Potent storm packing wind and rain risk to target Northwest
An impactful storm will hug the Pacific coast with wind and rain for the Northwest into Friday.
Video from the Seattle, Washington, area shows lightning flickering in the night sky on March 26.
A storm from the Pacific will slice northward along the coast but onshore enough to have significant impacts on the northwestern United States through the late part of the week, AccuWeather meteorologists warn. The storm will follow unseasonably warm conditions, including some record-high temperatures in some locations.
Record-challenging warmth ahead of storm
Temperatures soared across the Northwest on Tuesday and Wednesday. Seattle and Tacoma, Washington; and Portland and Eugene, Oregon, set daily record highs on Tuesday.
Farther inland, east of the Cascades, temperatures climbed into the 70s and 80s yet again on Wednesday. A number of daily record highs were either challenged or broken. Portland, Oregon reached 82 degrees, beating its previous daily record. Spokane, Washington also reached 75 degrees, beating its daily record of 67, which was set in 1946.
In Boise, Idaho, the temperature reached 81 degrees, which was 1 degree shy of the record that has held up for nearly 150 years (1877).
Storm's rain, wind to concentrate on Pacific coast
The storm will pack strong winds along the Washington and Oregon coasts, as many Pacific storms often do. Wind gusts from the storm can be strong enough to break weak tree limbs and cause poorly rooted trees to topple, leading to sporadic power outages.
A plume of moisture, sometimes referred to as an atmospheric river, will create a persistent zone of heavy rain along the Washington, Oregon and Northern California coasts.
The heaviest and steadiest rain is likely to occur from Thursday to early Friday, with a general 2-4 inches along the immediate coasts and along the lower west-facing slopes of the Cascades and Siskiyous. However, higher amounts of 6-8 inches can occur in the rainiest spots. From 0.75 of an inch to 1.50 inches of rain is likely to fall along the Interstate 5 corridor.
Very little rain is likely to fall east of the Cascades.
With the uptick in storms over the past month or so, the ground has become wet from coastal areas to the western slopes of the Cascades. As more heavy rain pours down with the new storm, runoff can lead to flash flooding and mudslides that may not be limited to recent burn scar locations.
Unlike most storms thus far this year, this storm will have a significant amount of warm air on its front side. The warmth will result in snow levels well above the passes for most of the storm.
Rain will fall high up into the elevations of the Cascades, leading to excessive runoff as snow melts along with the rain. The warm conditions during the first part of the storm can also increase the risk of avalanches.
New storm on deck for next week
Yet another storm is forecast to roll ashore next week along the Pacific coast.
"The storm lurking for next Tuesday and Wednesday is just as dynamic as the one for the middle and latter part of this week," Gilman said, "But next week's storm looks to be farther south, which can bring heavy rain and gusty winds through the Central California coast, including San Francisco."
While the track of storms this far out can shift, some data suggests that showers from next week's storm could reach as far south as Los Angeles and San Diego where more rain is needed to help with topsoil moisture heading into the hot, dry weather season.
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