Winter is finally coming, with much-needed…

The first real taste of winter in Wyoming is expected later this week, and it comes a month late for the more than 1,500 firefighters working to extinguish two massive wildfires in Wyoming that are burning nearly 170,000 acres in the northern part of the State burned down.

It's a much-anticipated seasonal change after a warmer and drier-than-average fall that was marred by the wildfires. By the end of the week, the state will finally see some relief.

Colder temperatures, rain and snow are included in the extended forecast.

“It seems like a safe bet that the change will happen here by the end of the week,” Cowboy State Daily meteorologist Don Day said.

Fire extinguisher

While the seasonal change from summer to fall is always expected, there is a particular urgency this year due to the intensity of the Bighorn Mountains elk fire burned about 90,000 acres, while the Pack Trail Fire in the Bridger-Teton National Forest has burned nearly 78,000 acres.

Both fires remain volatile and dangerous, with containment of the Elk Fire at 27% and the Pack Trail Fire at 0%.

“I definitely believe there will be enough snow on the Elk Fire and the Pack Trail Fire to significantly support fire activity,” Day said. “Everyone wants numbers, but to talk about it so far out is just foolhardy. “But I'm very confident that it will snow in the mountains.”

Day wasn't sure whether the coming weather would be enough to put out any of the fires, but expected snowfall and a significant drop in temperature should help firefighters. And there's more to come after that.

I called it

For weeks, Day has been urging Wyomingites to wait until October 18 for winter to change. Judging by this week's extended forecast, he was right.

Historically, the third week of October is the limit at which Wyoming's unseasonably warm waterfalls end. Day noted that the upcoming winter weather system was consistent with the Cowboy State's historical precedent.

“History is on our side,” he said. “In the third week of October, daylight changes faster and the air gets colder. At some point you can't stop it anymore and autumn will come. Normally there will be no delay beyond the third week of October.”

The timing is almost perfect. The first snowflakes could fall across northern Wyoming on Thursday night, but the statewide shift begins on Friday (October 18).

Still, Wyoming is a big state. While every corner of the Cowboy State will feel and see the change, Day said it won't happen everywhere overnight.

“We have to split it up a little bit,” he said. “The event for the state will take place from Thursday to Saturday, but it will affect the northern and western areas first and the eastern and southern parts of the state last.”

When and where

The “event” will begin sometime between Thursday evening and Friday morning in the mountain passes of Wyoming. Day expects wintry weather conditions in all mountain passes in northern, central and southeastern Wyoming through Friday.

“Powder River Pass, Burgess Junction, Togwotee Pass, Teton Pass, South Pass and Beartooth Pass will have wintry driving conditions Thursday evening into Friday,” he said. “It will snow on all the mountains by Saturday.”

“Accumulation of snow” is the key phrase in Day’s assessment of the coming weather system. The snow that falls this week will form the basis of Wyoming's seasonal snowpack.

“Some showers will develop across the western border counties of Wyoming as early as Wednesday evening and Wednesday night,” he said. “We will see rain and snow break out across Yellowstone on Thursday and into Jackson, Star Valley and down to Evanston on Thursday evening. This should reach places like Sheridan and Buffalo.”

Once the system reaches northwestern Wyoming, it is expected to split and slowly drift eastward. Rain and possibly snow were forecast for eastern and southwestern Wyoming late Friday through Saturday.

“It will snow in the southern passes like the Snowy Range and Battle Mountain Pass by Saturday,” he said.

While snow is certain to fall in the mountains, Day expects the incoming system to be strong enough to drop snow in the low-lying areas of northern Wyoming. Whether it will stay is another question, and he doubts it will stay that way.

“I think there's a really good chance that people (at lower elevations) will see snow,” he said. “But if it's as warm as it has been and the ground is still warm, the first layer of snow will melt a bit . It is too difficult to talk about accumulations, at least today.”

Sudden anticipation

Day wants Wyomingites to know that this coming winter's weather system will represent an “abrupt change” for the entire state. He hopes everyone prepares accordingly.

“We should focus on the abruptness of change,” he said. “Many hunters hunt elk in the high country and have no weather at all to contend with. It will be a very different situation at the campfire on Thursday and Friday in many areas of the state.”

Anyone driving over mountain passes should be careful and expect dangerous winter weather conditions. Day believes it's still too far out to predict how much snow will fall in that four-day period, but it's likely to be significant.

Day isn't speculating beyond Saturday. The National Weather Service expects warmer temperatures to “bounce back” next week, but Day believes it's too early to tell.

“When there is a change like this, there will always be an upturn,” he said. “The question is how big the upswing will be and how long it will last. I certainly can’t imagine us going into the deep freeze and staying there for weeks, but we need to change the pattern first.”

Andrew Rossi available at [email protected].