After weeks of “perfect fire weather” that has fueled two massive wildfires in the state, Cowboy State Daily meteorologist Don Day says a much-needed cold spell has finally arrived in Wyoming with the potential to blanket much of the state with snow.
Wyoming is a large state with varied terrain, so the impact of the winter weather pattern moving across the state Thursday and Friday won’t be the same everywhere. Day wants Wyomingites to have realistic expectations for the season's first storm, but it’s looking best where it’s needed most.
“The areas that need it the most are going to have the best chance of seeing the most significant precipitation,” he said. “The biggest impacts will be up high, and this is the snow that will stick.”
Down But Not Out
This week’s weather is good news for everyone in the vicinity of the Elk Fire, which has burned more about 96,000 acresand was only 28% contained as of Wednesday. The National Weather Service (NWS) anticipates up to 17 inches of snow could fall over the Bighorn Mountains between Thursday and Saturday.
Meanwhile, the Pack Trail Fire in the Bridger-Teton National Forest has burned over 88,000 acres. The NWS anticipates up to 14 inches of snow in the western region of the state over the next three days.
Day wouldn’t speculate on how much snow each region would receive, but was confident both fires would get a significant amount of precipitation. With the simultaneous drop in temperature, the snow should make a big dent in the infernos.
“Both fires are in the areas where the heaviest precipitation will fall,” he said. “It’s going to be all snow above 8,000 feet. This weather event will go a long way to give (firefighters) the upper hand.”
That said, Day was unsure if the snow would be enough to extinguish either fire. He recalled the aftermath of the devastating fires in Yellowstone National Park during the 1980s.
“Stumps were still smoldering the next spring, and underground root systems were still burning,” he said. “Every fire and hot spot is different, and I don't have the expertise to tell you whether or not it will extinguish anything. We’ll have to see where we are on Sunday and Monday.”
40 Degree Difference
Precipitation alone isn’t enough to bring about seasonal change. Fortunately, Day said the incoming weather pattern is also bringing an incredible drop in temperature.
“We’re talking about a 30- to 40-degree swing in temperature,” he said. “There were 80-degree temperatures Wednesday, and much of Wyoming won't be any warmer than the 40s on Friday. Some places in western Wyoming won’t even get out of the 30s. That’s as good as it’s going to get.”
Temperature-wise, this is still a “roller coaster” time of year. Day said a “rebound” is on the horizon, but it won’t be as warm and enduring as the first half of October.
“Temperatures will rebound next week, but it’ll only be in the 50s and lower 60s,” he said. “That’s about where they should be, close to average. Then there are a couple of cool fronts in the middle of next week and a stronger cold front next weekend.”
As far as Day is concerned, the warm days are done in Wyoming this year and for the next several months. So, enjoy what little warmth is left once it returns.
“You'll have three or four days of nice weather between these systems instead of 30 or 40 (degree) days, which we just went through in September and October,” he said.
The State Of Snow
The impacts of this week’s weather system will be evident everywhere in Wyoming. Day believes most Wyoming communities could see overnight snow in the next few days.
“I'm leery of giving numbers that would seem to apply to everybody,” he said. “We only have high confidence for the mountains, and lower elevation snow is likely, but I expect a lot of variability from location to location.”
In addition to the NWS maximum projections of 17 inches in the Bighorns and 14 inches in Bridger-Teton, Day believes the Wind River, Teton, and Absaroka ranges could see up to a foot of snow in the next three days. Casper Mountain and the Snowy Range could get between four and eight inches over the same period.
“Today, tonight, and tomorrow, those areas above 7,000 feet in the north and west will see snow,” he said. “It’ll start as rain today in Yellowstone National Park and the Bighorn Basin and snow overnight. Tomorrow morning, I see snow, especially in the southwest like Evanston, Green River, Rock Springs and Pinedale. Casper will see some snow, and Laramie has a chance for snow.”
That covers northwest, central, and southeastern Wyoming, which Day believes will see the most dramatic impacts from this week’s weather. Eastern and southwestern Wyoming won’t be left out, but Day said they won’t see as much precipitation this time.
“There's a gradient in terms of where the heavier moisture will be, west to east,” he said. “It’s going to get wet in those areas and further east out into the plains, but not nearly as much.”
The ground is still too warm for snow to stick in the lower elevations, but it’s only a matter of time. Until then, Day believes most of Wyoming will see snow sometime in the next few days.
“Will most of Wyoming get snow? Yes,” he said. “Will it be shovelable? No.”
The New Normal
A La Niña winter is brewing over the Pacific Ocean, which tends to dominate Wyoming’s weather patterns. The same phenomenon that made September and October feel more like summer is destined to bring a colder, snowier winter to much of Wyoming
“The La Niña influence was very strong here in September and October with the warmth and the dryness,” he said. “But a warm September and October don’t apply to the rest of the season. Other things are happening in the Pacific, which means it will get colder.”
While the full brunt of the winter season is still a few weeks off, Wyomingites should anticipate winter weather conditions when these smaller systems move through the western U.S. over the next several weeks. As far as Day is concerned, the dog days are over.
“From what we're seeing, there’s a pretty strong signal that these systems will be cold for snow onto the plains by the end of October and early November,” he said. “We've made it pretty deep in the fall without a strong system like this, but our luck would eventually run out regarding the nice weather. This is it.”
Andrew Rossi can be reached at arossi@cowboystatedaily.com.
