The elusive future of San Francisco’s fog | Hacker News Reader

The elusive future of San Francisco’s fog

nytimes.com

152 pointsanyonecancode114 comments

One of the more memorable and surreal experiences I had on my visit to SF was walking around Golden Gate Park, and suddenly seeing what looked like the mast of an alien sailing ship looming out of the fog in the distance.

It turned out to be Sutro Tower.

Had you acquired chocolate bars from some hippies by any chance?

You know you can just go to a store for that now, and they’re not run or frequented by hippies.

Depends if it has mushroom in it

Fair enough

You'll be able to go to a store for that soon as well!

https://www.cnn.com/2022/09/10/us/san-francisco-decriminaliz...

It’s weird because everyone in SF has been saying that these have been decriminalized when the news says that nothing has happened yet AND it’s not about decriminalization:

> It calls for San Francisco police to give investigation and arrests related to use of such substances “the lowest priority.”

That recent law regarding mushrooms was political theater, sponsored by two of the most left-leaning supervisors on the Board of Supervisors[1] worried about potential challengers, especially since the Boudin recall, whom they aggressively supported. Everybody else went along because how could you vote against it?

Just like marijuana, SF police haven't cared about psychedelics for decades. And while there may have been occasional pretext arrests for drugs in the past, encounters were always initiated for something else, and in any event these days police are hesitant to stop in-progress, felony property and violent crimes occurring in front of their faces. I mean, we have open-air heroin markets, and even after Boudin's recall you have to be a distributor, not simply a street dealer, to even get the attention of authorities, police or the DA.

To be fair to progressives and liberals generally, those two supervisors are particularly contemptible, pandering politicians, Dean Preston especially. Hillary Ronin seems more sincere, if misguided, but Preston has no redeeming qualities as a politician.

[1] Which itself is obviously all Democratic, with most if not all members self-identifying as progressive.

It's generally good to encode these decisions in law rather than hand police even more discretion... but I 100% agree with you on Dean Preston and Hillary Ronin. They weaponize progressive language to preserve the status quo.

> It's generally good to encode these decisions in law rather than hand police even more discretion.

Agreed. But this falls short--it's a hack based on budget stipulations that seems to have become all too common; it doesn't really change the status quo given current and long-standing official city policy regarding drugs, especially wrt recreational and medicinal drugs. I'm not even sure it's even enforceable. The DA's office is independent, and I don't think this would prevent a cop from pretextual application of drug laws, which have usually been in violation of city policies, anyhow, such as a marijuana charge that local papers made hay out of recently, but which actually occurred several years ago, was clearly pretextual and against rules (the cop was a rookie), and was never even prosecuted--not even sure it was an actual charge, may have just been listed as probable cause for a search or detainment.

Is there something more that a local municipality can do when it's illegal at the state and national level? I'll admit I don't know anything here. It just struck me as more official than the existing wink and nod.

I suppose it varies. But DAs have wide discretion--strictly speaking, absolute discretion--to abstain from prosecution, and in San Francisco the DA is an elected position, which is common nationwide. (SF also has an elected public defender office, which is extremely rare.) Moreover, AFAIU DAs have some supervisory authority over the police, by law (e.g. investigating misconduct) but mostly by the fact that it behooves the police to have good relations with the DA (and vice-versa). So police aren't in the habit of enforcing specific laws or making arrests that the DA is unlikely to prosecute. And unlike many other cities, the SF DA's office is not very deferential to police department demands--e.g. how to expend their resources to best improve public safety in their opinion--which is often cited as a major reason for supposedly exceptionally low morale among SF police officers.

SF in particular also has a Police Commission, which has direct supervisory authority over the police department, including setting and enforcing policy. Four SF Police Commissioners are nominated by the Mayor, and three by the Board of Supervisors; all must be ratified by the Board of Supervisors. Usually a Police Chief, especially outside major cities, is the top such authority, though the SF Police Chief still has plenty of discretion, and is still appointed by and answers directly to the Mayor.

So in SF both the citizenry via the elected DA, and city politicians via their appointments, control policy regarding if, when, and how criminal laws are enforced. And those are the avenues by which SF has already circumscribed and muted drug laws otherwise beyond the city's control. So the mechanisms are in place, not to mention the actual policies; thus why I called the bill theater. Strictly speaking, though, it has some substance in the sense that it prevents the DA, Police Commission, Mayor, or Police Chief from rolling back existing enforcement restrictions, to the extent they could do so independently.

You can find that too at zide door

Not in sf tho :P

I was curious what that looked like and turns out there are videos on youtube: https://www.youtube.com/watch?v=60fqruVDrjs

Pretty cool!

Another cool video of going to the top of the tower: https://www.youtube.com/watch?v=7JPJ4oZDY7I

> The general consensus among the small cadre of scientists who study coastal fog is that it is decreasing, not just in California, but around the world.

It’s true. The last time I saw thick fog in the city, the kind where you almost had to pull your car over because there was a chance you might hit another car, was 1989.

Fogust seemed to be getting lighter when I was living there as well. Anecdotal but noticeable.

we would get it in the Richmond. The thickest fog in the bay area right I know if is always around Skyline between Westmoore and Hickey - it still gets that thick there.

You should visit Daly City; Skyline (35) still gets shrouded in fog fairly often.

Also, if you miss the fog, both Skyline and US-1 in that part of the world are absolutely gorgeous.

I had a nice view from UCSF 1995-2001. Fog came in full and thick nearly every day. When I drive from San Mateo to South SF I frequently see a large offshore flow causing massive fog at Mt San Bruno. Any possibility your data is mainly anecdotal?

Concur: I spent perhaps 10 days in the city in 1995 split into two blocks at end of June and beginning of September. Definitely foggy on multiple days, especially over towards Golden Gate Park and the bridge.

If we're going by anecdotes... when I came to this city I was told thick blinding fog is a daily occurrence, but I was here a good week or two before the "real" fog came in, and while fog does come often, that honestly doesn't come often. Maybe 3 times a week.

I classify "real" fog as days where I go from being able to see half of SF and even a bit of Alameda... to not seeing the houses a block down from my balcony.

I'll admit it's impressive and straight up disorienting sometimes, (looking out at what was a skyline 20 minutes before and seeing nothing but grey), but if the locals' anecdotes about how often it used to happen are even somewhat accurate, it sounds like it's on the decline.

It's not daily- there is more like a cycle caused by changes in offshore flow and temps in the inland valleys. I'd see a week without any fog, then a two weeks of in-and-out fog, then a week of total fog, including times when I couldn't see more than a few avenues towards sunset, or the park looked like some misty dream.

This must depend on where you live in the city – just yesterday we had massive fog in the morning and at night in the sunset.

While the sunset is foggier than the rest of the city I can confirm nothing in the past few days comes even close to what used to be considered "dense fog" for SF. I remember walking in fog like that and not hearing even fairly loud cars till they were almost right on top of me because of how noise-dampening the fog was.

We still get haar a lot here in Scotland - its very common on the Firth of Forth:

https://en.wikipedia.org/wiki/Haar_(fog)

Edit: I have no idea whether haar occurs more or less frequently - I moved to a spot where it is very visible a few years back so it certainly looks more common to me!

Happened last year in Ingleside Terraces. Could barely see the curb.

I heard most of the city used to be very foggy for months on end. But now most of the city is sunny all year round before noon till early afternoon (about 11am-3pm) except maybe parts of outer sunset and outer richmond. In Bayview, fog doesn't even usually roll in until after 10pm (except in July)

This is true. I've lived in the Bay Area since '05, and have met many people who were there since the 80's and 90's. Actually, I think most of them have left. But by the mid 2010's, many of them would comment on how unusual it was that the fog just wasn't rolling in anymore.

One person I knew was sensitive to certain allergies that would become markedly worse without the fog. So she knew.

It isn't just SF proper. Along the peninsula, on Highway 35, the fog used to be so thick you couldn't see more than 30 ft in front of you – maybe even 10 ft some days, and especially in the evening. I lived in those mountains around the 2006-2007 timeframe, and it was fun to drive down the 35 by memory (at least if you were an indestructible-feeling 20-something), since it wasn't possible to see down the road for any safe distance. Nowadays, there might be fog, but it's invariably "safe."

Another bit of history. The first navigators kept passing by the bay for years because they could not see the bay from the sea due to the fog. This is why people settled in SF later than in other places in the region. So, the fog was probably damn thick at the time.

And from what I remember Skyline drive was the original way to go north and south on the peninsula (dirt road)

No telling stories about how great the Lucky Penny was.

> And from what I remember Skyline drive was the original way to go north and south on the peninsula (dirt road)

PTSD, activated! I had a sadist as a DMV driving instructor who forced me to take my test on that road.

When I hear people complain about the weather in SF now I always think "if only you knew...."

I lived in SF from 1989 to 2006. In the summer, downtown was usually sunny during the day while sunset and richmond were socked in. Fog moved further in towards the afternoon/evening. I lived in the sunset and richmond the whole time and didn't see any change. In 1989 I sometimes didn't see the sun for weeks and 2006 still didn't see the sun for weeks, in those districts. Maybe something has changed in the last 15 years?

One of the guesses in the article was less pollution to form smog eith. That feels right to me.

One of my most magical bike rides was along Skyline Boulevard on the coast range on the SF Peninsula. It was a summer day as the fog moved in; there was a moderate wind out of the west, pushing clouds from west to east.

In the less densely-forested areas, it was windy and cold, but every time we went through a patch of trees, the wind died down, and it was raining. The way the trees caught the blowing fog meant it was more than the drips you get off of trees some days, but it felt like actual, natural rain. And I imagine on some level it's difficult to truly parse out the difference between which droplets came from fog hitting tree branches, and which were forced out of the cloud by the slowing and densifying moist air as it hit a thick grove of trees.

I realize this is pretty subjective, but there is not a single time that I have appreciated being in the fog on a bike ride or hike. It can be pretty to watch rolling in over the hills, but once I am in it, I always feel cold and miserable. I'd almost prefer that it just rain, because at least then I would have a valid excuse to stay home.

Different strokes. I feel most alive when Mother Nature is giving me spooky wicked weather.

Agree. Something primal about it I think.

It's been a few years, so my memory might be rosier than the experience was at the time. I grew up in the PNW and it was a solid 10 years in the Bay Area before I could actually appreciate rain again. And I still hate it when bad weather ruins my plans.

However, one of my favorite scenic things here on the Peninsula is watching the clouds/fog crash over the coast range every afternoon in the summer. From a safe distance in my 70 degree neighborhood, of course.

I had a similar experience biking on Mnt Tam. It was pretty amazing. I also recall it being pretty hot and sunny on the way up and the way down and it only being cold, foggy and wet at the very top. The contrast made even more magical.

Who knows, dense fog could be an artifact of the abnormally wet 20th century that California has seen, looking back 2000 years the typical state for California is very dry. Back 1200 years there were a few megadroughts that lasted centuries, here is an article that shows history of drought/rain in California, (on the infographic showing wet and dry periods) notice the huge peaks in the 20th century, and the steep drop in the 21st century.

https://www.nytimes.com/2015/04/14/science/californias-histo...

I assume this consistent fog is an function of higher latitudes with dry hot inlands and cool oceans. Especially in the desert, fog will form near the coast.

As SF Bay adds a lot of coast line, meaning more cool ocean closer to more hot land than most coastal cities, I'd imagine that has a large effect on why fog forms.

If ocean temps rise faster than average land temps, the average difference between them will shrink, perhaps bringing on average less fog?

Interesting reading: https://ggweather.com/sf/narrative.html

yes, but also look at the age of the trees in the coastal forest (or the age of the trees which didn't get cut down by us). Suggests that they might be a different "micro" climate; also note the earlier comments that they create fog.

Surprisingly deep article.

A little known fact is that the coastal forests exhale fog. You can watch them breath out drifts of cloudstuff at the right time of day and weather conditions.

They are releasing moisture, but also microscopic pollen that act as the nuclei of fog/cloud droplets and actually cause condensation.

The California Coastal Commission is more important than you might realize. Keeping the coastal forest intact and operational effectively "air-conditions" the whole state to the Sierras. The Central Valley would be an oven without the coastal forests.

Yes. Many of my favorite places in the PNW (so far) are the coastal forests and beaches in Mendocino County, around Eureka. A similar phenomenon can also be observed in the forests around Marin/Mill Valley. I always imagine Karl starting the trip from there.

The coastal forests in Northern California are beautiful. One geographical note: Eureka is in Humboldt County.

Ah thank you! It’s been a while since I made the trip.

Gotcha! I only know because I very recently made the trip.

I don’t think that’s considered the PNW, is it?

It's a debated thing. I consider the PNW to be a shared biome, and that area feels much more like the Oregon coastline than the rest of California -- distinct from Sonoma County-ish on south.

I feel I should amend that last paragraph: the coastal forest moderates the weather of the central and northern parts of the state. The southern part is an oven.

There's also the "fog 2.0" we're seeing now, which is really smoggy air which is visible because of the particulate matter from wildfires.

I'd say we see this type of "fog" more often than real fog in SF today.

I can't recall a single day this year during which we've had what you've described. Certainly the "more often than real fog" statement is completely false.

I'm not sure what we're disagreeing about here.

Do you doubt there's been smoggy air here in SF, which you can see due to particulate matter from the wildfires? This happens often. I mean it's basically just slightly thicker than normal smog. And there have been many fires. It's an unremarkable, common occurrence in the Bay Area today, this smog that is made worse by fires.

When it's moist out - not enough for real fog, mind you - it can pass for a fake fog.

Due to the heat, there's also been much less real fog.

So all I'm saying is that there have been more days w/visible smog than fog in SF in 2022. Which I stand by, as something I've observed, which is also something you'd expect, given 1) number of fires increasing smog and 2) heat wave decreasing real fog.

Correct, we've had a really mild wildfire season so far, Mosquito fire notwithstanding.

https://fire.airnow.gov has the map of the smoke plumes, locations of fires, and air quality sensors.

For a given sensor, you can pull up the hourly data for the past 7 days.

I once did a film about the fog and its fundamental importance to Windsufing in San Francisco [1]. I hope it stays.

[1]: https://vimeo.com/77666233

I grew up in the central valley in California and it is already very noticeable how much less tule fog [1] there is from just a few decades ago. It just doesn't get as cool at night and humidity is lower on average and that significantly reduces the fog formation.

[1] https://en.wikipedia.org/wiki/Tule_fog

I once drove through Dinuba with my head out the window to try to see past the hood of my car, it was crazy.

Agreed. We did get a few days of the real thing this past winter, which was a nice surprise, but it used to happen a lot.

Ah, the days of driving home from a date in that fog. Had to drive with your head out the window because of the fog outside and inside. :-)

Someone else posted this below https://news.ycombinator.com/item?id=32858258 that is not mentioned in the wikipedia page:

> Falling levels of air pollution drove decline in California’s tule fog

The offshore california current transports cold surface water from the Gulf of Alaska down coast, and there's wind- and current-forced upwelling of deep, cold nutrient-rich water from the deep Pacific Basin. The interaction of cold water and warm air leads to condensation at the near-ocean surface, aka fog (marine layer) formation. This effect persists as far south as Point Conception north of the Los Angeles basin. A warmer climate implies an atmosphere capable of holding more water vapor before condensation takes place, but the transition from clear moist air to opaque cloud is complicated and hard to model precisely:

https://www.usgs.gov/centers/western-geographic-science-cent...

> "Fog pushes against, over, and through gaps in the coastal mountains, transporting water and other aerosol materials into coastal ecosystems. If the temperature or pressure differences (gradients) are too strong, winds will be generated and the additional turbulent mixing will dissipate the fog."

Across most of California the Coast Ranges block the inland movement of the offshore marine layer in summer, with the break in the ranges at the San Francisco Bay the marine layer can flow in and out without having to climb the ranges and waterfall down the other side (that's an impressive sight when it does). As far as climate, the physical flow of the California Current is driven by planetary rotation, but the Gulf of Alaska has been generally warming and experiencing heatwaves, so perhaps some warming of the California Current is expected:

https://www.fisheries.noaa.gov/feature-story/central-gulf-al...

Sometimes the atmospheric outflow from the hot Central Valley through the Bay gap is strong enough to keep the fog bank well offshore (or dissolve it altogether). It comes down to the dynamics of local winds, the temperature differential (colder ocean = more fog, hotter valley air outflow = less onshore fog). Climate-wise, the California Central Valley is getting warmer with more extreme heat days:

https://blog.ucsusa.org/pablo-ortiz/climate-change-impacts-o...

Thus, less fog coming into the SF Bay is a reasonable prediction.

Not sure how the Tule fog related to the SF fog, but:

https://news.berkeley.edu/2019/04/10/falling-levels-of-air-p...

It's definitely getting less foggy in the summers. People in the east side of San Francisco are installing AC or wishing they had AC.

Could that also be due to transplants? 80% of people in SF apparently don’t stay that long and move out. I can easily imagine someone moving to SF and enjoying the nice temps most of the year.

The two weeks of high heat that everyone on California coasts experiences can cause such people to freak out and want an AC instead of dealing with it or going outside. I live in a coastal city where it’s 70 basically every day except for 10 days of the year when it can be high 80s/90s. Just get a fan.

I moved here in '93. I'm not a native, but I don't think I can be considered transient.

I got an AC unit for the first time two years ago. Following tradition, it didn't arrive until I didn't need it, but I ran it last year, and then a lot this year.

I live in SOMA, it is usually a couple degrees warmer here than the city average. But that doesn't account for the 99F reading on my outside thermometer last week.

I’m not talking about you because you’ve been there for years now.

I meant that most people move to SF for a couple years and then move out due to costs or whatever reason. I read somewhere that 80% or so of SF is this way. Students, job hoppers, workers, etc.

How was SF in the 90s?

Redwood City here, just bought my first (window) A/C for my house this summer. It went from "if I'm going to buy one, I should do it now before it gets really hot" to "I'm buying one today". So thankfully I had it for all of the hot days this year, including the record high 107 last week.

No, these are not transplants freaking out because of two weeks per year.

Wouldn't a transplant arguably find the weather (with occasional 'heatwaves' more tolerable than a native who's grown soft?

Can confirm, installed central air AC (and improved insulation) at my place this year in Potrero Hill. Costly given labor and permit BS in SF. It’s consistently hotter than 20 years ago to. I had 80F+ in my house during 1/3rd of the year at 4pm over the last 3 years. Barely get any fog these days in my hood.

Redwood trees need the moisture in the air. Some of those trees are a couple thousand years old. Is this the end for Redwoods?

https://www.nps.gov/redw/learn/nature/about-the-trees.htm

The redwood forests around south bay / santa cruz are showing stress. There are many dead ones in parks in silicon valley. Here's an article about drought and albino redwoods from last year:

https://www.sfgate.com/california-parks/article/California-a...

This year was even drier.

Our forests are in really sad shape in 2022. Nothing like what I remember as kid, so many dead trees now.

The archive.ph link for the article lacks much of the interactive experience.

The gift link for it - https://www.nytimes.com/interactive/2022/09/14/climate/san-f...

Not sure if there would be anyone old enough here - but all the old San Francisco Film Noirs from the 40s and 50s show SF and pouring rain.

Was that real or just a Hollywood thing?

SF does pour rain fairly often between January and March, those films could have chosen the time of year for the desired atmosphere.

Not anymore. It used too every year, hardly ever now.

I grewup in the bay area (peninsula) and was in SF a lot. It definitely rained a hell of a lot more. The weather now is practically like what people used to think of as Santa Monica weather half the year (or maybe Santa Barbara)

They say SF will be San Diego in 50 years, so perhaps still liveable.

We can’t all live forever, right Karl?

https://twitter.com/KarlTheFog/status/1570499729813012480?s=...

Biking across the golden gate bridge when the fog and wind is blowing through from the Pacific is one of the most immersive (and scary) experiences ever. Highly recommend!

Try doing it from the top of a Big Bus too! Amazing!

Yes it would be sad if it were totally gone but let’s not imagine that it’s great living in a super foggy place where you lose the ability to appreciate the natural beauty of your neighborhood. The foggiest parts of the city also generally have the worst weather overall. I’m sure there are some people that really like it but generally speaking it’s not desirable to have high winds and dense fog.

the fog is part of the natural beauty

Yes and it looks great from a distance but it can be foggy like all day, for days at a time, you want to raise kids there? Where I lived the sun would usually come out (thankfully) but it would take until 3pm.

My sister-in-law moved to SF from Chicago, and every time we met up with them further south on the Peninsula, she'd remark "oh, it turned into a nice day!"

The fog doesn’t hide the beauty; the fog is the beauty.

Nice to visit, but you wouldn’t want to live there.

I do live there. I can hear the foghorns from the bridge at night. It’s nice!

I grew up in Sacramento. The fog has gone from ubiquitous to nearly completely gone.

One good thing about less fog: fewer canceled flights from SFO.

The cost is greater than the benefit.

What's the benefit of fog?

You read this backwards: the cost of less fog is greater than the benefit of less fog (though I also feel like that comment took the comment it was responding to way too seriously...).

Increasing the separation between runways would be sufficient to get most of the way there; planes can be landed solely on instruments if the runways are far enough apart.

Is there physical space for this?

You may find historical maps of SFO helpful:

- https://www.sfomuseum.org/about/blog/interactive-historic-ma...

- https://millsfield.sfomuseum.org/map/

Much of the current runways are on what was part of the water in the bay just 100 years ago.

There's more to it than runway spacing, of course. The runway and the aircraft both must have the necessary equipment installed, and the flight crew has be trained and certified in its use.

More pollution yay

SFO flights usually get cancelled because of cross winds, not fog.

Fog is a common reason for delayed flights into SFO, as reduced visibility prevents planes from being able to land side by side, halving the rate at which planes are able to land [1]. I don't know if this leads to many flights being canceled outright, but I have certainly experienced massive delays flying into SFO due to fog - typicially on shorter regional flights where ATC will prevent your plane from even taking off at the point of departure due to congestion at SFO.

[1] https://www.kqed.org/news/11772407/why-is-sfo-so-delayed

Is it possible to destroy the fog completely via weather engineering?

If the land and the ocean are the same temperature there won't be fog so just make the ocean 100 degrees problem solved.

What is with all these "experts fear this might happen" articles?

It's weird. Not enough actual news to cover?

Normally we ask experts to give their expert opinions.

I don't think the NYT (or anyone, really) is hurting for news to cover either. It's been an exciting year.

Sure, but so many articles are about some doomsday scenario that experts "aren't sure will happen, but might".

Seems like there is enough stuff happening right now that could fill the pages rather than attempts at predicting the future?

News is highly undifferentiated. If you want to stand out among the copycat news sources you also need to provide long form articles and a distinctive slant, which NYT has spent the last decade building.

Also, this kind of long form investigative journalism is what has died out in most newsrooms in an effort to reduce costs.

We already pretty much killed local news, no need to reduce everything to an AP feed.

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