Atmospheric River Storms Target the Pacific Northwest: Flood Risk, Strong Wind and Mountain Snow Through Nov. 14
A series of atmospheric river storms is set to hit the Pacific Northwest this week, bringing a risk of flooding, damaging wind and feet of mountain snow from Washington to Northern California, with heavier totals over the border in British Columbia. Meanwhile, slow-moving downpours threaten flash flooding in South Texas, and colder air may bring the season’s first snowflakes to parts of the Great Lakes, Ohio Valley, Appalachians and New England by late week. Here is what is forecast, who is affected and what comes next.
Key Takeaways
- Pacific Northwest: Rounds of rain, wind and mountain snow run through Saturday, Nov. 14. Forecasters flag “some risk of major flooding” from southwestern Washington to Northern California in the second half of the week.
- Rain totals: More than a foot is possible in parts of western Washington and coastal British Columbia through Nov. 14, with peak rates of 1–2 inches per hour.
- South Texas: 4–8 inches of rain is forecast in far southern Texas, with a local maximum near 13 inches; San Antonio, Laredo, Corpus Christi and Brownsville are in the flood-risk zone.
- East and Midwest: A late-week storm, Thursday through Saturday, could bring first snow to northern areas and a first hard freeze to parts of the South.
All forecasts below come from AccuWeather meteorologists as of Nov. 8–9 and may change. Residents should follow their local National Weather Service office for official watches and warnings.
What Is Happening: An Atmospheric River Train in the Northwest
An atmospheric river is a long, narrow plume of moisture that can deliver heavy rain or snow when it reaches land. According to AccuWeather senior meteorologist Alex Sosnowski, a series of these storms will move ashore in rounds this week, separated by short breaks.
Timeline
| When | What is forecast |
|---|---|
| Mon. night–Tue., Nov. 9–10 | Next storm arrives, mainly affecting western Washington and British Columbia. |
| Wed., Nov. 11 | Brief burst of warmth, with temperatures near record levels in parts of the Northwest. The strongest storm of the series reaches Vancouver Island. |
| Thu.–Sat., Nov. 12–14 | Multiple rounds of rain and mountain snow spread across Washington, western Oregon and parts of Northern California. Colder air could push snow into Northern California’s mountains. |
Rain, Wind and Snow by the Numbers
- Rain: More than 12 inches is possible in parts of western Washington and coastal B.C. through Nov. 14, especially on west- and south-facing slopes.
- Wind: Several rounds of strong wind along the coast and through mountain passes could cause power outages and make driving dangerous for trucks, RVs and other high-profile vehicles. Rough seas and large breaking waves are expected along the coast.
- Snow: In Washington’s Cascades and Olympics, snow is mainly expected at the highest elevations. The heaviest snow, possibly 10–20 feet, is forecast for British Columbia’s Coast Mountains.
Who Is Affected
The main U.S. impact zone covers western Washington, the Cascade and Olympic mountains, western Oregon and the mountains of Northern California. AccuWeather storm warning meteorologist Jean-Marc Rampersad said the risk of major flooding extends from southwestern Washington to Northern California in the second half of the week. Senior storm warning meteorologist Tim Richards said runoff will increase with each storm as the ground becomes saturated, making flooding in small streams and rivers more likely.
Other risks named in the forecast:
- Urban flooding where fallen leaves clog storm drains.
- Mudslides and debris flows at lower and middle elevations, especially in areas burned by recent wildfires.
- Avalanche danger in the mountains from midweek on.
- Travel disruptions from flooding and strong winds.
A Drought-Relief Upside
The storms arrive after a dry stretch. AccuWeather said rainfall from late summer through Nov. 6 was only 25% to 75% of the historical average across much of the region. Rain that falls without flooding could ease the deficit, and mountain snow could help rebuild the snowpack that supplies water later in the year.
South Texas: Flash Flood Risk
Far from the Northwest, AccuWeather meteorologist Renee Duff reported that slow-moving downpours are raising the flash-flood risk across South Texas. Forecast rainfall:
- 1–2 inches from the Texas Hill Country to the Rio Grande Valley
- 4–8 inches in far southern Texas, with a local maximum of about 13 inches
- Flooding risk centered on San Antonio, Laredo, Corpus Christi and Brownsville
East and Midwest: First Snowflakes and a Hard Freeze
A late-week storm, Thursday through Saturday, could bring the first snow of the season to parts of the Great Lakes, Ohio Valley, Appalachians and New England, according to AccuWeather meteorologist Brandon Buckingham. Colder air could also bring the first hard freeze to parts of the South. Gardeners and anyone with exposed pipes or outdoor plants should watch local freeze warnings.
What Happens Next
- Watches and warnings: NWS offices serving the Northwest and South Texas will issue flood, wind and winter weather alerts as needed as the timing becomes clearer.
- Mid-November pattern: AccuWeather expects colder air to spread across more of the western U.S. by mid-November, starting a snowier stretch that would benefit ski resorts.
- Holiday travel: Anyone driving mountain passes in the Northwest or traveling for Veterans Day on Wednesday should check state transportation department road reports before leaving.
How to Prepare
- Sign up for local emergency alerts and keep a phone charged in case of power outages.
- Clear leaves from storm drains and gutters near your home.
- Never drive through flooded roads. Turn around, don’t drown.
- Residents near recent burn scars should know their evacuation routes.
Official preparedness guidance is available at Ready.gov/floods.
Related Coverage
- Four Corners Flooding: Record San Juan River Levels Damage Hundreds of Homes
- The Week Ahead (Nov. 9–15, 2026)
- Week in Review (Nov. 2–6, 2026)
Sources
- AccuWeather — Atmospheric rivers to bring flood risk, strong winds to Northwest (updated Nov. 9, 2026)
- AccuWeather — Flash flood risk across South Texas (updated Nov. 8, 2026)
- AccuWeather — First snowflakes possible in central and eastern U.S. (Nov. 8, 2026)
- National Weather Service
- Ready.gov — Floods
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