It has been a wonderful past few days for mountain snowfall, and we have gobs of additional snow on the way this week! I was skiing in Whistler from the 14th through the 18th, and although the first two days were sunny and the third was rainy, the 17th and 18th had heavy snow all day long. Though the alpine lifts were closed due to high avalanche danger and blizzard conditions, we were able to find some incredible powder stashes in the glades and I had some of the best turns of my life.
A strong cold front is currently swinging through the region, bringing heavy rain/mountain snow and strong winds to some areas. Steady rain should end within the next hour over the Portland region, but post-frontal showers will continue tonight into Monday, with the heaviest and most frequent showers occurring further north in Washington. With moderate WSW flow aloft, we’ll see enhanced precipitation along the western slopes of the Cascades/Olympics/Coast Range and another round of moderate-to-heavy snow above 2,500-3,500 feet.
A quick look at the combined wind speed/air pressure plot from buoy 46029 shows the dramatic rise in pressure/drop wind wind speed after the passage of the cold front. This is the textbook signature of a vigorous cold front. The peak gust of 49 knots (56 mph) is pretty impressive as well. I believe that 58 knot gust measured on the 18th is faulty data.
Paradise is certainly looking like a winter wonderland right now, and the Cascades are currently under a winter weather advisory for 4-11 inches of snow through Monday morning, with less further south and more further north. The Olympics and North Cascades of Skagit and Whatcom Counties are under a winter storm warning and are expected to pick up 1-2 feet, with locally higher amounts near Mt. Baker.
Thankfully for skiers, snowboarders, and water resource managers, our snowy mountain weather is expected to continue this week as a string of systems swing through the area. After a temporary respite from the rain Monday night, another system will bring a combination of wind, rain, and mountain snow on Tuesday. The trailing cold front from this system will stall over Southern Oregon/Northern California Tuesday night into Wednesday morning, giving them a much needed boost to their snowpack. Meanwhile, the parent upper-level trough will keep showers over the region through Friday afternoon, keeping temperatures a several degrees below average in the lowlands and allowing snow to continue to pile up in the mountains.
The 72-hour snowfall amounts from 4 am today-4am Wednesday and 4am Wednesday-4am Saturday are very impressive. The Thursday morning-Friday night time period looks especially fantastic, as snow levels should only be around 1,000 feet, allowing for light and fluffy snow at the resorts instead of the “Cascade Concrete” we are so used to. If you’ve ever wanted to play hooky and go skiing, this is the week to do it.
Alas, all good things must come to an end, and the models show us transitioning to a milder, atmospheric river pattern by next week.
Have a good week,