TRUCKEE (CBS13) — The coldest and biggest snowfall of the season has begun in the Sierra. And now a winter storm warning is in effect for most of the towns in the upper elevations.

“It can be dangerous during certain storm cycles,” said Joe Flannery, a spokesperson for Tahoe National Forest.

It was covered in Christmas lights Wednesday night but in just 24 hours, Historic Downtown Truckee will be covered in snow.

“Oh it couldn’t be any better timing,” said Wils Riley, who visited Boreal Ski Resort on Wednesday. “It’s going to be awesome. We both got season passes so we’re going to shred it up this year!”

But Wednesday night, skiers and snowboarders in the Sierra only got a taste of what’s to come.

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“Right when we got to Boreal, it started snowing, which is like perfect for us,” said Keaton Vogel, who drove up from San Jose.

Flannery told CBS13 the winter storm comes with a warning.

“If you’re driving up here, driving to high elevation to the mountains, just be prepared,” he said.

That means stocking your car with food, blankets, and chains that may be required at certain points. On Thursday, the first avalanche advisory of the season will be released.

“It’s essentially a forecast of avalanche risk, potential avalanche problems and a mountain weather forecast,” Flannery said.

Forest officials are taking safety precautions, yet many visitors fail to do the same.

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“They find a way to get up here, but they might not always find a way to get home,” said Scott Perkins, General Manager at Tahoe Sports Hub.

He said the last few weekends have prepared him for the rush he’s likely to get this weekend.

“We got all the new gear in, people are super excited, we’re all staffed up,” he said.

And businesses such as La Galleria are banking on winter weather bringing more customers through their door.

“They ski one day and they shop one day so that’s always a bonus!” said Brooke Bentley at La Galleria on Donner Pass Road.

And that already sounds like a safe bet.

“We’ll be back tomorrow or the next day!” said snowboarder Beverly Flood.

If you’re driving up as the weather hits, be prepared to stop for chain control and stock up. And remember: Buy what you need before you need it.