CATALINA CROSSING TOO!!!!!!

[William Novotny]

Originally Posted by Fiskadoro

Not fall so much as Winter, I think it's best before a Santa Ana event where you have a weak high pressure system over the Mojave that's not strong enough to generate a Santa Ana but strong enough to stop any onshore winds.

I'm not a meteorologist but the deal is that when the desert warms the warm air rises and the resulting low surface pressure pulls in cooler denser air off the ocean which passes over us at the coast. In the early fall we have a slightly cooler air temperature on the coast, but the desert is still warm and offshore outside the islands the water and air get colder faster do to the cold California Current. The greater the temperature difference between the desert and offshore the more intense the displacement effect. So when the desert warms up in the fall the effect is intensified due to the colder temps offshore.

Catalina Channel acts like a funnel, channeling the air (wind) coming in from offshore increasing it's speed as it comes down the channel. Though I'm not sure how all the variables work sometimes cold air from offshore rushes through the channel displacing warmer air on the coast, and it can become a sustained longer pattern.

I know that September October it can get really bad much worse then I've seen it in the Summer. The winds can be more intense and last longer. It's almost like a mini cold front the cold air comes in from offshore and then continues to blow for a extended period. If I had to guess I would say the offshore air is cold enough it continues to displace the warmer desert air even at night after the sun goes down and the thermals stop, but it only seems to happen in the fall.

In the winter the temps are more balanced because the California Current does not get that much colder, so the sea and land temperatures get more similar and things get balanced out. Then when you then get a weak high pressure system in the desert (like before a Santa Ana) it blocks the cold air from coming in from offshore, creating a extended period with no wind. Too much pressure and you get the reverse winds or Santa Anas, but with the right amount of high pressure you get an extended calm. Supposedly those no wind periods are the ideal times to paddle across but they only happen during the winter not the summer.

At least that's how I think it works.

Jim

Thanks for this info, I learned quite a bit from this post and it really puts things into perspective as far as event planning for an endeavor like this and what to be mindful of.