monday morning will feel the cold immediately, but it won’t take much longer for it to become dangerous. Jones said it only takes a few minutes to go from frigid to frostbite.
“When it’s between minus 10 and 20 degrees, you can get frostbite in 30 minutes or less,” he said. “When you reach minus 30-35, you’re talking about 10 minutes or less. But if you aren’t properly prepared, it won't take temperatures even close to that to cause problems.
The NWS now issues Extreme Cold Warnings in lieu of focusing on windchills. Most of Eastern Wyoming is under an Extreme Cold Warning until 11 a.m. Monday, while the rest of the state is under a Cold Weather Advisory until 8 a.m. Tuesday.
Since most of Wyoming will experience windchills colder than minus 10, exposed skin could be quickly and seriously damaged. Jones cautioned everyone to dress appropriately and limit outdoor exposure as much as possible.
“Even if you’re geared up for cold weather, you’re still in a situation where any exposed skin could get frostbitten in 10 minutes,” he said.
What We’re In For
Here’s the National Weather Service forecast for daytime highs and possible windchills across Wyoming for Monday:
• Afton: High near 5, windchills as low as minus 15
• Buffalo: High near 0, windchills as low as minus 30
• Casper: High near 1, windchills as low as minus 16
• Cheyenne: High near 2, windchills as low as minus 30
• Cody: High near 4, windchills as low as minus 25
• Gillette: High near minus 3, windchills as low as minus 36
• Jackson: High near 5, windchills as low as minus 35
• Lander: High near minus 1, windchills as low as minus 25
• Laramie: High near minus 2, windchills as low as minus 35
• Lusk: High near minus 5, windchills as low as minus 45
• Pinedale: High near minus 2, windchills as low as minus 40
• Riverton: High near minus 1, windchills as low as minus 30
• Rock Springs: High near 4, windchills as low as minus 25
• Saratoga: High near minus 1, windchills as low as minus 30
• Sheridan: High near 6, windchills as low as minus 35
• Thermopolis: High near 4, windchills as low as minus 25
• Wamsutter: High near minus 3, windchills as low as minus 35
