From windy Saturday to wintry Sunday as some places get slammed with snow
SEATTLE -- The weekend weather pattern has rapidly shifted from warm and windy to cool and wintry, leaving some communities buried under several inches of snow.
A Convergence Zone that stalled over northern Snohomish County and parts of Island County brought over 4-6 inches of snow as of early Sunday morning to areas such as Granite Falls, Marysville and Arlington.
As much as 8-9 inches of snow could fall there before the zone fizzles. A Winter Storm Warning remains in effect for Everett and the northern half of Snohomish County until noon for another 1-3 inches on top of what's already fallen.
Snohomish PUD reported about 15,000 people without power in the northern half of the county -- likely from heavy snow.
The area around Port Angeles and Sequim were also getting more than a few inches of snow as cold air runs into the Olympic Mountains and creates a localized snow belt.
Light snow was falling in several other areas, but accumulations were expected to remain relatively light, with a Trace to 2" as a general rule, maybe three inches in spots as a cold trough of low pressure swings by offshore to our south then heads inland around Portland later in the morning. Snow hit I-5 around Chehalis, causing a semi truck to jackknife. No word if anyone was hurt.
Snow will taper off from north to south as the day progresses.
Winter Weather Advisories remain in effect until late morning for the areas north of Everett and the Olympic Peninsula until noon, while they remain in effect until 4 p.m. In the South Sound and Southwestern Washington as the low slides by there later this afternoon. The greater Seattle-Bellevue-Bremerton area was one of the snow losers, with moisture being blocked by the Olympic Mountains.
Meanwhile, dry arctic air has begun blowing into Western Washington via the Fraser River Valley. Northeast winds gusted as high as 48 mph early Sunday morning with gusts as high as 50-55 mph continuing there through the day. Wind Advisories are in effect for Whatcom County and the San Juan Islands through 10 p.m., as temperatures hover in the 20s to low 30s there.
Bellingham Airport reported flight delays due to icy conditions on the runways.
That strong north wind will eventually spread to the south on Sunday, bringing gusts to 25-40 mph in the Puget Sound region and, as mentioned, up to 50-55 mph near the Fraser River outflow.
The north wind is somewhat unusual and can cause damage at lower speeds because our trees are more accustomed to southerly winds. Strong north winds could also force the closure of the westbound lanes of the I-90 Floating Bridge.
"If we hit a new threshold of sustained winds from the north of at least 25 mph (that north detail is very important and does not happen often) for two minutes and observe waves of at least 2 feet, we will not allow traffic onto the westbound I-90 bridge between Mercer Island and Seattle," the WSDOT wrote Saturday. "Wind and wave analyses performed during Sound Transit's East Link design process showed the pontoons on the westbound I-90 bridge are susceptible to damage during strong north wind events."
The WSDOT says it will get the word out via the web and social media if it needs to close the bridge for winds. Highs will be in the 30s.
Snow showers will taper off by the afternoon and we'll see clearing from the north as temperatures begin to fall. Sunday night into Monday morning will be clearing but cold with breezy north winds. Lows will drop into the teens to mid 20s around Seattle, with wind chills in the teens to single digits in the windier spots.
Monday will be sunny but cold and breezy with north winds continuing. Any snow on the roads will have frozen and icy roads are a concern for Monday morning. Highs will be in the 30s.
The north wind will taper off Monday evening, leaving another clear and cold night that will be a few degrees colder than Sunday night, dropping again into the teens to low 20s. Dry weather continues Tuesday.
Another chance of light snow returns for mid week.