So Cal Wind Patterns

[Bepi]

Is it me or has the west wind taken a long holiday? I cannot remember a longer period of light winds that box the compass.

 

[Pete the Cat]

Something is up with the winds here in SF Bay. I have been sailing here for 50 years and things have been getting different in the last years. More winds from odd directions--fewer from "prevailing" directions. More turbulence and wind shear where the wind will be 7 knots from one direction and then 17 for 5 seconds from another. As a pilot, I am familiar with wind shear we experience on approaches to landing--and this, too, seems to have been increasing in the last decade. I am not sure what is actually causing all this--but it seems our patterns are disrupted or evolving.

 

[Christian Williams]

Bepi, it seems to me just a typical influence of the Santa Anas--our winter desert winds from the northeast.

The winds howl down the canyons at 50 mph, warming on the downslope side, but by the time they get to the shoreline they peter out, leaving a rippled lake surface.

Sometimes as the Santa Anas weaken they battle the natural afternoon sea breeze, leaving a dead zone a mile wide off the surf.

If anchored near a steep shore, a Santa Ana can imitate a Patagonian williwaw in intensity, whereas a few miles offshore it is calm.

We have weird weather here, compared to other places I've lived. Nonweather, I call it, because it is localized with no fronts involved. Non of my eastern prediction rules seem to apply. In summer the hot valley draws sea air inland, building during the day, such that the coast is blanketed in fog at 65F, whereas 10 miles east. on the other side of the coastal range, it is 110F.

Such a marine layer kills Hurricane Gulch, the normally reliable windsurfing spot in San Pedro. I mean "San Peedro."

But generally we have light winds in winter, like everybody else, unless a front passes. Summer is a predictable 15 knots max, with a shift from southeast in the morning to southwest by lunch.

I am finally used to it.

 

[paul culver]

Brian Fagan has a chapter on weather in his book "The Cruising Guide to Central and Southern California". As I recall he points to the location of the Pacific High, which is always in flux, as the dominant force in our coastal weather.

 

[Bepi]

Bepi, it seems to me just a typical influence of the Santa Anas--our winter desert winds from the northeast.

The winds howl down the canyons at 50 mph, warming on the downslope side, but by the time they get to the shoreline they peter out, leaving a rippled lake surface.

Sometimes as the Santa Anas weaken they battle the natural afternoon sea breeze, leaving a dead zone a mile wide off the surf.

If anchored near a steep shore, a Santa Ana can imitate a Patagonian williwaw in intensity, whereas a few miles offshore it is calm.

We have weird weather here, compared to other places I've lived. Nonweather, I call it, because it is localized with no fronts involved. Non of my eastern prediction rules seem to apply. In summer the hot valley draws sea air inland, building during the day, such that the coast is blanketed in fog at 65F, whereas 10 miles east. on the other side of the coastal range, it is 110F.

Such a marine layer kills Hurricane Gulch, the normally reliable windsurfing spot in San Pedro. I mean "San Peedro."

But generally we have light winds in winter, like everybody else, unless a front passes. Summer is a predictable 15 knots max, with a shift from southeast in the morning to southwest by lunch.

I am finally used to it.

I don't think it's any cataclysm but it is definitely unusual. I have spent most of my life outside here in southern california from living at the beach with my friends to working for the family construction business to rowing a gondola for twenty years and then my three short years of sailing experience. Having plowed through high winds during countless days and nights rowing a 36 foot flat bottom vessel with a 13 foot oar I kid myself that I am attuned to the weather. I'm sure all will return to normal after the equinox, but i've been looking for winds that will let me sail to catalina and I have not seen anything decent for months. I could motor over but I never feel comfortable with only one form of propulsion available. Anywho... i'm sure all will be well. Though there is that pesky fact that the three gorges damn in china measurably moved the rotation of the earth. .Only 000001% Or so...
But that is a pretty big butterfly.... I'm not saying that the dam has changed anything... but as a natural philosopher I love asking questions.