8 ms·

300 meters resolution SF Bay Area Forecast

169 points by johmathe 4y ago

rnk 4y ago
Interesting. Their website has a real "Delos" feel, as in the West World corporation. I'd love a narrow cast for my area too. You could sell access to these maybe.
CoffeeOnWrite 4y ago
Very cool. Pedantic but suggest title rename to say “SF Bay Area” or “inner SF Bay Area”. SF is just a small portion of the coverage area.
- deleted 4y ago
  [deleted]
1-6 4y ago
TIL Mt Diablo gets cold
- latchkey 4y ago
  It even snows! https://www.sfgate.com/weather/article/Mount-Diablo-Bay-Area-snow-day-16735049.php https://www.sfgate.com/weather/article/Mount-Diablo-Bay-Area...
nathancahill 4y ago
Wow, this is the future.
- pvarangot 4y ago
  Literally
- lostlogin 4y ago
  I wish it was. I see no sign that forecasting has improved at all in my part of the world. Auckland, New Zealand.
  - nikisweeting 4y ago
    This release is just for the SF bay area, their models for elsewhere are not released publicly yet.
2Pacalypse- 4y ago
This is pretty cool if I do say so myself. What does the picnic data show?
- johmathe 4y ago
  It’s a forecast of the best spots to have a picnic in the bay :) Basically a proxy for the best place and time to be outdoors.
cleandreams 4y ago
Yes, yes, yes. Great. Thanks. Bookmarked!
mistrial9 4y ago
fun - but I am reminded of the excoriation that Windy-dot-com got here on YNews when facts-oriented people started comparing the visualization to more quantitative sources.. snipes aside, no doubts here that they will sell this and be paid for it.
blululu 4y ago
That is impressive. Pretty accurate about the early morning cold spots. Not sure how much of this is just matching historical trends (SF has a pretty consistent climate), but the level of spatial resolution on the data is amazing. Not sure how they did it really.
misradeepika 4y ago
I’m loving the picnic mode!!!!
georgeburdell 4y ago
Not working on my iphone. Slashdotted?
Waterluvian 4y ago
A few thoughts from a geographer (be prepared to shoot me): - Basically every comment is wowed by this, but nobody questions what the accuracy is. I, too, can Krig interpolated surfaces to any resolution. - off-nadir view doesn't seem to offer much - We've been dealing with janky tile loading for like 20 years now. I really hope we'll get a much smoother approach for viewing these tiles as they load. The dissolve transition hides it a bit, but makes the data uncomfortable to view when playing the timeseries. - I'm deeply curious about the Picnic data layer. Can someone share the ArcGIS/QGIS model for that one? =D
- wmeredith 4y ago
  Thanks for chiming in. I can make an animation say whatever I want. I am very curious about the accuracy. Unrelated: The site breaks my back button in Chrome, which is an unforgivable UI sin.
  - johmathe 4y ago
    Thanks for the feedback. We will have the back button fixed quickly :)
    - thot_experiment 4y ago
      Same thing in firefox, and pleeease have a units switch. Would be infinitely more useful if I could view the site in the units my brain normally works in rather than having to think about the conversion all the time. Very cool site otherwise, also very cool bay area right now.
      - johmathe 4y ago
        All fixed up and deployed.
        thot_experiment 4y ago
        <3 thank you for the quick fix! no unit switch yet right, or am I missing it?
bombela 4y ago
How do you switch to normal (for 97% of humans) units for temperature and wind?
- deleted 4y ago
  [deleted]
- froidpink 4y ago
  The heaviest users of wind forecasting use knots
- pklausler 4y ago
  I learned to interpret wind speeds in m/s on a visit to Iceland and found it to be an intuitive unit for hiking and other outdoor purposes. And 1m/s is pretty close to 2 knots so it's easy to convert.
- johmathe 4y ago
  We will be adding the Celsius switch shortly. We started with F since we expected most users of the forecast to be in the bay area but it is great to see interest from non Fahrenheit users :)
  - bombela 4y ago
    The bay area is probably the place with the fewest native users of Fahrenheit in the whole USA. All those US customary units should never be the default in 2022. It's time to move on people. The whole world and the majority of the industry in the USA share the same system of measure. Let's get the American population there too.
modzu 4y ago
shameless plug of my little rain map that has the opposite approach -- zero interpolation, zero forecasting. just the real data from the radar feed in 10 meter resolution at the current time (plus 3 past snapshots at 1 hour intervals): https://truweather.link https://truweather.link and the app versions: https://play.google.com/store/apps/details?id=net.conceptualspace.trueweather https://play.google.com/store/apps/details?id=net.conceptual... https://apps.apple.com/ca/app/truweather/id1537614881 https://apps.apple.com/ca/app/truweather/id1537614881 i find it useful because every other weather app is wrong in some way ;) instead, it enables you to form your own mental models
nfriedly 4y ago
What does "300 meters resolution" mean in this context?
- lispisok 4y ago
  Weather models divide the atmosphere into cells where each cell has it's own forecast. There are several ways to do it but if you imagine the cells as cubes, the north-south and east-west dimensions of the cube is 300m long. 300m is very high resolution for weather models with most running at a few kilometers to a few dozen kilometers.
- johmathe 4y ago
  It means that the underlying weather data is computed and validated at a 300x300 meters resolution. Hope this helps :)
  - carabiner 4y ago
    How are you doing validation?
- swimfar 4y ago
  Also note that it should be "300 meter resolution". You don't use a plural when using it as an adjective. I only point this out to help people because this is a common grammar mistake for non-native speakers.
lispisok 4y ago
If I had to guess they are running the WRF model [1][2]. The AI part is post-processing the model output. With a fair amount of reading the manual anybody can run their own WRF. WRF scales from running on a laptop to supercomputers with 1000s of cores. [1] https://www.mmm.ucar.edu/models/wrf https://www.mmm.ucar.edu/models/wrf [2] https://github.com/wrf-model/WRF https://github.com/wrf-model/WRF
- RosanaAnaDana 4y ago
  I mean up or downsampling is trivial. The question isn't if you can make a raster at any resolution, its if you can make a raster thats accurate and precise at that resolution. Its not clear to me that this is either.
  - johmathe 4y ago
    One of the interesting things the model captures at this resolution is the dynamics of the wind going in the bay through the golden gate. See for instance: https://sf.atmo.ai/wind@37.80911,-122.44543,11.68,36,0,1666917526 https://sf.atmo.ai/wind@37.80911,-122.44543,11.68,36,0,16669...
    - zsz 4y ago
      The Global Forecast System (GFS), i.e. the model presently used at NCEP, has a grid resolution of 18 miles (28 km). It is (has been, for years, actually), the second best global forecast system, right behind the European ECMWF (sometimes outperforming it, but on average slightly underperforming it, in terms of accuracy). I don't know how the ECMWF model works, but even as someone who did not study meteorology (but studied electrical engineering, which forms the theoretical basis of weather forecasting via the Kalman filter), I can say the following (having spent a number of years working at NCEP): 1. Initial conditions/parameters are fundamental in setting up a model run. 2. Forecasts have for a long time relied on ensembles, which are repeat model runs with slightly varying parameters. The idea of ensembles is, if you run enough of them, you will frequently notice one or more convergence(s) that various sets of parameters produce, e.g. where some sets of parameters predict one movement pattern for a hurricane, while others produce a different movement pattern. Historically, such discrepancies were resolved by actual forecasters, who decided based on their knowledge and experience which one was more likely. In addition, they also had meetings every morning between scientists (developing the model) and forecasters (who relied more on general knowledge and experience) and involved occasionally heated discussions between the groups. But I digress. 3. Considering it involves a chaotic system, I cannot say how much value something like deep learning might bring to the table that produces consistent value above and beyond what's already obtained by using ensembles of Kalman predictive filtering. It is however noteworthy to point out that if the grid resolution is 28,000 meters, then it may not make much sense to set the resolution of the model itself substantially lower (like 300 meters), because any resulting data is more likely to be an artifact of the model itself, rather than reflective of real life information. Luckily, this issue has been and is being addressed through the development of rigorous testing standards, which inform of the inherent quality of forecasts produced by a particular model (this is how they can assign an objective rank to e.g. the GFS and the ECMWF, when forecast quality is generally very close and the model producing the most accurate prediction varies between the two). To put it plainly, the degree to which the website mentioned above has any value is based not on its best predictions, but on the overall variance (i.e. how close predicted data comes to actual measurements of the same, which is necessarily retrospective). 4. That said, it's worthwhile to point out that just because it doesn't involve a government agency with something like a thousand employees, hundreds of scientists (in the case of NCEP alone), and very powerful supercomputers, does not necessarily mean it's bunk (even if it frequently does). For example, I do recall Panasonic (IIRC) showing up out of the blue, with its own forecasting system, which was shown to be competitive after requisite, rigorous testing. I don't remember many details and this was years ago—and its disappearance alone is suspect, but it's worth adding for completeness.
nicolashahn 4y ago
I've been wanting this for a long time. Any way I could get it as a live updating widget for my Android home screen?
dopeboy 4y ago
Opportune day you picked to share this, given this nasty cold front. Very cool.
asdff 4y ago
This needs to be done for more cities in California, especially Los Angeles with its huge geographic area and all the diverse micro climates contained within. Sometimes the weather changes more than 15 degrees in half as many miles from the coast. It therefore doesn't make sense to e.g. check "weather in LA" when its going to be somewhat wrong most of the time depending on where in LA you happen to be, since the little widget that pops up on google search for "weather in LA" doesn't exactly tell you where in the 500sq miles of LA they are putting the temperature probe.
- issa 4y ago
  I feel like you could make a whole movie about the weather in LA. It would change your life. Twice.
  - PaulHoule 4y ago
    That's true, but an upstate New Yorker would wonder what the fine resolution forecast looks like for a place that really has weather.
  - spullara 4y ago
    Recognized the reference immediately. What a movie. https://tvtropes.org/pmwiki/pmwiki.php/Film/LAStory https://tvtropes.org/pmwiki/pmwiki.php/Film/LAStory
  - CalChris 4y ago
    Not weather, sun, sun, sun, sun, sun!
- sosodev 4y ago
  Same thing in San Diego. I feel like the popular weather services can't make accurate predictions or even tell what is happening most of the time. My iPhone will tell me it's raining when it's sunny outside.
syntaxing 4y ago
How much computational power does it take to make something like this?
RosanaAnaDana 4y ago
so whats the RMSE and how do we know that?
orangepurple 4y ago
Looks amazing! However, this model (like all models by default) is not validated and produces garbage unless proven otherwise.
modo_ 4y ago
Running over in Rodeo valley (Marin) there was a very noticeable (and unusual) inversion this morning around 7:30 am. It must have been 5-10 degrees colder on the valley floor compared to up higher -- after ~100ft of elevation gain up out of the valley it warmed up very rapidly. I don't see that reflected in this map at all fwiw. https://sf.atmo.ai/temperature@37.83200,-122.51075,13.53,20,0,1666886651 https://sf.atmo.ai/temperature@37.83200,-122.51075,13.53,20,...
- Workaccount2 4y ago
  It's likely because services like these use models as data feeds and not live/recorded data.
zestyping 4y ago
Is there a Celsius mode?
anyfoo 4y ago
Growing up in Germany, before I moved to the Bay Area, I was wondering why weather apps and widgets were so prolific. Sure, knowing the forecast for next weekend was nice, but for anything closer I'd just get out of bed and look out of the window. That would pretty much tell me what weather it is, and it would usually change just slowly over a few days or so. Then I moved to the Bay Area, and weather does not only change quickly, it may also be vastly, vastly different just a short distance away. Temperature differentials of 10°C or more within just 40 miles are interesting enough that it's a frequent topic of conversation with friends in Germany. Everything suddenly made sense. The weather widgets. The hoodies: Easy to put on or off.
- anyfoo 4y ago
  Another anecdote: In the South of Germany at least, long stretches of sunny days are often followed by sudden thunderstorms with equally sudden bursts of rain. That "fact" had been so deeply ingrained in me that it was subconscious. You'd have a careful feeling if it was hot for too long, suddenly you might find yourself running for the next awning to escape the torrential rain. Sunny weather was a bit like building up a sort of pressure, that must release violently. Took a while to let go of that feeling in California. It basically rains in winter, and does not rain in summer. Like, at all. (Note that I moved away about a decade ago, climate may have changed in the meantime.)
  - dan-robertson 4y ago
    I hadn’t even thought of that until I read this. I had thought thunderstorms after hot weather were just a fact of life. I guess in places near German latitudes that get thunderstorms the hot weather is caused by high pressure systems but maybe that isn’t really the cause in California.
    - barbazoo 4y ago
      Coastal weather is often lacking the conditions that creates thunderstorms. I live near the coast now too and haven't experienced the kind of thunderstorm I know from Germany.
londons_explore 4y ago
Weather forecasts are so hard for a user to evaluate... Are you going to check it every day and remember how many days it was right or wrong? Please can weather providers just publish a headline statistic of "Our rain/no rain one day ahead forecast is right 85% of the time. That is better than NOAA (80%), Met Office (72%) and weather.com (65%)."
- nikisweeting 4y ago
  Atmo built their business on beating their competitors on a particular ranking metric that does exactly as you describe. I discussed it with the founder but am not sure how much of that convo was public info so I hope they post it here.
- carabiner 4y ago
  This is kind of the purpose of the "50% chance of rain" things. The process is called calibration and is usually done with linear regression, and it means that in historical forecasts, the actual outcome was rain 50% of the time. Surface precip is notoriously hard to predict, so this is what we've got right now.
  - londons_explore 4y ago
    But they should publish that... And then compare that figure to their competitors... To demonstrate to their users that their service is actually better, not just has a shinier UI...
  - tiagod 4y ago
    Would be nice to have some extra error information. Like a probability for a number of mm precipitation buckets.
- namibj 4y ago
  On part that's what ensembles are about: they run like 20 or so simulations of the near future, randomizing the start values and simulation parameters within the range of uncertainty, and get one potential future per simulation out of the process. A 30% rain chance every hour of the entire afternoon until sunset tends to be less actionable than "85% chance of a 50~80 minute rain shower during the afternoon, unclear when, but likely a bit longer if it'd start very late", as one can often adapt around such, for example by scheduling the homework to get done "wherever it's raining, at the latest so it'll be finished by dinner time", spending the dry time with outdoor physical activity that doesn't care about wet ground (but getting wet from above isn't nice).
s1artibartfast 4y ago
Very interesting data but infuriating UI. With so much heat map display, why is there no key? For wind, red/purple are counterintuitively lower speed than orange and yellow? Also, who do so many applications force oblique views?
- lucasmullens 4y ago
  > Also, who do so many applications force oblique views? I'm able to adjust it by dragging with two fingers on my trackpad, which I think is the standard behavior for that (albeit hard to discover). But I do agree, it's weird for that to be the default. There's also probably no key because the colors are mostly transparent, so it would be hard to make a key easy to understand. Labelling the contour lines seems like a reasonable approach imo.
  - s1artibartfast 4y ago
    Interesting, I don't get Contour labels on mine, so I have to continually reposition to get a sense of the magnitude
FullyFunctional 4y ago
Sorry, I’m from the present. How does one change it to Celcius?
geuis 4y ago
Pretty cool, but the map really needs to have a street label option.
bandyaboot 4y ago
The secret sauce to making accurate forecasts at 300 meter resolution has to be something more than “AI” right? I mean, there’s little reason to think AI should be meaningfully better at filling in details at 300m resolution than it would be at picking lottery numbers, no? Am I thinking about this wrong?
- labster 4y ago
  Nah, just run the WRF model at a 300m horizontal resolution and use a regional model or GCM for the boundary conditions. No AI necessary.
evilotto 4y ago
There's lots of weird little vortices where the wind seems to start or end in a spiral. I'm guessing it's an artifact of the modelling. Funny, but overall very cool.
keepquestioning 4y ago
Is there a site that predicts the movement of SF fog?
sailor1234 4y ago
Love the app. The details that the map is displaying is really important if you want to know the forecast for a specific location, which is really important if you're on the sea or in the air. Looking forward to have the forecast for even more locations around the world
_tom_ 4y ago
Displays nothing but garbage on mac/firefox. I did briefly see something that looked like a map, but then it smeared into an abstract art looking blob.

169 points by johmathe 4y ago

rnk 4y ago

Interesting. Their website has a real "Delos" feel, as in the West World corporation. I'd love a narrow cast for my area too. You could sell access to these maybe.

CoffeeOnWrite 4y ago

Very cool. Pedantic but suggest title rename to say “SF Bay Area” or “inner SF Bay Area”. SF is just a small portion of the coverage area.

deleted 4y ago
[deleted]

1-6 4y ago

TIL Mt Diablo gets cold

latchkey 4y ago
It even snows! https://www.sfgate.com/weather/article/Mount-Diablo-Bay-Area-snow-day-16735049.php https://www.sfgate.com/weather/article/Mount-Diablo-Bay-Area...

nathancahill 4y ago

Wow, this is the future.

pvarangot 4y ago
Literally
lostlogin 4y ago
I wish it was. I see no sign that forecasting has improved at all in my part of the world. Auckland, New Zealand.
- nikisweeting 4y ago
  This release is just for the SF bay area, their models for elsewhere are not released publicly yet.

2Pacalypse- 4y ago

This is pretty cool if I do say so myself. What does the picnic data show?

johmathe 4y ago
It’s a forecast of the best spots to have a picnic in the bay :) Basically a proxy for the best place and time to be outdoors.

cleandreams 4y ago

Yes, yes, yes. Great. Thanks. Bookmarked!

mistrial9 4y ago

fun - but I am reminded of the excoriation that Windy-dot-com got here on YNews when facts-oriented people started comparing the visualization to more quantitative sources.. snipes aside, no doubts here that they will sell this and be paid for it.

blululu 4y ago

That is impressive. Pretty accurate about the early morning cold spots. Not sure how much of this is just matching historical trends (SF has a pretty consistent climate), but the level of spatial resolution on the data is amazing. Not sure how they did it really.

misradeepika 4y ago

I’m loving the picnic mode!!!!

georgeburdell 4y ago

Not working on my iphone. Slashdotted?

Waterluvian 4y ago

A few thoughts from a geographer (be prepared to shoot me): - Basically every comment is wowed by this, but nobody questions what the accuracy is. I, too, can Krig interpolated surfaces to any resolution. - off-nadir view doesn't seem to offer much - We've been dealing with janky tile loading for like 20 years now. I really hope we'll get a much smoother approach for viewing these tiles as they load. The dissolve transition hides it a bit, but makes the data uncomfortable to view when playing the timeseries. - I'm deeply curious about the Picnic data layer. Can someone share the ArcGIS/QGIS model for that one? =D

wmeredith 4y ago
Thanks for chiming in. I can make an animation say whatever I want. I am very curious about the accuracy. Unrelated: The site breaks my back button in Chrome, which is an unforgivable UI sin.
- johmathe 4y ago
  Thanks for the feedback. We will have the back button fixed quickly :)
  - thot_experiment 4y ago
    Same thing in firefox, and pleeease have a units switch. Would be infinitely more useful if I could view the site in the units my brain normally works in rather than having to think about the conversion all the time. Very cool site otherwise, also very cool bay area right now.
    - johmathe 4y ago
      All fixed up and deployed.
      - thot_experiment 4y ago
        <3 thank you for the quick fix! no unit switch yet right, or am I missing it?

bombela 4y ago

How do you switch to normal (for 97% of humans) units for temperature and wind?

deleted 4y ago
[deleted]
froidpink 4y ago
The heaviest users of wind forecasting use knots
pklausler 4y ago
I learned to interpret wind speeds in m/s on a visit to Iceland and found it to be an intuitive unit for hiking and other outdoor purposes. And 1m/s is pretty close to 2 knots so it's easy to convert.
johmathe 4y ago
We will be adding the Celsius switch shortly. We started with F since we expected most users of the forecast to be in the bay area but it is great to see interest from non Fahrenheit users :)
- bombela 4y ago
  The bay area is probably the place with the fewest native users of Fahrenheit in the whole USA. All those US customary units should never be the default in 2022. It's time to move on people. The whole world and the majority of the industry in the USA share the same system of measure. Let's get the American population there too.

modzu 4y ago

shameless plug of my little rain map that has the opposite approach -- zero interpolation, zero forecasting. just the real data from the radar feed in 10 meter resolution at the current time (plus 3 past snapshots at 1 hour intervals): https://truweather.link https://truweather.link and the app versions: https://play.google.com/store/apps/details?id=net.conceptualspace.trueweather https://play.google.com/store/apps/details?id=net.conceptual... https://apps.apple.com/ca/app/truweather/id1537614881 https://apps.apple.com/ca/app/truweather/id1537614881 i find it useful because every other weather app is wrong in some way ;) instead, it enables you to form your own mental models

nfriedly 4y ago

What does "300 meters resolution" mean in this context?

lispisok 4y ago
Weather models divide the atmosphere into cells where each cell has it's own forecast. There are several ways to do it but if you imagine the cells as cubes, the north-south and east-west dimensions of the cube is 300m long. 300m is very high resolution for weather models with most running at a few kilometers to a few dozen kilometers.
johmathe 4y ago
It means that the underlying weather data is computed and validated at a 300x300 meters resolution. Hope this helps :)
- carabiner 4y ago
  How are you doing validation?
swimfar 4y ago
Also note that it should be "300 meter resolution". You don't use a plural when using it as an adjective. I only point this out to help people because this is a common grammar mistake for non-native speakers.

lispisok 4y ago

If I had to guess they are running the WRF model [1][2]. The AI part is post-processing the model output. With a fair amount of reading the manual anybody can run their own WRF. WRF scales from running on a laptop to supercomputers with 1000s of cores. [1] https://www.mmm.ucar.edu/models/wrf https://www.mmm.ucar.edu/models/wrf [2] https://github.com/wrf-model/WRF https://github.com/wrf-model/WRF

RosanaAnaDana 4y ago
I mean up or downsampling is trivial. The question isn't if you can make a raster at any resolution, its if you can make a raster thats accurate and precise at that resolution. Its not clear to me that this is either.
- johmathe 4y ago
  One of the interesting things the model captures at this resolution is the dynamics of the wind going in the bay through the golden gate. See for instance: https://sf.atmo.ai/wind@37.80911,-122.44543,11.68,36,0,1666917526 https://sf.atmo.ai/wind@37.80911,-122.44543,11.68,36,0,16669...
  - zsz 4y ago
    The Global Forecast System (GFS), i.e. the model presently used at NCEP, has a grid resolution of 18 miles (28 km). It is (has been, for years, actually), the second best global forecast system, right behind the European ECMWF (sometimes outperforming it, but on average slightly underperforming it, in terms of accuracy). I don't know how the ECMWF model works, but even as someone who did not study meteorology (but studied electrical engineering, which forms the theoretical basis of weather forecasting via the Kalman filter), I can say the following (having spent a number of years working at NCEP): 1. Initial conditions/parameters are fundamental in setting up a model run. 2. Forecasts have for a long time relied on ensembles, which are repeat model runs with slightly varying parameters. The idea of ensembles is, if you run enough of them, you will frequently notice one or more convergence(s) that various sets of parameters produce, e.g. where some sets of parameters predict one movement pattern for a hurricane, while others produce a different movement pattern. Historically, such discrepancies were resolved by actual forecasters, who decided based on their knowledge and experience which one was more likely. In addition, they also had meetings every morning between scientists (developing the model) and forecasters (who relied more on general knowledge and experience) and involved occasionally heated discussions between the groups. But I digress. 3. Considering it involves a chaotic system, I cannot say how much value something like deep learning might bring to the table that produces consistent value above and beyond what's already obtained by using ensembles of Kalman predictive filtering. It is however noteworthy to point out that if the grid resolution is 28,000 meters, then it may not make much sense to set the resolution of the model itself substantially lower (like 300 meters), because any resulting data is more likely to be an artifact of the model itself, rather than reflective of real life information. Luckily, this issue has been and is being addressed through the development of rigorous testing standards, which inform of the inherent quality of forecasts produced by a particular model (this is how they can assign an objective rank to e.g. the GFS and the ECMWF, when forecast quality is generally very close and the model producing the most accurate prediction varies between the two). To put it plainly, the degree to which the website mentioned above has any value is based not on its best predictions, but on the overall variance (i.e. how close predicted data comes to actual measurements of the same, which is necessarily retrospective). 4. That said, it's worthwhile to point out that just because it doesn't involve a government agency with something like a thousand employees, hundreds of scientists (in the case of NCEP alone), and very powerful supercomputers, does not necessarily mean it's bunk (even if it frequently does). For example, I do recall Panasonic (IIRC) showing up out of the blue, with its own forecasting system, which was shown to be competitive after requisite, rigorous testing. I don't remember many details and this was years ago—and its disappearance alone is suspect, but it's worth adding for completeness.

nicolashahn 4y ago

I've been wanting this for a long time. Any way I could get it as a live updating widget for my Android home screen?

dopeboy 4y ago

Opportune day you picked to share this, given this nasty cold front. Very cool.

asdff 4y ago

This needs to be done for more cities in California, especially Los Angeles with its huge geographic area and all the diverse micro climates contained within. Sometimes the weather changes more than 15 degrees in half as many miles from the coast. It therefore doesn't make sense to e.g. check "weather in LA" when its going to be somewhat wrong most of the time depending on where in LA you happen to be, since the little widget that pops up on google search for "weather in LA" doesn't exactly tell you where in the 500sq miles of LA they are putting the temperature probe.

issa 4y ago
I feel like you could make a whole movie about the weather in LA. It would change your life. Twice.
- PaulHoule 4y ago
  That's true, but an upstate New Yorker would wonder what the fine resolution forecast looks like for a place that really has weather.
- spullara 4y ago
  Recognized the reference immediately. What a movie. https://tvtropes.org/pmwiki/pmwiki.php/Film/LAStory https://tvtropes.org/pmwiki/pmwiki.php/Film/LAStory
- CalChris 4y ago
  Not weather, sun, sun, sun, sun, sun!
sosodev 4y ago
Same thing in San Diego. I feel like the popular weather services can't make accurate predictions or even tell what is happening most of the time. My iPhone will tell me it's raining when it's sunny outside.

syntaxing 4y ago

How much computational power does it take to make something like this?

RosanaAnaDana 4y ago

so whats the RMSE and how do we know that?

orangepurple 4y ago

Looks amazing! However, this model (like all models by default) is not validated and produces garbage unless proven otherwise.

modo_ 4y ago

Running over in Rodeo valley (Marin) there was a very noticeable (and unusual) inversion this morning around 7:30 am. It must have been 5-10 degrees colder on the valley floor compared to up higher -- after ~100ft of elevation gain up out of the valley it warmed up very rapidly. I don't see that reflected in this map at all fwiw. https://sf.atmo.ai/temperature@37.83200,-122.51075,13.53,20,0,1666886651 https://sf.atmo.ai/temperature@37.83200,-122.51075,13.53,20,...

Workaccount2 4y ago
It's likely because services like these use models as data feeds and not live/recorded data.

zestyping 4y ago

Is there a Celsius mode?

anyfoo 4y ago

Growing up in Germany, before I moved to the Bay Area, I was wondering why weather apps and widgets were so prolific. Sure, knowing the forecast for next weekend was nice, but for anything closer I'd just get out of bed and look out of the window. That would pretty much tell me what weather it is, and it would usually change just slowly over a few days or so. Then I moved to the Bay Area, and weather does not only change quickly, it may also be vastly, vastly different just a short distance away. Temperature differentials of 10°C or more within just 40 miles are interesting enough that it's a frequent topic of conversation with friends in Germany. Everything suddenly made sense. The weather widgets. The hoodies: Easy to put on or off.

anyfoo 4y ago
Another anecdote: In the South of Germany at least, long stretches of sunny days are often followed by sudden thunderstorms with equally sudden bursts of rain. That "fact" had been so deeply ingrained in me that it was subconscious. You'd have a careful feeling if it was hot for too long, suddenly you might find yourself running for the next awning to escape the torrential rain. Sunny weather was a bit like building up a sort of pressure, that must release violently. Took a while to let go of that feeling in California. It basically rains in winter, and does not rain in summer. Like, at all. (Note that I moved away about a decade ago, climate may have changed in the meantime.)
- dan-robertson 4y ago
  I hadn’t even thought of that until I read this. I had thought thunderstorms after hot weather were just a fact of life. I guess in places near German latitudes that get thunderstorms the hot weather is caused by high pressure systems but maybe that isn’t really the cause in California.
  - barbazoo 4y ago
    Coastal weather is often lacking the conditions that creates thunderstorms. I live near the coast now too and haven't experienced the kind of thunderstorm I know from Germany.

londons_explore 4y ago

Weather forecasts are so hard for a user to evaluate... Are you going to check it every day and remember how many days it was right or wrong? Please can weather providers just publish a headline statistic of "Our rain/no rain one day ahead forecast is right 85% of the time. That is better than NOAA (80%), Met Office (72%) and weather.com (65%)."

nikisweeting 4y ago
Atmo built their business on beating their competitors on a particular ranking metric that does exactly as you describe. I discussed it with the founder but am not sure how much of that convo was public info so I hope they post it here.
carabiner 4y ago
This is kind of the purpose of the "50% chance of rain" things. The process is called calibration and is usually done with linear regression, and it means that in historical forecasts, the actual outcome was rain 50% of the time. Surface precip is notoriously hard to predict, so this is what we've got right now.
- londons_explore 4y ago
  But they should publish that... And then compare that figure to their competitors... To demonstrate to their users that their service is actually better, not just has a shinier UI...
- tiagod 4y ago
  Would be nice to have some extra error information. Like a probability for a number of mm precipitation buckets.
namibj 4y ago
On part that's what ensembles are about: they run like 20 or so simulations of the near future, randomizing the start values and simulation parameters within the range of uncertainty, and get one potential future per simulation out of the process. A 30% rain chance every hour of the entire afternoon until sunset tends to be less actionable than "85% chance of a 50~80 minute rain shower during the afternoon, unclear when, but likely a bit longer if it'd start very late", as one can often adapt around such, for example by scheduling the homework to get done "wherever it's raining, at the latest so it'll be finished by dinner time", spending the dry time with outdoor physical activity that doesn't care about wet ground (but getting wet from above isn't nice).

s1artibartfast 4y ago

Very interesting data but infuriating UI. With so much heat map display, why is there no key? For wind, red/purple are counterintuitively lower speed than orange and yellow? Also, who do so many applications force oblique views?

lucasmullens 4y ago
> Also, who do so many applications force oblique views? I'm able to adjust it by dragging with two fingers on my trackpad, which I think is the standard behavior for that (albeit hard to discover). But I do agree, it's weird for that to be the default. There's also probably no key because the colors are mostly transparent, so it would be hard to make a key easy to understand. Labelling the contour lines seems like a reasonable approach imo.
- s1artibartfast 4y ago
  Interesting, I don't get Contour labels on mine, so I have to continually reposition to get a sense of the magnitude

FullyFunctional 4y ago

Sorry, I’m from the present. How does one change it to Celcius?

geuis 4y ago

Pretty cool, but the map really needs to have a street label option.

bandyaboot 4y ago

The secret sauce to making accurate forecasts at 300 meter resolution has to be something more than “AI” right? I mean, there’s little reason to think AI should be meaningfully better at filling in details at 300m resolution than it would be at picking lottery numbers, no? Am I thinking about this wrong?

labster 4y ago
Nah, just run the WRF model at a 300m horizontal resolution and use a regional model or GCM for the boundary conditions. No AI necessary.

evilotto 4y ago

There's lots of weird little vortices where the wind seems to start or end in a spiral. I'm guessing it's an artifact of the modelling. Funny, but overall very cool.

keepquestioning 4y ago

Is there a site that predicts the movement of SF fog?

sailor1234 4y ago

Love the app. The details that the map is displaying is really important if you want to know the forecast for a specific location, which is really important if you're on the sea or in the air. Looking forward to have the forecast for even more locations around the world

_tom_ 4y ago

Displays nothing but garbage on mac/firefox. I did briefly see something that looked like a map, but then it smeared into an abstract art looking blob.