Multiple storms will hit the Pacific Northwest into next week, with a “Pineapple Express”-type atmospheric river storm possible to produce several inches of rain early next week, causing river flooding.
Anticipate a string of atmospheric river storms that will bring heavy rain to Seattle and the Western Washington region through Wednesday. (Source: Fox News)
Expect Catastrophic Floods on Rivers
Over the next few days, atmospheric river storms will dump several inches of rain on the Pacific Northwest and threaten moderate to catastrophic flooding on multiple rivers. Friday to Saturday’s storm brought several inches of snow to the Cascades, including over a foot at Mt. Rainier’s Paradise Ranger Station. After 30 semi-trucks spun out on snowy roads, Interstate 90 via Snoqualmie Pass in Seattle was closed for an hour on Friday morning. The Washington State Department of Transportation said that road crews were cleaning other slick highway incidents. Friday brought a couple of inches of snow to Eastern Oregon and Washington. The Washington State Patrol reported that a motorist lost control on a snow-covered road and hit a tree in rural Stevens County, northern Washington, killing one person. Central and Eastern Washington troopers reported 25 snowy road crashes, including more than a dozen in Tri-Cities. Rain and mountain snow are expected until late Saturday, with snow showers in the mountains.
Winter Storm Warnings are in place until Sunday morning along the whole spine of the Cascades in Washington and Oregon, including all heavily used mountain routes around Seattle and Portland, for 1-3 feet of snow. According to FOX Forecast Centre, Pacific moisture streaming out of the Pacific Northwest will reach the windward slopes of the Intermountain Region, threatening significant snow in the Great Basin and Rockies. By early Monday, higher terrain in Idaho, western Montana, northern Utah, northwest Wyoming, and northwest Colorado will receive 1 to 3 feet of snow, with winter weather advisories. Saturday morning’s storm’s 35-50 mph winds may blast snow in the mountains and cause power outages in the lowlands. Early Saturday morning, 16,000 Western Washington residents lost power, including 13,000 in Seattle. Trees fell along Highways 101 and 112 west of here due to strong winds.
“For many of you that have kids going to university on the other side of the state, this is not going to be the weekend for them to travel home,” FOX Weather Meteorologist Britta Merwin cautioned. “You’re going to want to tell them to just stay there and have a weekend with your friends instead of heading back home.” On Sunday, the jet stream pushes two warmer, tropically infused atmospheric river storms into the Pacific Northwest, replacing the mountain snow threat with severe rain and flooding. The first atmospheric river will raise snow levels to about 5,000-6,000 feet on Sunday afternoon and Sunday night, with showers extending into Monday. The storm is nicknamed the “Pineapple Express” because a second, stronger air river is projected to dip into abundant warm, tropical moisture near Hawaii hours later. By late Monday and Tuesday, several inches of rain will raise snow levels in the lowlands and mountains to over 7,000 feet. Some mountain locations might experience 10 inches of rain between the two atmospheric rivers, while the Seattle and Portland metro areas could have 3 to 5 inches, causing flooding on various rivers and urban floods around the city centers. Many Northwest rivers are experiencing minor to severe flooding, with the Snoqualmie and Skagit Rivers in Washington likely reaching major flood stage by midweek. The Pineapple Express storm also increases mountain avalanches and flash flooding with landslides or debris flows in recent Cascade wildfire burn scars.
