I opened windy.com for the California area and I found that the California current is displayed in the opposite way - from south to north. Is it affected by the recent cyclone or am I misunderstanding windy.com?

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I'm certainly no oceanographer, but my initial thoughts were that most currents likely both vary and meander a lot. And I'd expect much like the semi-permanent atmospheric pressure systems, apart from the very strongest currents, the transport is a longterm average rather than a near certainty at any instance.

Seeing your run of questions on currents on Windy, I am a little interested what product Windy is showing.. whether it's surface ocean currents or maxima or mean or what. I couldn't find any information on that. Certainly wind will alter surface water flow, so I'd expect if Windy shows that it would be particularly prone to changes. And even at a bit of depth, wind can drive quite a few currents. Since wind is far from static in direction, such currents also wouldn't tend to be. And strong cyclones are far from atypical on the US Pacific coast, particularly this time of year.

But a quick Googling of the current off the west coast shows the change is more defined and typical:

enter image description here

That's from the California Current Wikipedia page. Digging in further, the Davidson Current is

a coastal countercurrent of the Pacific Ocean running north along the western coast of the United States from Baja California, Mexico to northern Oregon, ending at about latitude 48°N

... it flows north rather than south and hugs the coastline. The current is active year-round at 650 feet (200 meters) below sea level, but surfaces during the winter months, generally from mid-November through mid-February. In these months, northerly winds weaken and are replaced to some extent by southwesterly winds.

(note also that in your image, the flow still mainly has a small north-to-south component hundreds of miles offshore, which would tend to match the diagram)

Finally, tying it all together, it looks like the paper Buoyancy-Driven Coastal Currents off Oregon during Fall and Winter (Mazzini et al, 2014) suggests that the winter south-to-north near-shore current may in part be caused by the increase in amount/scope of river discharges that are typically greater in the winter there (due to the increased precipitation). Such that, while the water being discharged is colder than the ocean it flows into, its density difference (being freshwater) can cause it to flow north.

If that's true, an exceptionally rainy winter along the US Pacific Coast should indeed mean a stronger northward winter current.

But it looks like some degree of northward current right near the coast is quite common in the winter, so this appears to be normal.


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