After weeks of wondering when winter would arrive in the region, skiers and riders got their first tracks on natural snow Friday.

“When it gets down to it this time of year - we’re all watching the weather to see when we can go skiing,” said Bill Ortner, a Pennsylvania skier for 45 years and a board member of the Ptarmigan Ski Club based in the Lehigh Valley.

Pennsylvania ski areas only need a few weeks of freezing temperatures to establish a base that can be maintained through March. But December was one of the warmest on record.

One possible explanation is that this is a La Nina winter, generally thought to mean that weather in the Northeast will tend to be warmer, with less precipitation.

Ben Gelber, a meteorologist who has been tracking weather in Monroe County for decades, said La Nina and its counterpart El Nino give good estimates of how winter will play out, but other factors can produce a storm.

Conditions in December were typical of a La Nina. It was the second warmest December on record at Lehigh Valley Airport, where they’ve been keeping track for 100 years. On an average day, the high temperature was 47 and the low was 31.

Snow-making makes consistent skiing possible in parts of Pennsylvania that may see less than a foot of snow in some years. But it requires freezing temperatures, and the air can’t be too humid.

Blue Mountain Resort had some of its lifts turning on Dec. 3. While only some of the mountain was open, they had opened more terrain than any other ski area in Pennsylvania, according to Ashley Seier, director of marketing for Blue Mountain Resort.

This week’s change in the weather has brought freezing temperatures every night of the week. Blue Mountain has taken the opportunity to ramp up snow-making across their facility.

“The cooler temperatures this week have been a game changer for our snow-making team. We have expanded to 18 trails with slope access from both our Summit and Valley Lodges,” Seier said.

Seier said that unseasonable warmth and limited terrain have kept some skiers away in the early weeks of the season, but overall, demand for ski tickets is up.

“COVID helped a lot of people discover the sport or get back into it after a lapse. We are completely sold out of All Access Season Passes for this season, the demand to be outdoors is still very strong,” she said.

Lucky for those passholders, Gelber says La Nina years are still capable of producing winter weather.

2021 was a La Nina, and it was one of the snowiest winters in the area’s history.

On Jan. 31 to Feb. 1, a storm dropped 1 to 2 feet of snow on the area. The snow total for the month was over 50 inches.

The result was epic conditions for Pennsylvania skiers. Many, like Ortner, were forced to cancel trips to ski destinations in the Rockies and beyond. But they got the rare chance to ski in powder in Pennsylvania.

“There’s nothing like having natural snow to ski on,” Ortner said.

The rest of the winter, snow was scarce. During the months of January and March, Lehigh Valley Airport recorded virtually no measurable snowfalls. In December, there was one - 12.5 inches.

Gelber said, during a La Nina winter, there is usually a brief period where weather patterns shift, making conditions feel more like a normal winter.

Last year’s happened to coincide with a dipping of the polar vortex, which brought bitter cold as far south as Texas, and produced the major storm.

Gelber said he’s fairly confident that this year, January presents the best opportunity for winter conditions.

“For those looking for snow and watching their heating bills, they need to consider January won’t be anything like December,” Gelber said.

Blue Mountain plans to use the dip in temperatures to build its base. If current weather patterns hold, they hope to have 30 out of 40 trails open for the Jan. 15 to 17 Martin Luther King Jr. Day weekend.

Longtime skiers like Ortner know that there’s a lot of time left in the season.

“If they get that week or two when they get cold temperatures, they can put a lot of snow down. And once it’s down, it tends to preserve itself,” Ortner said.