A series of storms and rising levels of snow are forecast to heighten threats of flooding and landslides across the Pacific Northwest this week.
"The Pacific Northwest will continue to get pounded with heavy rain and flooding this week," said Paul Pastelok, AccuWeather's lead long-range meteorologist.
Rising creeks and streams, as well as already drenched grounds, will receive additional water as the rain falls. Furthermore, snowmelt from rain will further trigger a surge of water downstream.
Poor travel conditions and wet roadways are expected to the Interstate-5 corridor from Seattle to Medford, Oregon.
Through the late week, moisture is expected to remain focused at the Pacific Northwest. The heaviest rainfalls are forecast to hit western Washington and Vancouver Island in British Columbia, Canada.
"Widespread significant flooding is a big concern," Pastelok said.
An onslaught of storms and rising snow levels will contribute to a heightened danger of flooding and landslides across the Pacific Northwest this week: https://t.co/f9RnrNyW6W pic.twitter.com/LrP8ExpcgA— AccuWeather (@breakingweather) January 27, 2020
The storm train in the Pacific Northwest continues. @FeliciaCombsTWC & I have the latest on the impacts there and whether or not those storms could be cause for concern in the East this weekend. 9am-1pm ET on the @weatherchannel. pic.twitter.com/vid9qoEQM3— Alex Wallace (@TWCAlexWallace) January 28, 2020
Will Seattle get to see the sun anytime soon? An atmospheric river has been funneling moisture into the Pacific Northwest where it has rained everyday in Seattle since December 29th. In fact, there has not been a sunny day there since November 30th. https://t.co/TPqq9p2209 pic.twitter.com/q4uFnnONIx— CNN (@CNN) January 29, 2020
Rainfall totals through the week may reach 300 mm (1 foot) along the western foothills of the Cascades, and range between 76 to 152 mm (3 to 6 inches) nearer the coast.
"Motorists should exercise caution along secondary mountainside roads as debris may have washed onto the road surface or the road may have been washed away in some extreme cases," AccuWeather Meteorologist Brandon Buckingham warned.
Road closures are likely where mudslides or landslides have taken place.
Pastelok added that snow levels are expected to increase and exceed pass levels during the mid and late parts of the week. During this time, the risk of swelling rivers will be highest as rain and snowmelt combine. Mountain slopes may be more vulnerable to avalanches.
According to AccuWeather, this atmospheric river can result in a firehose effect of extreme precipitation in a narrow portion.
Meanwhile, weather will be milder during the first few days of February as colder and drier air moves southward across the Northwest, said long-range meteorologists.
Snow is likely to return to the lower elevations during the transition period from stormy to tranquil.
Featured image credit: NOAA/GOES-West, RAMMB/CIRA. Acquired January 29, 2020, at 13:30 UTC