I don't know about other coastal areas, but the winds in SoCal will frequently blow either from the water or to the water due to other meteorological factors: https://en.wikipedia.org/wiki/Santa_Ana_winds
I don't have hard data to back this up, but a number of my coworkers including a weekend sailor all feel that the general coastal climate and wind patterns have changed compared to what we remember from 20 years ago.
There seems to be much less of the strongly seasonal offshore flow (the Santa Ana winds) reaching us at the coast. This used to be a regular thing ramping up in the late summer and fall with huge wind gusts damaging local trees etc. Now, it seems like we hear about winds up in the mountains but they run out of energy (or lift above the surface?) before reaching the coast, while we can definitely feel the grit and see the brown, dirty layer of air extend out over the ocean.
Similarly, we have all commented on the disturbance in the strongly seasonal pattern of onshore flow (June Gloom). We remember more contrast between foggy mornings with the marine layer reaching many miles inland on some mornings but retreating and burning off, tending to blue skies in mid summer. In recent years, the marine layer seems to visit randomly throughout the year and it often seems to just park slightly off shore or mere blocks inland, with haze and humidity instead of sharp boundary between blue sky and fog.
In our coastal area between LAX and Santa Monica, we haven't had the obvious wildfire smoke impact that I saw during visits to the S.F. Bay Area this year.
I live on the Central Coast and it never struck me as very windy around here, at least compared to other places I've been. I looked it up and as I thought, the winds are further North:
> It blows the most in the dead of night, precisely when there’s the least demand for electricity. That’s true for just about every wind-blown spot across the U.S., from the foothills of the Tehachapi Mountains in California to the coastal plains of North Carolina.
I live in Northern California (SF). Winds don't start until about 1pm or so. And it's almost never windy after 8pm.
I think this pattern holds for most coastal places, because as the sun reaches the peak, it heats up land, forcing the air over the land to rise; but the water doesn't heat up as much, and hence winds come in from offshore, to replace the air rising above the land.
Actually deserts can be quite windy, especially deserts near the ocean. Wind forms when there's a pressure differential, and the most common reason for a large pressure differential is when there are two adjacent areas with a significantly different temperature. So when you have a desert next to the ocean, the desert cools at night and then during the day, as the air in the desert heats up, it lowers the air pressure on land and pulls in air from the cooler air over the ocean. This phenomenon is why the SF Bay Area consistently has high wind and good sailing conditions during the summer, especially in the afternoons.
That said, none of this contradicts the overall point you were making.
Off shore you get 24 hour constant wind, the synoptic wind. When we race to Hawaii, first you HAVE to get past the Farallones the first day and into the synoptic wind. If the inshore wind shuts down, you're bobbing all night with 0 wind. Get to the synoptic wind, set the spinnaker and it's a downhill sled race to Oahu.
At the coast, you get marine layer driven winds in the afternoon, dying off in the evening. Stockton heats up midday, creates a low pressure and sucks in the marine layer. It cools off in the evening, shutting it down.
Now, as to the wind chart, that's CA as a whole. Dunno. But wind is definitely not random by geography and season. Basically, it's solar driven.
It gets plenty windy just a few miles out into the Pacific Ocean. Pay attention to the marine forecast for a few months and notice how often they include small craft advisories.
Most of the wind is 4-12 miles offshore, as the wind rolls down the coast it's blocked by the mountains that run along the coast. At 25 miless offshore you get into mesoscale wind patterns which are extremely stable and aren't impacted nearly as much by day/night cycle, and can be forecasted with great reliability days and sometimes weeks in advance, particularly in the summer once the north pacific high settles in between CA and HI.
I'm not seeing much of a wind shadow for that bridge, particularly at 4pm Friday. Maybe they updated the model already. Most of the onshore windflow begins after 11am goes from the cold (high pressure) pacific through the gg bridge, wraps around the east side of angel island and north past Richmond and Vallejo towards the hot (low pressure) central valley. South of SFO silicon valley is surrounded by tall geographic features and there's not much path to hotter (low pressure) zones so it's unusual to see high winds there unless there's a special offshore wind event coming from the south (most often in the winter).
I see that you didn't mention tailwinds. Because, of course, they're a myth and don't actually exist.
I recall reading the meteorological explanation for why the wind changes direction on ocean cities. The net effect for me is that I'm nearly always going into a local headwind and it's quite horrible.
The wind appears to be significantly stronger over open water. Is this just an artefact of the visualisation, or is it a genuine meteorological phenomenon?
I understand the temperature differences between sea and land will make it windier around coastal areas, but I had always thought that was a localised effect.
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