SEATTLE — The warmest weather in more than six months has people out and about enjoying the beautiful Pacific Northwest but the rising temperatures and higher sun angle elevate the potential avalanche danger as well.
Because of the increased avalanche concern through the weekend, the Northwest Avalanche Center issued a Special Avalanche Bulletin through 6 p.m. on Saturday for the Cascades and Olympics in western Washington.
Across the region through the weekend the mild temperatures will extend into the higher elevations of the mountains. In fact, it's so warm that the freezing level will jump between 12,000 to 14,000 feet over the next couple of days with overnight temperatures staying above freezing for much of the area below that level.
Anyone using the backcountry - even if it's close to resorts - should exercise extreme caution or avoid it altogether.
"So in the backcountry, you can expect and we do expect to have huge avalanches in the backcountry. So it's really not a good time to be in the backcountry if that's what your thing is," said Mike Stanford. Stanford is an avalanche forecast supervisor for the Washington State Department of Transportation's north central region.
Stanford highly recommends skipping backcountry travel altogether this weekend.
"It's not a time to be in the back country and it's kind of in that shoulder season where it's just a dangerous time to be back there," he said.
For anyone planning a trip, ensuring you are checking conditions with the Northwest Avalanche Center, having a partner, and making sure you have gear and experience to use the gear is key.
Why avalanche danger will be high
This jump in temperatures will lead to increased melting of the snowpack and ice, which can create quite a bit of water flow on the top of and through the different layers of snow and ice. The increased waterflow increases the instability of the snowpack, as well as the ground beneath as water filters into the soil and rocks.
The snowpack will become unstable and wet avalanches and cornice falls are likely, according to KING 5 meteorologist Mike Everett.
This will be the case through the weekend and going forward as temperatures continue to warm and fluctuate through the spring and into early summer.
Avalanche risk is similar to the weather in that it can and does change almost daily.
Clearing mountain passes
The warming temps will help crews working to open state Route 20, though, Stanford said. He said there's about a week or week and a half of clearing to do.
"So the warm weather for us is a good thing," he said. "We want to get that hazard off the mountain down onto the highway before it's opens to the public."
As of Friday, crews had cleared the North Cascades Highway to milepost 154 at Swamp Creek.
In addition to avalanche control, crews will also need to make some repairs before the highway will open to traffic.
Hiking or biking past the closure is allowed, but travelers should keep the conditions in mind and be aware there's limited cell service in the mountains, WSDOT said.
