Washington is about to trade its driest stretch of autumn for a conveyor belt of Pacific storms. FOX Weather reported on Wednesday, November 4, that a newly developed storm system will sweep across Washington and Oregon beginning Thursday and continuing through Sunday, bringing heavy rain, gusty winds and mountain snow to the Cascade region — and federal forecasters at NOAA's Climate Prediction Center (CPC), in a hazards outlook issued the same day, put parts of the Pacific Northwest at a moderate risk of heavy precipitation again next week, from Thursday, November 12, through Sunday, November 15, with flooding possible. Two separate forecast sources, published hours apart on Wednesday, describe the same pattern from two distances: a wet week immediately ahead, and a second, more organised atmospheric river possible behind it.
Source: FOX Weather (Nov. 4, 2026, 3:25 p.m. EST)
The immediate numbers are these: the heaviest rain is expected across the Olympic Mountains, where up to 5 inches is possible through the weekend wave, while Seattle, Tacoma and Bellingham are expected to receive about 1 to 2 inches, with some higher amounts possible, FOX Weather reported, citing the FOX Forecast Center. Snowfall will be limited to higher elevations across the Cascades, where up to 6 inches is possible. The setup is a strong low-pressure system expected to develop Thursday in the Gulf of Alaska, sending an atmospheric river — a long corridor of concentrated Pacific moisture — straight at the Pacific Northwest coast.
Source: FOX Weather (Nov. 4, 2026, 3:25 p.m. EST)
An atmospheric river is a narrow band of very moist air carried onshore from the Pacific; it is a normal part of the Northwest's rainy season, not a single named storm. The CPC outlook measures the chance of hazardous weather, not guaranteed totals — the agency has released no rain or snow totals for the Nov. 12–15 window, and said models still disagree on strength, timing and reach, which is why the risk sits at moderate, not high.
Two waves, two forecasts
FOX Weather described the first wave in day-to-day terms: the pattern will rotate a series of storms through Western Canada, fuelling persistent rain and snow farther downstream in the Northwest, beginning Thursday and continuing through Sunday, and the active pattern continues into next week with additional systems keeping conditions wet. Men's Journal, reporting the CPC outlook, described the second wave in risk terms: forecasters can now pick out at least two waves of moisture, one starting late this week and another early next week, and the Weather Prediction Center said in its November 4 extended forecast discussion that a deeper trough over the eastern Pacific early next week could set up 'a more organized atmospheric river event,' with showers spreading into California and stronger winds possible along parts of the coast.
Source: Men's Journal, reporting NOAA Climate Prediction Center outlook (Nov. 4, 2026)
For the November 12–15 window, the CPC also sees a moderate risk of heavy snow at high elevations in the Klamath and Sierra Nevada mountains and of high winds along the coasts of Washington, Oregon and much of California, and it says flooding is possible in parts of the Pacific Northwest and northern California. In areas burned by wildfires, heavy rain could cause localised flooding, the CPC said. The outlook's slight-risk areas stretch farther still: through Wednesday, November 18, a slight risk of heavy precipitation covers the entire West Coast and parts of the Desert Southwest, the Great Basin and the Southern Rockies, with a slight risk of high winds across much of the West Coast and the Interior West.
Source: Men's Journal, reporting NOAA Climate Prediction Center outlook (Nov. 4, 2026)
Background: a dry October meets the rainy season
The timing matters because the region is starting dry. Despite the incoming storms, Seattle experienced its seventh-driest October on record with just 1.2 inches of rain for the month, FOX Weather reported, calling the wet weather a welcome change for the dry landscape. November is normally the heart of the Northwest's rainy season, when Pacific systems arrive in sequence rather than singly — which is exactly the pattern both forecasts describe: not one storm with a name and an end, but a parade, in FOX Weather's phrase, in which each system tops up rivers, soils and mountain snowpack before the next arrives.
Source: FOX Weather (Nov. 4, 2026, 3:25 p.m. EST)
What it means on the roads — for truckers and the I-5 corridor
For Washington's large Punjabi diaspora — concentrated in the Seattle–Tacoma area and along the Interstate 5 corridor, with many readers driving trucks on I-5 and across the Cascade passes — the practical exposure in this forecast is threefold, and each part traces to a number above: heavy lowland rain (1–2 inches in the metro corridor, more on the Olympic Peninsula) raises the familiar risks of standing water and localised flooding on low-lying road sections; gusty coastal and lowland winds are the hazard the CPC flags for the coast in the second window; and up to 6 inches of snow at higher Cascade elevations is a pass-level issue, not a city-level one — drivers crossing the Cascades should expect conditions to differ sharply between the lowlands and the passes on the same trip. Those are planning implications of the published forecasts, not new warnings: the authoritative, hour-by-hour source remains the National Weather Service and Washington State DOT pass reports, and readers should check them before a crossing rather than relying on any weekly outlook, including this one.
Source: FOX Weather (Nov. 4, 2026, 3:25 p.m. EST)
What the forecasts do not say
Neither source names a specific river flood level, a specific pass closure, or a specific wind gust figure for Washington, and this article does not invent any. The CPC has released no totals for the November 12–15 event, models are still shifting day to day, and a moderate risk is a statement about probability over four days — not a promise that any given town floods. What is solid is narrower: two independent forecast products issued on November 4 agree that the Northwest turns wet from Thursday, stays wet through the weekend, and may turn wetter still in the middle of next week.
Source: Men's Journal, reporting NOAA Climate Prediction Center outlook (Nov. 4, 2026)
What happens next
The first marker is Thursday's low-pressure development in the Gulf of Alaska and the start of the rain; the second is how much of the Olympic Peninsula's up-to-5-inch forecast verifies by Sunday; the third is the CPC's next hazards outlook, which will either firm up or downgrade the November 12–15 moderate risk as the models converge. Seattle-area readers coming off a 1.2-inch October should treat this week as the season turning, not as a single storm to wait out — and anyone with travel over the Cascades or along the coast in either window should build the forecast checks into the trip, because in a parade of storms the second system, not the first, is usually the one that finds the ground already soaked.