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A 220 mph jet stream sets up a stormy week for the West Coast

By Ryan Hall, Y'all Weather Desk · Published November 9, 2026, 3:03 PM ET

Written by our automated news desk from National Weather Service data.

A jet stream blowing about 220 mph six miles up pushed a 747 to 789 mph over the Pacific, and it is aimed at the Pacific Northwest and Northern California this week. Expect repeated rounds of coastal rain and mountain snow, with a stronger push late in the weekend. Coastal flood advisories and beach hazard statements are already up along parts of the California coast.

A river of fast wind about six miles up is aimed straight at the Pacific Northwest and Northern California, and it will keep sending storms ashore all week. Expect rain along the coast and snow in the mountains from the Cascades to the Sierra, with a stronger push possible Sunday into Monday. How strong the jet gets is still being sorted out, but it is not letting up.

Why a 747 hit 789 mph

Ryan's new Short started with a plane. At 4:04 PM ET Saturday, a Korean Air 747 flying Seoul to Los Angeles showed a ground speed of 789 mph over the North Pacific. Another flight was at 761 mph. These jets normally cruise around 560 mph, and nothing was wrong with them.

They were riding a tailwind. About six miles up, the jet stream was blowing roughly 220 mph, right under the fastest plane. Flights heading back to Asia were crawling along near 500 mph. They fly farther north, out of the worst of it.

That same jet is what steers storms. Think of it as a conveyor belt carrying systems to the coast. This one is pointed at the West Coast.

Rain on the coast, snow in the mountains

Steady Pacific moisture heads for the Pacific Northwest and Northern California all week. Several quick disturbances ride in Thursday into Friday. That means periods of snow in the Washington Cascades and Olympics, plus the mountains of northern Idaho and western Montana. Our winter storm outlook has a risk area near Bellingham for that stretch.

The bigger change comes Sunday into Monday. A stronger system and cold front push inland with a wider, heavier shield of precipitation. Snow levels fall across the Cascades and the northern Rockies ranges. Our outlook has a risk area for the Spokane and Tri-Cities part of eastern Washington by then.

Confidence is split. The models agree the active pattern continues. They still disagree on how strong the jet gets, so the rain and snow totals for the weekend system are not locked in. Check our snow forecasts as the week goes on.

Surf and coastal flooding are already a problem

Some of this is happening today. Along parts of the Pacific Coast, including San Francisco, breaking waves of 12 to 16 feet are bringing a higher risk of sneaker waves and strong rip currents through Monday evening. Low-lying shoreline spots around San Francisco Bay and San Pablo Bay could see up to 1.6 feet of water over the ground. That advisory runs until 4 PM Pacific Friday.

Farther south, Los Angeles and Orange County beaches, the Malibu Coast and San Diego County have coastal flood advisories until noon Pacific Tuesday. Expect minor to locally moderate flooding at morning high tide. Surf runs 4 to 6 feet in the Los Angeles area and 3 to 7 feet in San Diego County, especially on west-facing beaches. Every active alert is on our warnings page.

Elsewhere in the lower 48

Texas gets the only flash flood risk today. It is Level 2 of 4 (Slight Risk) for far southeastern Texas, where soils are already soaked. Tuesday looks quiet nationwide for severe storms and flash flooding.

Wednesday has a Level 1 of 5 (Marginal Risk) for isolated damaging wind gusts. It covers parts of Tennessee, Kentucky, Illinois, Indiana, Missouri and Arkansas, including the Clarksville, Evansville and Cape Girardeau areas. That system then brings wet snow to higher terrain in West Virginia and western Pennsylvania late in the week.

What to do

• Beaches in California: Stay off jetties and keep well back from the waterline through Tuesday. Never turn your back on the surf.
• Low-lying shoreline areas around San Francisco Bay: Move cars from the lowest spots at high tide through Friday.
• Mountain travel in the Cascades and northern Rockies: Check pass conditions before you go Thursday and Friday, and again next weekend. Carry chains and extra supplies.
• Everyone on the West Coast: Check back daily. The strength of the weekend system is still uncertain, and Y'all Alerts can ping you when warnings go up.

Bottom line

A jet stream fast enough to push a 747 to 789 mph is lined up on the West Coast, so plan on a wet, snowy week there. The pattern is locked in, but the details of the weekend storm are not.

Explained: Flood Advisory, Watch, Warning and Flash Flood Warning explained

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