voodoo winds at stinson

[churan]

Mike,

Can you back cast todays wind at Stinson beach? I arrived 2ish dead calm. An hour later was almost leaving and it was starting to blow NW through tomales gap. Put up a 12 since it had been dead calm. By the time I was on the water it felt solid 20 perhaps more, NW. On the water I was completely overpowered it was blowing sheets of sand 20' in the air on the beach. Not good. I had friends land my kite or I was in deep trouble. The wind was nuking through town blowing dirt, leaves etc. no locals had ever seen anything like it. I stopped at the bluff at HWY1 south of town. see pic. and it was calm again. Then it started nuking from the South. So within 3 hours it went calm 30 nw, 30 east, and 30 south. Glad I am not in the news. Was it an eddy on steroids? went from hot to cold to hot too.
Thanks,
Jeff

[windfind]

Hi Churan,

Wild photography! Having lived and surfed at both Stinson and Bolinas I can also attest that I have not seen conditions like that.

I am working on a blog about yesterday's Bay Area winds. Below is a very rough draft of the some of the imagery I will use in the blog.

Notice how many sites had winds that shift all around the compass and were extremely up and down or even on and off.

Here is a sampling of some of the words I used in my Saturday 7AM forecast to describe what I expected: Bizarre, Wind could die fast, Variable winds (3X) UP AND DOWN (5X), weather picture is a mess today, rest of the Bay Area will be iffy, clouds from Linda may shut down the Bakersfield pressure gradient, Peninsula winds iffy, Fog permitting: (4X).

I guess I was trying to convey that things would be really weird but light at most sites but I stressed that there were powerful 40-50 knot gusts just aloft but I did not expect them to hit the surface at sites inside the Bay.

NOT forecasting dangerous gusts inside the Bay was a very tough decision since just a few days ago I put out a "dangerous for kite launching" warning and a fellow waterman died that afternoon. So not forecasting dangerous conditions with 50 knot gusts overhead had me sweating bullets yesterday. Looking at the orange Bodega profiler data you can see the blob of powerful NW wind just aloft yesterday.

It turns out I made the right decision except as you point out, for Stinson.

So why the weird and crazy wind at Stinson? First look below at the wind map of the Bay Area and find Stinson. Notice that Mt. Tam, near Stinson, had gusts to 50 knots while some East Bay hills had gusts over 40 knots.

Since the air in these gust were composed of unstable air I felt they just would weaken the surface wind but I did not expect them to reach the surface except at Sherman where I knew they would make the wind UP AND DOWN.

Now look at the bottom satellite image. See what looks like an explosion SW of the Bay Area? This is from a Cut-Off Low at ≈ 18,000 ft. that was jazzed up by moisture from former Hurricane Linda. For most of the Bay Area the winds from the Cut-Off Low just interfered with and weakened the surface wind.

But as Stinson locals know there massive wall like coast range ridge right behind the beach. Looking at the green arrows near Stinson you can see that as this above surface wind hit that ridge at right angles it could either turn NW or SW. As it switched from NW to SW it stirred the surface winds as you experienced and documented in your photos. Does this make sense?

Can I have your permission to use your photo and text in my blog?

This is an extremely rare event but I will try to watch out for in the future so I can post a Stinson warning.

Mike Godsey
iwindsurf.com/ikitesurf.com
Weatheflow.com

[churan]

Thanks Mike,
To be clear, it was a wonderful weather event and each waterman must be responsible for their decision. I would never blame a forecast. Recent events were on my mind when I sought help to safely end my session. Thanks for the info explaining what was an epic afternoon to witness. Next time I will pack my sailing gear as well, imagine side off port and starboard in the same session. Nuts.

[nw30]

Kind of similar, but with lighter wind~
Back in the mid 80's some friends of mine and I went camping at Zaca Lake, it's up in the Santa Ynez Mts. behind MJ's Neverland ranch. It's a small round lake up near the summit in round canyon. Because I was taking my van which had my WS'ing gear in it, I decided to leave the gear in there, after all it's a lake, and who knows.
The wind was very light, but there was wind, with nobody on the lake and no other WS'ing gear anywhere, I may have been the first to even consider sailing there. I rig, I launch, and the wind took me slowly along the shore line, and along the shore line, and along the shore line, and along the shore line. I circumnavigated the entire lake w/o having to make a single jibe or tack, always on one side of the sail only. I went around the lake about 3 or 4 times then quit, that was weird.
Funny thing, about 2000' straight above me were several gliders circling in a vortex to gain altitude, gliders are popular there at the Santa Ynez airstrip. The rising heat from that round canyon was obviously making the vortex, but it must have reached all the way down to the surface of the lake as well,,,,,,,, I think. \__/
Anyway never done that before, or since, and I've never been back.

[scameron]

On Sat, I brought my sailboat up the coast from Santa Cruz.. Besides the open ocean being extremely bumpy, I got my ass handed to me! I got clobbered by a squall while I was off Pacifica. The breeze then shifted 189 degrees, waves built fron the opposite direction, and 2 hrs later the whole process started up again! I got to my marina with 30 kts of sw. Crazy day!

[scameron]

On Sat, I brought my sailboat up the coast from Santa Cruz.. Besides the open ocean being extremely bumpy, I got my ass handed to me! I got clobbered by a squall while I was off Pacifica. The breeze then shifted 189 degrees, waves built fron the opposite direction, and 2 hrs later the whole process started up again! I got to my marina with 30 kts of sw. Crazy day!

[windfind]

[dsgrntlxmply]

It is reported that a group of 54 kayakers were rescued from Tomales Bay Saturday night after encountering sudden intense wind around 10PM.

They were on a nighttime excursion to look at bioluminescence.

I was at Bodega Bay Saturday afternoon. The weather was chaotic, with strange clouds, fog coming and going, and sudden changes in wind speed and direction.

I made a choice not to sail, because the water was reading less favorably than the anemometer was indicating, and there was not much time left before the depth ebbed to too shallow.

The Bodega profiler image from Saturday is very interesting.