Stormy Thanksgiving on Tap

Thanksgiving Week is, on average, the stormiest week of the year for the Pacific Northwest. And luckily for storm geeks and snow lovers across our region, Turkey Day 2016 will live up to its stormy reputation as a cyclone bringing strong winds, heavy rain, and heaps of mountain snow slams into the Pacific Northwest. That’s something to be thankful for!

Let’s start out by taking a look at the watches, advisories, and warnings currently in effect for both Western Washington and Western Oregon.

It’s been months since we saw the those wonderful shades of pink over the mountains! The mountains have already picked up some snow, and a LOT more is in store for this morning and tonight (there will be a slight afternoon lull). Storm totals from Wednesday night to Friday morning will reach 1-3 feet for many areas, with the passes likely on the lower end of that spectrum and favored locations like Mt. Baker ski resort and Paradise Ranger Station on the higher end.

It won’t just be white in the mountains. It will be wet in the lowlands too. 48 hour totals from 5 pm Wednesday to 5 pm Friday will approach 1 inch in the Puget Sound region, and the Willamette Valley could see 2-4 inches during this time frame. The Central Oregon coast will get absolutely slaughtered, with exposed locations like Mt. Hebo picking up close to 10 inches. Much of Western Oregon is currently under a flood watch, but any flooding should be minor since snow levels are relatively low; near 2,500 feet in the North Cascades and 4,500 feet for the Central Oregon Cascades.

Interestingly, this storm has some characteristics of the “atmospheric rivers” that bring sky-high snow levels and major flooding with a long, narrow plume of moisture stalling over the region and dousing us with rain. The difference is that this storm originated over the Northern Pacific (where water temperatures are still much cooler than normal), not the subtropical Pacific near Hawaii. The wet and warm atmospheric rivers are known as “Pineapple Expresses” (there are lots of Pineapples in Hawaii). I don’t know what to call this one… suggestions are welcome.

We see a brief break Friday afternoon, but yet another system comes into the area Friday night into Saturday. This system will be weaker with only a couple inches expected for most locations. Another weak system slips down from the northwest Sunday evening, but while rainfall totals in the lowlands will be low, westerly flow behind the front will keep snow going in the Cascades with amounts from 6-12 inches possible. A stronger storm is slated for Tuesday of next week, bringing yet another round of heavy snow to the passes.

The extended looks looks cool and wet with periods of moderate-to-heavy snow in the mountains. Models keep building a strong ridge in the NE Pacific with a trough over our area, giving us cool and unsettled NW flow. This is a classic La Nina pattern.

Whistler opened yesterday, Blackcomb opens today, and both Crystal & Mt. Baker open tomorrow. I suspect the lower elevation resorts like Stevens and Snoqualmie will open next week.

Have a great Thanksgiving! If traveling across the passes, Friday afternoon will be your best bet, but still be prepared for icy conditions and delays.
Charlie