After a wonderfully warm Wyoming fall, a season-changing weather system is expected to move through the Cowboy State this week.
The National Weather Service Office in Riverton is calling for a significant winter storm starting Wednesday evening and continuing through Thursday night. Accumulation of up to 6 inches of snow is possible in the high-elevation areas of the state, especially the Wind River, Bighorn and Teton mountain ranges.
More importantly, this is the first winter storm of the season that will impact the travel and psychology of Wyomingites across the state.
The Psychological Effect
Cowboy State Daily meteorologist Don Day classified the system as “the season-changing storm.” If it hasn’t felt like fall before, it will now.
“We’re going to see some low-elevation snow,” he said. “It’s a psychological thing for a lot of folks. Because we’ve had fabulous weather for most of the fall, this will be a shock to the system. I would describe it as the first typical winter-like storm of the season.”
The storm has the potential to throw everything at Wyoming. Rain, snow, thunderstorms and strong winds are all possible, Day said. Some areas might be lucky enough to get a little bit of everything.
Day thinks the Wind River and Bighorn mountains will get the worst of it, but all of Wyoming’s major mountain ranges will be covered in snow.
“I could see upwards of a foot or a foot and a half of snow in those areas. It’s going to be a downright winter storm up in the higher elevations,” he said.
Day’s primary concern is how the storm will affect the roads and highways in central and southcentral Wyoming. This will be the first time this season the state's major southern thoroughfares will see snow.
“There’s going to be winter travel late (Wednesday night) through (Thursday) night,” he said. “That includes high elevations on Interstate 80. This will be impactful. We’re starting to talk about winter driving, and nobody’s had to do that for a while.”
Day also cautions anyone traveling through the Powder River Pass, Burgess Junction, South Pass, Togwotee Pass and the highest points of the Black Hills to anticipate winter travel conditions and prepare for slowdowns, slick roads and reduced visibility.
Some Wyoming communities will see an accumulation of snow. Day anticipates Casper, Douglas, Lusk and Rawlins have the best chance of accumulating snow on cold surfaces and grassy areas.
However, whatever falls is unlikely to stick. Thanks to the pleasantly warm weather the last few weeks, it’s still too warm for snow in the lower elevations to linger, regardless of how many inches fall.
“A lot of (the snow) is going to fall and melt,” he said. “It’s really hard to pin down snow accumulations. But those communities have the best chance of seeing several inches of snow.”
A Weaker Rebound
So, is there no coming back from this? Is winter here to stay once the season-changing storm begins?
Day thinks there are still several days of nice weather to anticipate, but “nice” doesn’t mean the 70-degree weekend many Wyomingites have enjoyed so far in October.
“We will rebound. We’re going to have a nice weekend,” he said. “But this deep in the season, the rebounds aren’t as intense. We’ll clear out and have a dry weekend, but highs on Friday will be in the 40s and the 50s this weekend. That’s actually closer to the season averages.”
Nevertheless, the impact of this two-day storm is clear. If anyone wanted to pinpoint the beginning of the end of fall, this storm is likely it.
“This storm is saying the pattern’s different now and going forward,” Day said. “We’ve had a beautiful fall, but this storm will be followed by other weather events, and each one gets a little colder. This is definitely a season-changer.”
The best way to stay informed on winter road conditions is the Wyoming Department of Transportation’s 511 app, available for free on iPhones and Androids, and the WYDOT website.