After a week of calm weather, a fresh storm will push into the northwestern U.S. for the middle of the week.
“After a much-needed break from the rain across California, stormy weather will return once again by the middle of the week,” AccuWeather Meteorologist Brett Rathbun said.
As the incoming storm approaches the West Coast, moisture will be drawn northward, promoting widespread snow showers throughout the interior Northwest beginning late on Monday night.
As the first bands of Pacific moisture slam into the West Coast, rounds of rain can be expected to impact cities from Portland to San Francisco by Wednesday afternoon.
Tranquil coastal conditions will also give way to gustier weather by the end of the day on Wednesday.
By Thursday, snow is expected to blanket much of Montana, northwestern Wyoming and the higher elevations of Idaho, Washington and Oregon. Lower elevations, such as the Snake River Valley and parts of eastern Oregon, can anticipate a mix of rain and snow.
Waves of rain will blow across the coastal regions, including Seattle; Portland and Medford, Oregon, and San Francisco, Sacramento and Fresno, California. A stray afternoon shower or two could even bring some sprinkles to downtown Los Angeles.
“The rain will not be as heavy as the previous storms, however, enough rain could lead to localized areas of flash flooding,” Rathbun said.
Reminiscent of past weeks, flooding may threaten northwestern California and the eastern edge of the San Joaquin Valley, where rainfall is expected to be heaviest.
Even with modestly gusty winds, falling trees could again block roads and cause power outages toward the end of the week as the ground becomes more saturated.
Snow will once again pound the high terrain of eastern California.
“A few feet of snow can fall across the Sierra Nevada,” Rathbun said.
While those in the Sierras have been buried multiple times this winter by yards of snow, any addition to this healthy snow pack is welcome after years of drought.
“This will continue to help replenish the reservoirs for the dry summer months,” Rathbun said.
However, the precipitation also poses a threat to transportation, such as potential travel delays as coastal winds increase and visibility drops amid heavy rain.
“Those traveling on Interstate 5 from Seattle to Sacramento, California, should be prepared for rainy spells and reduced visibility,” AccuWeather Meteorologist Renee Duff said.
While the atmosphere over the interior Northwest will be lacking in moisture by Friday afternoon, rain and mountain snow will persist in California and western Oregon through Friday night.