Are you tempted to head out into the mountains on Thursday when high temperatures are expected to crack 70 degrees in some areas of the Puget Sound region for the first time this year? If so, be careful.

While the warmup will likely be greeted with enthusiasm by much of the region’s residents, it creates unusually risky avalanche conditions in the backcountry, said the Northwest Avalanche Center in a tweet.

“Uniquely dangerous avalanche conditions are expected Thursday as rapidly warming temperatures and strong sunshine cause the snow to become unstable,” the center said. “Large natural avalanches could occur. Some of these slides could be big enough to bury, injure, and kill a person.”

The danger is listed as “considerable” or “high” throughout the Cascade Mountains, according to the center.

Thursday’s relative warmth is due to a high-pressure ridge sitting over Northern California that brought 90-degree temperatures to the Sacramento Valley and is working its way up into Oregon and Washington, said Mike McFarland, a meteorologist with the National Weather Service in Seattle.

But it will be short-lived, he said.

A cold weather front from the North Pacific will come onshore Friday, cooling things down considerably — and quickly.


It will be rather chilly with highs in the mid- to upper-40s, lows in the mid-30s and a chance of some snowflakes in the foothills.

It’s even possible on Sunday that we could break the record low of 33 degrees at Seattle-Tacoma International Airport. That record was set in 1945, McFarland said.

“I wouldn’t be surprised to see a skiff of slush on the lawn,” McFarland said.