Holiday travelers had lots to contend with ahead of Thanksgiving, as an unusual storm known as a "bomb cyclone" hit Southwest Oregon and California Tuesday, reaching speeds of 90 miles per hour in places.
Its effects were felt in Washington on Wednesday.
The difference in atmospheric pressure caused high winds along the Tacoma Narrows Bridge and as far north as Skagit and Whatcom counties, where the gusting was expected to continue through Thanksgiving morning.
KNKX weather expert Cliff Mass says winds of this magnitude come about once a year, but the rapid-fire setup that gives a storm like this its name is extremely unusual — as well as the way it came in directly from the west.
“We rarely see this kind of bomb-like development off our coast," said Mass, a professor of atmospheric sciences at the University of Washington. "It went from virtually nothing 24 hours before to a full-blown system.”
The cold northerly flow coming through the Fraser River gap Wednesday topped 40 miles per hour in places and was spreading into the San Juan Islands and the northern Olympic Peninsula. Gusty winds from the east and northeast also were expected in the foothills of Cascades.
Despite the wind in places, Washington’s weather was already mellowing out on Wednesday, yielding to cool, sunny skies. Thanksgiving is expected to be clear, dry and quite cold.
Mass warned of a potential risk of lowland snow from Oregon to Southwest Washington on Sunday as a weather system moves in that could complicate travel home on the holiday weekend. But he said on Wednesday it’s still to early to know for sure.
Mass says generally speaking, Northwest travelers can count themselves lucky this year.
“In total, this is actually a very benign Thanksgiving — much drier and less windy than normal,” Mass said. “This is normally the windiest, rainiest time of the year.”
Weather with Cliff Mass airs at 9:02 a.m. Friday, right after BirdNote, and twice on Friday afternoons during All Things Considered. The feature is hosted by KNKX environment reporter Bellamy Pailthorp. Cliff Mass is a University of Washington professor of atmospheric sciences, a renowned Seattle weather prognosticator, and a popular weather blogger. You can also subscribe to podcasts of Weather with Cliff Mass shows, via iTunes or Google Play.