- Accuracy seems at least somewhat correct.That wedge shape you see in the late afternoon sailors call "the wind engine". Local sailing magazine Lattitude 38 has a special PDF that talks about doing a sailing trip around the bay accounting for this local wind phenomenon.
Correct stuff:
- The SF waterfront, out to the edge of the piers is mostly calm which is correct
- Berkely, Oakland, Emeryville getting blasted late afternoon is correct
- Back side of treasure island, immediately to the east is much lower than the west side, particularly near clipper cove
- Vast majority of alameda estuary is dead calm, that's correct for this time of year
- There's a big blast of wind between Daly City and OAK international where there's a gap in the mountains
Weird stuff:
- Most noticable, is the wind is still strong up to and south of the bay bridge. The bay bridge has been described by many as "a wall" when it comes to the wind. There's a drop off but it's not in line with the bay bridge. At all. at least 45 degrees off from true wind speed.
- There's a very windy patch between golden gate coast guard station and belvedere, it's usually really patchy wind here but I guess if the wind direction is just right it'll blow there
- Pointe Bonita (lighthouse on the west side of gg bridge about 2 miles, north coast) they are modeling the gap in the rocks there and you can see it funnel through which is neat
It's a cool visualization though, gives you a great idea of where the wind is, and more importantly where it won't be. There are a bunch of races that start in the bay and head south towards Santa Cruz and Monterey so it's nice to better visualize where the wind just dies off on the coast as it skips over the mountains.
Anyone who wants to see what the wind is like in the bay I recommend reaching out to YRA.org they can put you in touch with a boat who needs crew most likely. There are races 4-5 days a week through november all around the bay.
It is modeling a distinct drop off of wind speed on the south side of the bay
Also, as a person with experience sailing on the Bay, this model immediately seems unusually accurate. It shows, for example, the Angel Island wind shadow moving around correctly as it does during the day, which I have never seen in another model.
Could anyone with more understanding of meteorology (or OP) please explain what is different about this model vs say the ECMWF model that you can see in apps like Windy, that are supposedly great, but just don't seem to get these features right? Those models are incredibly bad when dealing with the unusual local geographic features on the bay. What resolution are they operating at?
Thanks for the feedback :) The highest resolution models you can currently find on windy is around 3x3 km (HRRR) and this resolution is unfortunately too big to capture fine terrain and water features. 300x300 gives you 100 times more data points to work with.
How often are you planning to re-run this model? Can I convince you to rerun it before this weekend? I'm in a situation to get you a lot of new followers/users if I had a new model for Sat/Sun.
It's purely spatial resolution and the representation of topography that high-resolution simulation permits. Any NWP model like WRF or WRF-LES will produce topographic-driven wind fields with high fidelity pretty much out of the box, without any customization required. The result may be pretty, but it's really nothing of note from a weather modeling perspective.
ECMWF's model is 9km spatial resolution, so Angel Island probably doesn't even show up in the model domain.
- Accuracy seems at least somewhat correct.That wedge shape you see in the late afternoon sailors call "the wind engine". Local sailing magazine Lattitude 38 has a special PDF that talks about doing a sailing trip around the bay accounting for this local wind phenomenon.
Correct stuff:
- The SF waterfront, out to the edge of the piers is mostly calm which is correct
- Berkely, Oakland, Emeryville getting blasted late afternoon is correct
- Back side of treasure island, immediately to the east is much lower than the west side, particularly near clipper cove
- Vast majority of alameda estuary is dead calm, that's correct for this time of year
- There's a big blast of wind between Daly City and OAK international where there's a gap in the mountains
Weird stuff:
- Most noticable, is the wind is still strong up to and south of the bay bridge. The bay bridge has been described by many as "a wall" when it comes to the wind. There's a drop off but it's not in line with the bay bridge. At all. at least 45 degrees off from true wind speed.
- There's a very windy patch between golden gate coast guard station and belvedere, it's usually really patchy wind here but I guess if the wind direction is just right it'll blow there
- Pointe Bonita (lighthouse on the west side of gg bridge about 2 miles, north coast) they are modeling the gap in the rocks there and you can see it funnel through which is neat
It's a cool visualization though, gives you a great idea of where the wind is, and more importantly where it won't be. There are a bunch of races that start in the bay and head south towards Santa Cruz and Monterey so it's nice to better visualize where the wind just dies off on the coast as it skips over the mountains.
Anyone who wants to see what the wind is like in the bay I recommend reaching out to YRA.org they can put you in touch with a boat who needs crew most likely. There are races 4-5 days a week through november all around the bay. It is modeling a distinct drop off of wind speed on the south side of the bay