Large, cotton ball-like snow flakes hit the ground in Jackson on Monday morning for the first time this fall.

Then, after a bit of accumulation, the precipitation turned to sleety drizzle and, later, to a cold rain.

The premiere snowstorm of the season arrived with the front edge of a system coming off the Pacific Ocean and crossing the Northwest. A chance of snow is forecast throughout the week. The National Weather Service predicts the storm could drop 4-10 inches across the area.

Monday’s snow on the valley floor wasn’t enough to stick for long, but it was enough to remind people what’s coming.

Scott Shervin, owner of Shervin’s Independent Oil, said he has a full schedule for the next couple of days.

“Whenever it starts snowing, everybody goes crazy,” he said. “They want their snow tires on now.”

Higher up on Monday, Jackson Hole Mountain Resort reported an inch of snow in 24 hours, and 2 inches on the season. Grand Targhee Resort reported the same.

The Bridger-Teton Avalanche Center reported 4 inches at 3 p.m. Monday at its monitoring station at the top of Rendezvous Bowl. The Avalanche Center has been monitoring snowfall since the beginning of October on its website, JHAvalanche.org.

The first snowfall in the valley came a week after a rainstorm delivered the first snow to mountaintops surrounding the Hole.

Bob Comey, the director of the Bridger-Teton Avalanche Center, said the Oct. 18 rainstorm that dusted the Tetons left a potentially dangerous avalanche layer at elevations above 10,500 feet.

“I was up on the top of Rendezvous Bowl last week,” he said, “and the snow up there is like a sheet of ice. I was worried about slipping down the bowl just walking across the top.”

He said most of the frozen snow was at higher elevations than Jackson Hole Mountain Resort, which is good news for the ski area.

The Avalanche Center’s weekly summary described the layer as a “hard rain crust” and continued to advise that it “has the potential to become a bed surface for avalanche activity in the highest peaks of the Teton Range later in the season.”

The change in the weather is good for hunters, said Mark Gocke of the Jackson office of Wyoming Game and Fish.

With a “spotty harvest” so far, Gocke said, “the weather is welcome from a hunter’s perspective.”

Gocke said abnormally dry conditions have shifted where animals feed and water, and made it more difficult for hunters to move quietly through the woods.

He warned that the snow can make getting stuck on remote roads more likely. He also said roads are more easily damaged when they are wet.

Dan Berc, a meteorologist with the National Weather Service in Riverton, said the moisture ends an exceptionally dry summer.

“Jackson has not been hit as bad as the rest of the state,” he said, “but it’s been extremely dry, one of the driest on record.”

Moose has the only official precipitation data in the area. On average, Moose receives 21.43 inches of precipitation a year, and 16.72 inches on average between January and October. So far this year there have only been 11.63 inches of precipitation.

June, August and September were abnormally dry months, Berc said, but with Monday’s storm, October looks to be about average.