‘Unrelenting cold:’ Cold Weather Advisory extended as wind chills drop as low as 15 degrees

Update 6:20 a.m. Wednesday: As the Puget Sound region fends off an unusually bitter cold snap this week, the National Weather Service (NWS) extended its Cold Weather Advisory warning through Thursday, Feb. 13. Seattle weather could hover near record lows with “very cold wind chills as low as 15 to 20 degrees,” according to NWS Seattle.

With winds expecting to reach 3-10 mph Wednesday, it will feel like the temperatures have dropped into the single digits and teens despite deceptive blue skies and very little overcast weather. The Cold Weather Advisory is in effect until noon Thursday. Highs should make it into the upper 30s and lower 40s.

“Temperatures (Tuesday) morning (6 a.m.) were the coldest so far this year for many Washington locations,” University of Washington (UW) atmospheric sciences professor Cliff Mass explained on his blog. “Temperatures dropped into the twenties and teens over western Washington, while single digits and even below-zero temps were observed in eastern Washington.”

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Additionally, there is a Wind Advisory for the Cascade Foothills starting at 7 p.m. until noon Thursday — the same time the Cold Weather Advisory is expected to end.

Residents in areas including Seattle, Bellevue, Everett, Tacoma, and Bremerton should prepare for very cold wind chills, with temperatures potentially dropping as low as 15-20 degrees Fahrenheit.

NWS advised to keep all pets indoors and to check on older family members, friends and neighbors. It’s also crucial to use portable heaters correctly and avoid using generators or grills inside to prevent carbon monoxide poisoning.

“Very cold temperatures can lead to hypothermia with prolonged exposure and will impact vulnerable populations such as the homeless, pets and those without adequate access to heating,” NWS Seattle noted in their advisory.

This is one of the coldest mid-winters in decades

This cold spell is part of a broader pattern affecting much of the Pacific Northwest.

Mass noted that this has been one of the coldest mid-winters in decades for the region. He attributes the prolonged cold to a persistent atmospheric pattern known as an “omega block,” characterized by a high-pressure ridge offshore flanked by low-pressure troughs. This configuration channels cold, northernly air into the area, leading to sustained lower temperatures.

The current cold snap is expected to persist through Thursday afternoon. Record-breaking lows are possible during this period. A weather system is expected to hit Oregon and the southern part of Washington Thursday afternoon and evening, even lingering into Friday morning.

More MyNorthwest weather updates: Western WA snow fades, but freezing temperatures, ice persist

According to KIRO 7 meteorologists Morgan Palmer and Nick Allard, around Western Washington, very dry air will be in place as precipitation falls on Thursday afternoon and evening, which could cause some minor amounts of dry snow across Lewis and southern Pierce and Thurston counties. A dusting of snow could occur around Hood Canal Thursday night as well.

“Friday morning, we will still have some light snow mainly across the southern one-third of the area, but it will be moving out by mid-morning,” Allard reported. “I’ve seen some computer models put totals around a dusting to an inch, and I’ve seen some models put at least a couple of inches.”

As the weekend approaches, temperatures are expected to gradually warm.

Contributing: Frank Sumrall, MyNorthwest; KIRO 7

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