A train of storms will pound the northwestern United States with flooding, dangerous surf and hurricane-force winds into early next week.
The most severe impacts will be felt from southwestern British Columbia through western Washington and Oregon and into northern California as several Pacific storms barrel onshore through Tuesday.
Residents in and around these areas should be aware of the threat for urban and coastal flooding, mudslides, washed-out roads, power outages, property damage and travel disruptions during the onslaught.
Initial wave of rain, wind to last into Friday
The first wave of heavy rain and wind will continue to press inland across the Northwest into Friday.
The bulk of the rain will focus along the Interstate 5 corridor from Seattle to Redding, California.
Flooding is expected to mainly occur on a localized level during this initial push of moisture.
Some rain is expected to reach as far south as San Francisco, where the first measurable rainfall (0.01 of an inch or greater) since May 8 will fall.
The combination of rain, wind and poor visibility could make travel very hazardous on area highways.
The rain will be wind-swept at times, with gusts generally ranging from 40 to 60 mph across the region. Gusts up to 80 mph can be expected along the immediate coast and over the mountains.
Once-Super Typhoon Songda to unleash hurricane-force conditions this weekend
As quickly as the first storm exits, the second, more powerful storm will follow on its heels from Saturday to Sunday.
This next storm will contain the remnant circulation of once-Super Typhoon Songda, which curved away from Japan earlier this week.
While the storm is not expected to be tropical in nature by the time it reaches the Pacific Northwest, the impacts could still be similar to that of a hurricane, according to AccuWeather Senior Meteorologist Alex Sosnowski.
Gusts from 75 to 100 mph will occur in some coastal areas. Tree and power line damage and power outages are likely.
"The storm this weekend could hit some areas like a sledgehammer," Sosnowski said.
"The heaviest rain and highest winds will come onshore Saturday afternoon along the Washington, Oregon and northern California coasts," according to AccuWeather Senior Meteorologist Dan Pydynowski. "A general 2 to 4 inches of rain will fall across the region, with higher amounts in the coastal ranges."
"Flooding will certainly be a concern after much of this same region is getting inundated with several inches of rain to end the workweek," he added.
Residents should clear debris out of storm drains to help prevent an overflow of water onto streets and lands.
Motorists should prepare for slow travel and possible road closures. Never attempt to drive through a flooded roadway as the water may be higher than it appears and the roadway underneath could be compromised.
Seas will quickly build to dangerous heights ahead of the storm. Serious beach erosion and coastal flooding can occur along the Washington, Oregon and northern California coastlines.
"The strength of the storm will cause waves to rise to over 30 feet offshore," according to AccuWeather Meteorologist Ryan Adamson.
While flooding rain and pounding surf will be a concern across the lower elevations, heavy snow will whiten the highest elevations of the Northwest.
Storm train to continue into next week
With the dry season officially over in the Northwest, there are no signs of the stormy pattern letting up any time soon.
Cumulative rainfall through Tuesday of next week will top 12 inches in some coastal areas with the potential for 18 inches in a few locations from northwestern California to the Olympic Peninsula of Washington," Sosnowski said.
Following the storms through this weekend, several more rounds of stormy weather will impact the region next week, Adamson said.
While the storms next week will generally be weaker, any additional rain could aggravate ongoing flooding problems or create new ones.