Wind, Rain, Mountain Snow, and Big Waves this Week!

After a brief break this weekend, the coming week will feature the classic quadfecta of winter weather: rain, wind, mountain snow, and big waves on the coast. As far as mountain snow goes, I couldn’t be happier, as I’m heading up to Whistler tomorrow and am looking forward to a snowy week up there. And with colossal waves off the coast, Mavericks, a big-wave surf break off Pillar Point in Half Moon Bay, California, may get the green light on Thursday with their annual contest as part of the World Surf League’s Big Wave Tour. 

We are tracking two main systems this week: one on Tuesday and an even stronger one Wednesday/Thursday morning

Tuesday’s Storm: 

After a calm Sunday/Monday with only a few passing high clouds, clouds will start to thicken Monday afternoon (earlier for the Portland metro area) as a shortwave develops to the south of a deep low offshore and approaches the area.  

Precipitation will begin to increase Monday afternoon and persist through Tuesday evening, with .25 to .5 inches likely for most of the lowlands and snowfall amounts ranging from a couple inches in the Cascades to a foot in the higher elevations of the BC Coast Range. Additionally, a good chunk of the Intermountain West should get some snow from this system, giving them a much-needed, albeit meager, boost to their snowpack. 

The long period of moderate southerly winds off our coast associated with the deep low far offshore and enhanced by the surface shortwave traveling closer to the area will support the formation of large waves. However, at “only” 15-20 feet (much larger at the Mavericks surf break!), these waves won’t be large enough for the competition at Mavericks. But with large swells and relatively little chop, it should be a fantastic day to watch the waves break against the shore – and if the wave orientation is right (i.e. the waves hit the beach at an angle instead of hitting it straight on) it could perhaps a great day for some very daring surfers (I do not know the idiosyncrasies of most surf breaks along the Pacific Coast). I wish I was at my uncle’s place in Pacific City to witness the waves! 

Wednesday/Thursday morning’s Storm 

A much stronger system Wednesday will bring heavy snow to the mountains, strong wind/waves to the coast, and moderate-heavy rain to the lowlands. Take a look at the image above showing the clearly-defined fronts as the parent low stalls far offshore Wednesday morning. 

This storm has impressive pressure gradients both ahead of and behind the warm front, and I expect gale and perhaps storm warnings to go into effect for the coast during the day Wednesday and persist into Thursday. The swells reaching Mavericks on Thursday should be high enough for the surf competition to take place, but stormy weather and brisk winds are expected to reach south into Central California as well, raising the potential for chop on the wave faces. Big wave surfers obviously want giant swells, but they also want smooth faces with very little/zero chop, and smooth faces don’t look too likely at this point. We’ll see what the World Surf League decrees.  

The thing that excites me the most about this storm is how much snow it could drop in Whistler. Since Whistler and much of the Washington Cascades are predicted to only spend a very brief amount of time in the storm’s warm sector, snow levels should remain relatively low, allowing snow to fall down to 2,000-foot Whistler Village throughout the event. Current models have the snow beginning to fall Wednesday afternoon and keep it dumping through Thursday evening. Storm totals are nothing short of delightful – 1-2 feet throughout the BC Coast Range, Cascades, and Sierra Nevada, and plenty of snow in the Intermountain West.  

 With cool, unstable onshore flow following Thursday’s storm and another deep low slated for the weekend, it looks as though the mountains will stay snowy for some time to come. We sure took our time getting started on our snowpack this winter, but I expect us to make some serious gains over the next week or two! 

Have a great rest of your weekend! I may have an update from Whistler if I’m not too busy skiing and exploring the village.  

Charlie