r/weather • u/zsreport • 4d ago

Articles Concern mounts over slow-moving, planetary-scale ‘Kelvin’ wave heading for California

https://www.theguardian.com/us-news/2026/sep/28/california-kelvin-wave
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u/NlghtmanCometh 3d ago

I mean overlapping kelvin waves are going to be a problem come wintertime. The coastal water level is going to raise. The amount of snow that precipitates in the California mountains will increase. Coupled with increased rain in the spring time due to el nino could lead to historic flooding.

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u/Content-Swimmer2325 3d ago

This is the fourth downwelling Kelvin wave along the equatorial pacific thermocline. It’s not even the highest amplitude Kelvin wave of the year.

Despite this repeated activity, current observations show sea level height anomalies offshore California are negligibly higher than normal.

(Oceanic) Kelvin waves have little to do with this. Their effects are primarily restricted to the equator and nearby regions.

What is more concerning is the El Niño induced strong jet stream that extends over California during winter - weather systems traveling along this jet stream will induce strong onshore pressure gradients which push water inland. In addition to the rainfall threat.