Eddie: A legendary Southern California sportfishing boat skipper, long associated with the Pacific Queen.
Eddy: A current of air or water, running contrary to the main current, especially one having a rotary or whirling motion.
Catalina Eddy: A circulation that forms over the coastal waters of southern California, most common in the spring and summer months and is associated with a deepening of the marine layer.
The typical setup for May and June in the eastern Pacific features a strengthening area of high pressure, centered 500-1000 miles off the California coast.
The wind circulation around this “Pacific High” is the driving force behind our nearly persistent northwesterly wind offshore, resulting in the localized weather phenomenon known as the Catalina Eddy.
As the steady wind passes down the Central California coast, a swirl forms downwind of Point Conception, often in the vicinity of Catalina Island, hence the name Catalina Eddy.
That swirling vortex reverses the wind direction along the coast inside the Southern California bight, deepening the overcast we refer to as the marine layer and often pushing those clouds well inland during the nighttime and early morning hours.
Here is an example of a small-scale eddy circulation in a visible satellite image of Southern California: