Another atmospheric river taking aim at Northwest
A moisture-laden storm will sock the Northwest through Friday, and some areas along the Interstate 5 corridor could receive nearly a month’s worth of rain.
By
Brandon Buckingham, AccuWeather Meteorologist
Published Nov 9, 2021 10:10 AM EST
|
Updated Nov 12, 2021 5:55 AM EST
This fall has featured frequent episodes of stormy weather along the West Coast, especially across the Pacific Northwest. In fact, it's been so stormy that the latest stats from the U.S. Drought Monitor show that drought conditions have been erased across western Washington.
The city of Seattle has now had two consecutive months of above-average rainfall, racking up 8.78 inches of rain, or roughly 159% of what is typically observed during that time. Through Nov. 11, the Emerald City has observed 4.37 inches of rainfall or about 198% of average through the first 10 days of the month.
Farther south in Portland, Oregon, the same streak of above-average rainfall has been observed over the past few months as well.
While both of these cities dealt with unsettled conditions into midweek as a storm slammed into the California coast, the atmosphere quickly recharged and sent a river of moisture into the Pacific Northwest beginning on Thursday.
Atmospheric river events along the West Coast, similar to the one that occurred in California in late October, can bring along intense rainfall rates that persist for hours on end. While this can be great to temporarily curb drought concerns, it can also host a slew of potentially hazardous conditions.
The risks of flash flooding, river flooding and mudslides may increase across western Oregon and Washington through Friday, as multiple days of rain are expected.
This next storm to target the Northwest began on Wednesday night and will continue through the day on Friday and could tally up nearly a month's worth of rain in some locations along the Interstate 5 corridor.
AccuWeather Chief Broadcast Meteorologist Bernie Rayno said the moisture from the incoming storm could be traced all the way to the tropical Pacific.
"This is gonna be a potentially very wet system and a very warm system," Rayno said.
Because of the stormy pattern as of late across the Pacific Northwest, the ground has had to work overtime in an attempt to soak up all the moisture. With the soil moisture profile nearly saturated, the ground cannot effectively absorb heavy rainfall, further increasing the risk for flooding.
Snow levels will remain high as this storm rolls ashore. All of the fresh snowpack that has built up below 5,000-6,000 feet in recent days may be threatened because the storm could drop precipitation as rain rather than snow and lead to additional flooding concerns.
Wednesday featured somewhat of a reprieve from precipitation across the Pacific Northwest, both in coverage and intensity, as Tuesday's storm slid inland. However, lingering rain and mountain snow showers still dotted the Cascades and the northern Rockies.
The arrival of the atmospheric river and subsequent steady rainfall began to drench western Oregon Wednesday night before spreading inland up the Columbia River.
The firehose of moisture then wobbled northward into Washington through the day on Thursday, expanding the flooding threat into places like Olympia, Tacoma and Seattle. After the arrival of rain into Washington state, it may be set to last through at least Friday before tapering off.
A general 3-6 inches of rain can be expected across the low-lying valleys of the Pacific Northwest from this storm. At higher elevations, rainfall amounts could ramp up significantly, perhaps to over a half of a foot along the western facing slopes, with an AccuWeather Local StormMax™ of 8 inches.
While the steadiest wet weather will taper to more widely scattered showers across the Pacific Northwest this weekend, the impactful weather from this storm will be far from over.
This storm will make a cross-country trek over the course of the weekend and into early next week. Cold air will likely be in place as this storm sweeps through the Plains, Midwest and even the Northeast, possibly bringing the first accumulating snow for those in its path.
For the latest weather news check back on AccuWeather.com. Watch AccuWeather Network on DIRECTV, DIRECTVstream, Frontier, Spectrum, fuboTV, Philo, and Verizon Fios. AccuWeatherNOW is streaming on Roku and XUMO.
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News / Weather Forecasts
Another atmospheric river taking aim at Northwest
A moisture-laden storm will sock the Northwest through Friday, and some areas along the Interstate 5 corridor could receive nearly a month’s worth of rain.
By Brandon Buckingham, AccuWeather Meteorologist
Published Nov 9, 2021 10:10 AM EST | Updated Nov 12, 2021 5:55 AM EST
This fall has featured frequent episodes of stormy weather along the West Coast, especially across the Pacific Northwest. In fact, it's been so stormy that the latest stats from the U.S. Drought Monitor show that drought conditions have been erased across western Washington.
The city of Seattle has now had two consecutive months of above-average rainfall, racking up 8.78 inches of rain, or roughly 159% of what is typically observed during that time. Through Nov. 11, the Emerald City has observed 4.37 inches of rainfall or about 198% of average through the first 10 days of the month.
Farther south in Portland, Oregon, the same streak of above-average rainfall has been observed over the past few months as well.
While both of these cities dealt with unsettled conditions into midweek as a storm slammed into the California coast, the atmosphere quickly recharged and sent a river of moisture into the Pacific Northwest beginning on Thursday.
Atmospheric river events along the West Coast, similar to the one that occurred in California in late October, can bring along intense rainfall rates that persist for hours on end. While this can be great to temporarily curb drought concerns, it can also host a slew of potentially hazardous conditions.
The risks of flash flooding, river flooding and mudslides may increase across western Oregon and Washington through Friday, as multiple days of rain are expected.
This next storm to target the Northwest began on Wednesday night and will continue through the day on Friday and could tally up nearly a month's worth of rain in some locations along the Interstate 5 corridor.
AccuWeather Chief Broadcast Meteorologist Bernie Rayno said the moisture from the incoming storm could be traced all the way to the tropical Pacific.
"This is gonna be a potentially very wet system and a very warm system," Rayno said.
Because of the stormy pattern as of late across the Pacific Northwest, the ground has had to work overtime in an attempt to soak up all the moisture. With the soil moisture profile nearly saturated, the ground cannot effectively absorb heavy rainfall, further increasing the risk for flooding.
Snow levels will remain high as this storm rolls ashore. All of the fresh snowpack that has built up below 5,000-6,000 feet in recent days may be threatened because the storm could drop precipitation as rain rather than snow and lead to additional flooding concerns.
Wednesday featured somewhat of a reprieve from precipitation across the Pacific Northwest, both in coverage and intensity, as Tuesday's storm slid inland. However, lingering rain and mountain snow showers still dotted the Cascades and the northern Rockies.
The arrival of the atmospheric river and subsequent steady rainfall began to drench western Oregon Wednesday night before spreading inland up the Columbia River.
The firehose of moisture then wobbled northward into Washington through the day on Thursday, expanding the flooding threat into places like Olympia, Tacoma and Seattle. After the arrival of rain into Washington state, it may be set to last through at least Friday before tapering off.
A general 3-6 inches of rain can be expected across the low-lying valleys of the Pacific Northwest from this storm. At higher elevations, rainfall amounts could ramp up significantly, perhaps to over a half of a foot along the western facing slopes, with an AccuWeather Local StormMax™ of 8 inches.
While the steadiest wet weather will taper to more widely scattered showers across the Pacific Northwest this weekend, the impactful weather from this storm will be far from over.
This storm will make a cross-country trek over the course of the weekend and into early next week. Cold air will likely be in place as this storm sweeps through the Plains, Midwest and even the Northeast, possibly bringing the first accumulating snow for those in its path.
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For the latest weather news check back on AccuWeather.com. Watch AccuWeather Network on DIRECTV, DIRECTVstream, Frontier, Spectrum, fuboTV, Philo, and Verizon Fios. AccuWeatherNOW is streaming on Roku and XUMO.
Report a Typo