[HN Gopher] Weather forecasts have become more accurate
___________________________________________________________________
Weather forecasts have become more accurate
Author : sohkamyung
Score : 206 points
Date : 2024-03-12 12:42 UTC (10 hours ago)
(HTM) web link (ourworldindata.org)
(TXT) w3m dump (ourworldindata.org)
| okdood64 wrote:
| Anecdotally, they have been very frustrating in the Bay Area with
| this El Nino rain season. Not as reliable. Many ruined plans, but
| I have learnt my lesson.
| bcardarella wrote:
| Not in Boston, they've become far far worse. I presume because of
| climate change but still has become frustrating in recent years.
| ejb999 wrote:
| why would you think that short term weather forecasts are
| somehow affected by climate change?
| Y-bar wrote:
| I don't think OP i correct that the forecasts there are less
| reliable, but I would gather that:
|
| More warming == more energy in the system.
|
| More energy in the system -> more volatile weather.
|
| More volatile weather -> harder to predict weather.
| dingnuts wrote:
| You gotta keep up with the narrative bud, it's not "weather
| isn't climate" anymore; as long as the weather seems unusual
| to adults, it's evidence of climate change.
|
| But don't forget! That doesn't mean nice weather is counter-
| evidence of climate change. Nice weather is /also/ evidence
| of climate change, because it's merely the lull before the
| weird weather.
|
| Got it yet?
| bcardarella wrote:
| Ok smoothbrain
| bcardarella wrote:
| Climate models are based upon historical data. Recent climate
| change has changed weather patterns where historical data
| being used is making predictions less reliable.
| Zamiel_Snawley wrote:
| Which forecasts have become worse in Boston? 24 hour, 5 day,
| all of the above? This is surprising to me, because even when
| traveling across the USA, I've found the predictions to be very
| useful.
| bcardarella wrote:
| All forecasts. I race sailboat around Boston and they've been
| absolutely horrible. Not just for extreme weather events but
| even regular weather wind direction is off by nearly 180
| degrees in direction regularly, wind strength is regularly
| wrong too. The predictions overemphasize rain events in the
| 10 day forecast during the Summer that nearly always
| completely go away and they fail to predict rain and
| lightning events. That's overing multiple weather models at
| various resolutions.
| jghn wrote:
| > they've become far far worse
|
| Where are your data to back this claim up? And over what time
| horizon?
| Zamiel_Snawley wrote:
| This article mostly discusses longer-term forecasts, but I have
| also been impressed with the quality and reliability of imminent-
| storm alerts. They have saved me from getting drenched in a rain
| storm or allowed me to pull off the road for a break before a
| downpour.
|
| It doesn't get a ton of press, but as this article highlights,
| progress has been steady and significant.
|
| This article asserts that improving forecasts in low-income
| countries is underrated--does anyone know of studies that predict
| the impact better forecasts would have? Helping the poor with
| tech seems like the kind of project that many philanthropists
| could get excited about, and hopefully more effective than
| gravity lights and the like.
| macintux wrote:
| As someone who drives much of the summer with no top on his
| Jeep, Dark Sky was a revelation. I also managed to find a route
| between two bands of heavy thunderstorms (with a tornado watch
| to boot) one night far from home with no top and no doors using
| the radar.
|
| Modern technology is amazing.
| darknavi wrote:
| > Dark Sky was a revelation
|
| Any replacement for it on iOS? Maybe I am crazy but Apple's
| weather alerts just don't seem like the same sauce.
| Larrikin wrote:
| I think they were doing some magic with the Android phone
| sensors, large amounts of user reports, as well as the
| actual forecast models.
|
| Before Apple bought them, my Android phone was its own
| party trick at the bar. I'd be able to tell people down to
| the minute when it would start and stop raining. It was
| amazing for bar hopping on bad weather days.
| counters wrote:
| Nope. Simple computer vision / optical flow applied to
| radar image sequences.
| declaredapple wrote:
| What the actual crap did Apple do to mess it up so bad
| then?
|
| Switching between providers on Carrot, Apple Weather
| often doesn't predict any amount of rain for the entire
| week, meanwhile I'm soaked in water in a thunderstorm,
| and NOAA and others predicted rain the entire week (which
| it did).
| counters wrote:
| No clue. They have strong folks on their weather team,
| too. Not obvious what's gone wrong over there.
| declaredapple wrote:
| Dark sky used to be accurate almost to the minute for me.
|
| Apple Weather will tell me it won't rain today or all week.
|
| Meanwhile NOAA will tell me I'm currently in a thunderstorm
| and that it will rain all week - And it was right.
|
| Carrot is nice because you can switch between several
| providers.
| redavni wrote:
| There is a gap between the title of the article and the contents.
| Starts out with weather forecasting is improved, but spends most
| of the article talking about how poor people and countries have
| other things to spend their money on than forecasting weather.
| throw0101d wrote:
| Recommend the book _The Weather Machine_ by Andrew Blume (also
| wrote _Tubes_ ) on some history of forecasting and what happens
| in the background nowadays:
|
| > _In The Weather Machine, Andrew Blum takes readers on a
| fascinating journey through an everyday miracle. In a quest to
| understand how the forecast works, he visits old weather stations
| and watches new satellites blast off. He follows the dogged
| efforts of scientists to create a supercomputer model of the
| atmosphere and traces the surprising history of the algorithms
| that power their work. He discovers that we have quietly entered
| a golden age of meteorology--our tools allow us to predict
| weather more accurately than ever, and yet we haven't learned to
| trust them, nor can we guarantee the fragile international
| alliances that allow our modern weather machine to exist._
|
| * https://www.andrewblum.net/the-weather-machine-2
|
| * https://www.goodreads.com/en/book/show/42079139
|
| For the very early history of meteorology, see perhaps _The
| Invention of Clouds_ about Luke Howard:
|
| * https://www.goodreads.com/book/show/1148768.The_Invention_of...
|
| * https://en.wikipedia.org/wiki/Luke_Howard
| LgWoodenBadger wrote:
| Maybe coincidentally related that Simpson's paradox article from
| earlier, but if they've gotten more accurate overall, I certainly
| do not see it in the 24-hour forecasts. Of course, I'm also
| probably only paying attention to when it's wrong, not when it's
| right.
|
| I plan my motorcycling based on rain, and the number of times
| I've gotten caught in rain when it wasn't supposed to rain at all
| that day is non-zero just this year.
| VHRanger wrote:
| Daily reminder that data isn't the multiple of anecdote.
| Izkata wrote:
| Except it literally is.
|
| That statement is pretty much only used as a thought-
| terminating cliche that means "you're not allowed to have an
| opinion".
| not2b wrote:
| No, it literally isn't, at least, the plural of anecdotes
| isn't _useful_ data. To be useful, data need to be
| collected in a uniform and systematic way. Anecdotes are
| memory, and it seems we are wired to remember the unusual
| and the unexpected. So you remember wrong forecasts
| (especially if you were caught outside unprepared), don 't
| remember correct forecasts. Collecting everyone's anecdotes
| would not give you any insight about how good or how bad
| forecasts are.
|
| Pointing this out is not an attempt to silence you.
| dataflow wrote:
| I'm sure they have, but I've also been drenched while reading a
| weather report that refused to admit it was raining in my city
| _right now_. It just told me it was cloudy, despite clear and
| rather heavy rain for 30+ mins straight over the whole city. To
| this day I haven 't figured out how that's even possible.
| n_plus_1_acc wrote:
| Depending in which sources they used, they simply interpolate
| on a very rough grid
| dataflow wrote:
| I mean, I guess, but how rough of a grid are we talking? This
| wasn't a tiny city or something... it was a pretty populated
| city spanning a few miles across in a very populated and well
| known region. Granted I didn't walk around to check the whole
| city for rain, but the sky didn't make it look like the
| clouds were only above my head...
| InSteady wrote:
| microbursts are a thing. It's entirely possible much of
| your city was dry despite the cloud cover. Also possible
| they just done goofed.
| NordSteve wrote:
| One factor is your distance from the nearest weather radar, and
| nearest airport with automated weather observation. This sort
| of prediction is heavily dependent on whether the precip is
| detected by sensing.
|
| I've seen similar things in our area (Minnesota) where you
| drive through a snowstorm, but the radar shows nothing in
| theare.
| cogman10 wrote:
| I've seen variations in weather literally 10 miles apart.
| With torrential rain at work and nothing at home.
|
| I can't see how any weather predictor could be correct in
| that situation.
| importantbrian wrote:
| Living in Florida I've driven down the road and had it be
| raining on one side of the road and not raining on the
| other while the sun is shining.
| bumby wrote:
| Was it saying there was 0% chance of rain or did it just not
| update to 100% even though you were experiencing rain?
|
| The latter is somewhat common because the models (AFAIK) use
| probabilistic estimates, where different initial conditions
| generate potentially distant outcomes. The number of "rainy
| outcomes" defines the probability of rain, and doesn't
| necessarily get updated with real conditions.
| hazbot wrote:
| This is probably because of either poor sensor coverage, or a
| stale (old) forecast. Many weather services do not issue
| 'nowcasts' that constantly update with the latest weather
| observations (it's a hard and interesting problem), but rather
| a single forecast say 4x a day as the latest Numerical Weather
| Prediction model run comes in.
|
| Fwiw, I agree with your bemusement and scorn - it's not good
| enough! (I say this as someone who has had roles where I issued
| these 'always stale' forecasts)
| jrockway wrote:
| People seem to have different opinions on how good forecasts are.
| I think it likely depends on which model your forecast source of
| choice pulls from. I notice that the weather on my Apple Watch
| corresponds exactly to what GFS says. GFS is OK for medium range,
| but I don't find it too useful for shorter range. NAM is better
| for a day or two out. HRRR is better for a few hours out.
|
| Rather than letting some aggregator simplify the weather for you,
| you can just look at the raw data yourself:
| https://weather.cod.edu/forecast/
|
| For big events, the media briefings by the National Weather
| Service are good resources. But they often stop the briefings
| early; a few weeks ago we had a high probability of a large
| amount of snowfall. The updates stopped at like 9AM, the snow was
| forecast to start around 1PM. Watching the short term models
| showed that the probability for snow was decreasing (NYC was just
| below the snow/rain line), and indeed we got pretty much no snow.
| (It snowed, but it didn't accumulate and the change to rain
| happened early.) To be fair, the briefing from the weather
| service said that the changeover time between snow and rain was
| very uncertain and that it would be the difference between a
| little rain and major snow event. But my point is, you can always
| go get yourself some more data; the closer you get to the event,
| the more accurate the forecast is.
|
| (I don't know if any of you watch Skip Talbot, but he was looking
| at helicity swaths on the HRRR a few hours out, found a big one,
| and where HRRR predicted the strong rotation in the storm is
| pretty much exactly the path of a major tornado. HRRR is never
| going to be perfect, but it is right a lot.)
| rootusrootus wrote:
| That's an interesting point about the Apple weather forecast.
| That correlates pretty well with my experience. It is
| exceptionally inaccurate at short range forecasts. It's kind of
| a running joke at this point.
| herpdyderp wrote:
| The most humorous part to me is when it says it's _currently_
| raining or snowing and it 's clear and sunny. How can a
| system be so wrong that it can't tell the _current state_ of
| the weather?
| bumby wrote:
| From the article:
|
| _> "These observations are then fed into numerical
| prediction models to forecast the weather."_
|
| In other words, the forecasts come from models, not
| necessarily real-time station readings. Those readings are
| inputs into the model, and the models may not get updated
| fast enough to reflect current conditions.
| ako wrote:
| Forecast are usually for a larger area, 5x5 kilometers, or
| 10x10 kilometers. Even within this area, weather will not
| be the same everywhere, so they'll give a probability for
| the entire area.
|
| Windy.com lets you compare different models for a specific
| location, it also includes the size of the area per model:
| https://www.windy.com/?49.339,5.054,5
|
| GFS is area is 22km, ECMWF 9km, ICON-D2 2.2Km, Arome 1.3Km,
| and UKV is 2Km. Even in a 1.3x1.3Km area it may not rain
| everywhere at the same time.
|
| And then there's also the time element, so it's
| 1.3Kmx1.3Kmx1Hrs (or 3Hrs). So lot's of variation possible.
| amarcheschi wrote:
| Yup, a few days ago I made a python script to help me
| choose whether to get to uni by bike or by moped when it
| rains (given two coordinates I calculate the
| angle(bearing?) and checks whether it rains, and the
| angle from which the wind blows to see if I'll get all
| wet in the face) and I had a bit of a hard time figuring
| out why two different providers, windy and
| openweathermap, gave me 2 different wind results.
| Eventually, I found out they were using a different
| model, it took a bit of time tho, because windy only has
| increments of hours, while the other one was more
| granular
| Etheryte wrote:
| I can't even begin to count how many times I've had this
| conversation with Siri.
|
| "Hey Siri, is it going to rain?"
|
| "It doesn't look like it's going to rain today."
|
| "It's raining right now."
|
| "It isn't raining right now."
| lotsofpulp wrote:
| Why would you expect Siri to know if it is raining at
| your specific location? Surely there exists an edge where
| on one side it is raining and on the other it is not
| raining.
|
| So unless you are sitting next to the the weather station
| that Siri is getting data from, I would not expect it to
| know 100% of the time.
| Etheryte wrote:
| I live in the Netherlands. The local weather apps tell me
| when it's going to rain with nearly minute precision,
| along with cloud maps with scrollable time, graphs of how
| heavy the rain will be at what time, etc. It's pure
| nonsense to claim this is a technical limitation when
| other apps do it with ease. No one is expecting it to be
| right 100% of the time, but Apple Weather is wrong about
| rain most of the time, even on a crude scale of say, a
| city.
| ceejayoz wrote:
| > Why would you expect Siri to know if it is raining at
| your specific location?
|
| I don't, but as a result, I expect it not to guess.
| throw0101d wrote:
| > _I can 't even begin to count how many times I've had
| this conversation with Siri._
|
| I live in Toronto, Canada, which stretches about 40km
| east-west, and 20km north-south:
|
| If the west-end (Sherway) gets hit with rain, but the
| east-end is dry, did it rain "in" Toronto when folks in
| Scarborough didn't experience it? Was the forecast wrong?
|
| If it snows in North York but is dry at Billy Bishop, was
| the precipitation forecast "wrong" for one particular
| group of people?
| Etheryte wrote:
| Apple Weather uses your precise location if you allow it
| to, meaning it knows your location down to a meter,
| network and positioning issues etc notwithstanding. It
| doesn't have to guess your weather based on "Toronto", it
| knows your GPS coordinates. There is no technical
| limitation here, as I outlined in a separate comment
| thread [0], other apps already give you weather data and
| predictions with this granularity.
|
| [0] https://news.ycombinator.com/item?id=39683660
| counters wrote:
| Do you want a snarky answer or a serious answer?
|
| The serious answer is that the way you'd try to figure this
| out is by combining weather radar, satellite imagery, and a
| nearby surface observation to try to estimate the current
| conditions. But there can be a latency of up to a few
| minutes from these sources, and they could disagree with
| one another. You have to use them to bootstrap your near-
| term or nowcast product, but enforcing consistency with
| recent real-time and the nowcast is quite hard.
|
| It's a surprisingly nuanced technical challenge. Most of
| the time, it works out just fine (e.g. if there is no
| weather). But people are awfully good at remembering when
| these sorts of analyses end up being wrong!
| jrockway wrote:
| Yeah. Like you would think you could just look at
| reflectivity data to determine whether or not it's
| currently raining, but at most places you are far from a
| radar site and even the 0.5 degree tilt is scanning a
| mile above your head. There might be rain there, but is
| it reaching the ground? All you can really do is guess.
|
| If you're interested in providing on-the-ground condition
| reports, install mPING: https://mping.nssl.noaa.gov/
|
| I keep this app on my homescreen and try to report when
| very light rain starts, since it's not always obvious
| from the reflectivity data. Ultimately the user reports
| get fed into things like improving the model, and more
| data is always good.
| avar wrote:
| Apple devices are constantly phoning home every time they
| see a random AirTag out in the world.
|
| You'd think that if their users are accepting that level
| of communications with the mothership that they could
| ship some AI model to hear rainfall in the wild, and thus
| improve their live weather data.
| counters wrote:
| Surprisingly low signal-to-noise ratio for most of the
| common, creative ways people come up with to detect rain.
| Windshield wipers on cars are another example.
|
| The thing is, even if you did have a super reliable in
| situ "rain detector", how do you combine it with the
| existing datasets like weather radar, which is a gridded
| product? This is actually a really, really difficult
| sensor fusion problem when you then super-impose product
| requirements like the general location real-time
| detection map and the inputs necessary for whatever
| internal nowcasting system they use.
| bee_rider wrote:
| It would be kind of interesting if the app had a "you are
| wrong" button, which allows you to take a picture of the
| outdoors. Apple could either use this to improve their
| models, or even just use it as input data directly if
| they get enough complaints. Plus, it would allow people
| to vent, or it could check if there is something wrong
| with the phone, maybe location is being mis-read or
| something like that.
| tspike wrote:
| It does have that: "report an issue."
| counters wrote:
| There isn't a vector where after-action reports like this
| could "improve the model." That data is useful for
| verification, but these systems generally have no
| learning component to feed the data back into them to
| improve them.
| wiredfool wrote:
| Apple weather quite often has the "expected radar" function
| show storms taking a 90 degree turn right around now, so
| you'll see rain coming from the west, and suddenly when it
| gets to predictions, it's traveling north. (Note, this is
| Ireland). Dark sky was a lot better.
|
| I've also noticed that Met.ie will typically predict more
| rain, and they're usually right. (e.g., last weekend was
| basically rain/drizzle/wind the whole time, met.ie nailed it,
| apple weather said that there would be an hour on Sat and all
| Sunday morning would be wet.
|
| Of course, predicting rain in Ireland is not difficult.
| blaufuchs wrote:
| This one really kills me during Fogust in the Bay Area. I
| wake up and see the sun is gonna break through at ~1pm, oh no
| actually 2pm, oh no actually 3pm... oh no it's just another
| completely overcast day. I can understand missing a day or
| two, but it's bizarre when it happens day after day for weeks
| on end. You'd think the priors would get updated at some
| point.
| SiempreViernes wrote:
| Also useful to keep in mind is that predictions can become more
| accurate without necessarily improving in precision.
| unsignedint wrote:
| I primarily rely on Windy for weather forecasts, which I find
| exceptionally useful due to its ability to compare multiple
| models. The variety of overlays available makes it an
| indispensable tool for all my weather-related needs.
|
| [0]: https://windy.com
| uoaei wrote:
| Same here! Not to be confused with windy.app!
| bamboozled wrote:
| Windy uses some of the models mentioned including GFS, you
| can select the model you want to use. So I'm not sure it
| would be any more accurate than the Apple Watch.
| LeoPanthera wrote:
| Ultra-short-range weather on Apple devices uses what used to be
| called "Dark Sky", before Apple bought it. It's how you get
| those alerts that say things like "Light rain in 17 minutes".
| swores wrote:
| Dark Sky was just the name of a weather app that included
| that feature earlier than Apple's weather app.
|
| But things like "rain in X mins" is a feature multiple
| providers & apps have (including Apple once they bought Dark
| Sky), it's not specifically what Dark Sky was nor is it
| exclusive to them/Apple. (And actually, Dark Sky was probably
| the best weather app all round, yet Apple despite buying them
| and using some of their tech still produce one of the worst
| weather apps in my experience.)
| willmadden wrote:
| Where you live matters more. If you live near a mountain range,
| good luck getting accurate weather predictions.
| ryandrake wrote:
| Our local TV station weatherman has a YouTube channel[1] where
| he geeks out every morning about the weather, providing a much
| more detailed forecast than he has time for during the brief
| windows he has on the TV news. Walks through the HRRR, NAM,
| GFS, satellite pictures, and other sources of information. It's
| a nice compromise if you find the raw data to be overwhelming.
|
| 1: https://www.youtube.com/@markfinanweather
| elil17 wrote:
| Like many other people are commenting, I have subjectively felt
| that rain forecasts have gotten worse. I can think of two
| theories that could explain this. I'd be curious to hear from
| someone more knowledgeable if any of them are right or plausible.
|
| 1. High frequency 5G has thrown off rain forecasts in urban
| areas. Average prediction accuracy has still improved because
| rural/suburban areas don't have high frequency 5G.
|
| 2. The weather app now shows rain forecasts in time blocks as
| small as 15 minutes, even though predictions this granular are
| still inaccurate. This has inflated our expectations for forecast
| accuracy.
| Zamiel_Snawley wrote:
| How does mm wave 5G effect forecasts? Interfering with weather
| radar?
| elil17 wrote:
| 23.8-gigahertz 5G signals can look like water vapor to the
| instruments on weather satellites.
| SiempreViernes wrote:
| I would guess it is mostly down to option 2, coupled with the
| fact that aspects such as precipitation onset are possibly not
| something that actually has improved much: the examples given
| are hurricane tracks and atmospheric pressure which don't
| obviously couple tightly to when it starts raining.
| cogman10 wrote:
| An area has to be extremely densly trafficked before high
| frequency 5G is deployed. And even then, the whole point is to
| minimize broadcast range to avoid interference.
|
| Further, it's only the upper range of high frequency spectrum
| that's being used (not sure who owns it) so it's not even every
| carrier that could interfere.
|
| Finally, the most powerful radars are transmitting in the
| kilowatts range of output. It's hard for me to imagine that the
| microwatt output of cellphones are often the cause of radar
| interference.
| jerf wrote:
| A theory I've been entertaining lately is that the raw
| engineering of the weather forecasts has indeed gotten better,
| but it has been offset by the clickbait-driven need for weather
| forecasts to declare everything to be the Worst Thing Ever,
| Click Here To Not Die. Snow storms that would have in my youth
| been a medium experience hardly worthy of note get their own
| names and days of breathless pre-coverage from the weather
| channels nowadays.
|
| The net is the improved raw accuracy of the weather forecast is
| offset by the difficulty of reversing the clickbait layer
| slathered on top.
| counters wrote:
| (2) is a big ol' bingo. There was a race towards the bottom
| line of higher spatial and time resolution over the past 5
| years (claims along the lines of "higher resolution means
| higher accuracy!"), which led to an awful lot of products that
| are nothing more than naive interpolations of coarser data. So
| couple the perception of "better"/"more accurate" products with
| a wholly insufficient technical approach to realizing this and
| you have a perfect storm for end users to feel that weather
| forecasts are getting worse. They just over-promised and under-
| delivered because many people who entered the field from
| outside of it completely underestimated how hard it is to push
| weather forecasting technology forward.
|
| (1) is irrelevant for weather forecasting.
| brewdad wrote:
| Short-term forecasts (1-2 days) seem more accurate than ever.
| However, weather as a business has meant a race at both ends of
| the forecast spectrum. Apps now offer minute by minute
| forecasts on the one hand or 10 and 15 and even 90 day
| forecasts on the other. Neither of those forecasting models are
| anywhere near ready for prime time but there is a market demand
| for them, so they get put out there anyway.
| Workaccount2 wrote:
| Learning to read radar is phenomenally helpful in determining
| whether or not it will rain. It's not very difficult either.
|
| A few years ago I was able to stop my friend's outdoor wedding
| (on the terrace as opposed to the hall, the venue had both
| ready) from getting rained out by reading the radar and
| catching a small pocket storm that had formed and coming right
| towards us. Sure enough it down poured, but everyone was inside
| for the ceremony. Reading just the weather report, there wasn't
| even rain forecasted.
| goatkey wrote:
| Anyone who lives in a hurricane-prone area like myself (Florida)
| knows that while forecasts have gotten a _lot_ better, there is
| still so much room for improvement.
|
| I am not affiliated, but I recommend checking out
| https://www.forecastadvisor.com/ to see what forecasts are best
| for your city. I totally changed weather providers and it seems
| much better now.
|
| 'The Secret World of Weather: How to Read Signs in Every Cloud,
| Breeze, Hill, Street, Plant, Animal, and Dewdrop' by Gooley is a
| fun read for anyone interested in figuring out weather without a
| forecast (or to supplement).
| AceyMan wrote:
| Obligatory citation, https://en.wikipedia.org/wiki/Weather_rock
| jrockway wrote:
| It also keeps tigers away. I don't see any tigers around
| there, anyway.
| paxys wrote:
| All the stuff mentioned in the article is accurate - better raw
| data, faster computers, smaller grids, better predictive
| algorithms etc. all result in vastly better weather info in
| general today. This also means though that you have to put in
| more effort to get a better result _for yourself_. What algorithm
| is the app using? Does it localize all the way to your
| neighborhood, or your street? How frequently does it update? Is
| your GPS accurate? People generally don 't think about this
| stuff, but some fine tuning can result in vastly better results.
| kylehotchkiss wrote:
| One thing I came to appreciate about growing up on the east coast
| was how much more accurate the forecasts were than they are in
| Southern California. The winds pushing east, the expansive radar
| coverage over USA that's publicly available, and the commercial
| airlines collecting weather data means the storms and weather
| systems are well understood as they're coming over. Plus the
| storms make nice straight lines from north to south that push
| through. In Southern California the rain forecasts always seem
| off. Even right now, it's raining and the forecast told me it was
| just supposed to be a little cloudy.
| chasd00 wrote:
| the forecast for Southern California can just be a standing
| Sunny and 85F. The days it's wrong are infrequent enough to be
| tolerable. I didn't think that area even had meteorologists.
| antod wrote:
| The movie LA Story comes to mind where the TV forecaster
| prerecords their weather reports.
| timetraveller26 wrote:
| okay, nice, but what about software delivery forecasts?
| callalex wrote:
| Dark Sky brought a lot of this powerful forecasting to a hyper-
| local level. It's such a shame that Apple bought it up and
| just...threw it all away. What a waste.
| counters wrote:
| Dark Sky didn't have "powerful forecasting." They literally
| just had a simple computer vision app which used optical flow
| to track blobs and weather radar, and then they extrapolated
| those blobs forward.
| brewdad wrote:
| It was a tool that was either very accurate or inaccurate
| depending on your perspective. If DS said rain would be
| starting in 8 minutes, it almost always rained at my house
| very soon thereafter. Very accurate. However, sometimes that
| rain came 4 minutes later or perhaps 12 minutes later. Now
| the forecast was off by a factor of 50%. Could be no big deal
| or a thing that ruins your morning depending on whether you
| got caught out in it and expected to by dry or not.
| counters wrote:
| Well, tracking a rain blob on radar that is 8 minutes from
| your house is an extraordinarily linear problem, so not
| surprising they'd have absurdly high P/R for that forecast
| :)
| LeoPanthera wrote:
| If by "threw it all away" you mean "integrated into the built-
| in weather app on every Apple platform" then, sure. I guess.
| jdminhbg wrote:
| Apple even opened it up as an API that's cheaper than lots of
| the others! I don't know where people get this idea that DS
| died, it's like they just took what happens to lots of other
| startup acquisitions and extrapolate it like it's a blob of
| precipitation moving towards their current location.
| glitchinc wrote:
| I could not disagree more.
|
| I paid far less attention to weather forecasts 30 years ago than
| I do now, but I have numerous anecdotal examples of how weather
| forecasting models and information provided by publicly available
| weather services have trended towards uselessness.
|
| There is no publicly accessible weather information service that
| can accurately forecast weather at my house. One of the first
| purchases I made when I moved in to the house was an Ambient
| Weather Station resulting from pure curiosity that has evolved
| into an interest in keeping a historical record of "actual
| weather". Daily hi/low temperatures generally have positive
| correlation with forecasted temperatures, but the spread between
| forecasted temperatures and actual temperatures is generally ten
| degrees less than forecasted.
|
| Long term qualitative temperature trends ("above average for the
| winter" and similar) are positively correlated.
|
| But ...
|
| - Forecasted storm intensities are wildly inaccurate. Forecasted
| high-intensity rain storms end up being all-day drizzle events or
| on and off rain showers, and visa versa. A forecast of "a passing
| afternoon shower" ends up being an all-day wash-out.
|
| - Precipitation forecasts are wildly inaccurate, without
| correlation. Actual precipitation can be far less than forecasted
| or far more than forecasted, even when compared to short term
| forecasts--to include same day and intrahour forecasts. Just this
| past weekend we had accumulating whiteout snow squalls on an off
| all day long on Sunday, yet there was never any mention of any
| possibility of snow by any local meteorologists or by any weather
| forecasting service I routinely check.
|
| Dark Sky was the best app I ever used for weather forecasting.
| Its short and long term forecasts were more than sufficient for
| planning purposes, but where the app to this day has had no equal
| was in its intrahour local forecasts and precipitation forecasts.
| If Dark Sky alerted me that there was going to be tornado in my
| area within the next 15 minutes, I saw a funnel cloud 15 minutes
| later. If Dark Sky alerted me that it was going to stop snowing
| in 15 minutes, the snow stopped 15 minutes later. Sadly, Apple
| lobotomized the service when they claimed to have integrated Dark
| Sky functionality in to Apple Weather. Even though I fairly
| regularly report weather accuracy issues to Apple via the Weather
| app, the reporting and forecasting provided by Apple Weather has
| never improved.
|
| - Seasonal precipitation forecasts are wildly inaccurate without
| correlation. Modeling (from NOAA, local meteorologists, etc.)
| suggested we were to have "above average snowfall" this winter,
| with the official average winter snowfall being 48 inches. We
| have received 20 inches so far this winter. Either winter will go
| out with a bang in the next few weeks (which would be nice, IMO),
| or modeling will have predicted more than 140% of the actual
| snowfall. This is an altogether unfair comparison, but why not:
| if the executives of a publicly traded company forecasted 140%
| more revenue to shareholders than the company they preside over
| realized, they would all be immediately fired, sued, jailed, etc.
|
| If society collectively will not tolerate 140% inaccuracy in
| financial matters (stock price manipulation, value destruction,
| and so forth), should we be content with weather forecasting and
| modeling that is just as inaccurate? After all, weather is
| treated as (only) a financial matter by insurance companies. On
| an individual level, viewing weather's impact through financial
| optics still makes sense--from lost days of work and lost wages,
| to insurance premiums, to food prices, to transportation costs,
| to taxes, to paying for the ability to get your money back for a
| concert ticket you bought months ago if the weather is too bad.
|
| Climate change is certainly wreaking havoc on weather modeling,
| but it has been doing so for a significant period of time and the
| models do not appear (to me) to be getting better at adequately
| accounting for the effects of climate change. If current weather
| forecasting models cannot be adapted to accurately account for
| the effects of climate change, it may be time to either
| fundamentally change the way weather modeling and forecasting is
| done, or not do it at all. Taking out my broad brush and bucket
| of paint: are there any companies relying on AI to develop a more
| accurate weather forecasting service?
|
| And if anyone has a weather service to recommend that will not
| "Night at the Roxbury" me with ads and that has accurate 3-day-
| or-less weather forecasts, I am all ears. Please post them here.
| counters wrote:
| Climate change has no impact on weather modeling. The vast
| majority of weather forecasts derive from physically-based
| simulations of the atmosphere; the physics of the atmosphere
| don't suddenly change because the climate is warming. However,
| we rely equally heavily on statistically post-processing these
| physically-based simulations to correct systematic biases and
| better contextualize their outputs. Drift in the distribution
| of weather conditions - even small - can contaminate some of
| these types of applications. But not really in a way that you
| can honestly claim "climate change is making weather forecasts
| less accurate."
|
| > are there any companies relying on AI to develop a more
| accurate weather forecasting service?
|
| Sure there are. But AI isn't a silver bullet, and existing
| weather forecasting technologies are _really freaking good_.
| For all of the hullabaloo over AI-NWP systems like Google's
| GraphCast and Huawei's PanguWeather, these state-of-the-art
| systems are about _on par_ with the best-in-class existing
| numerical weather models; they offer incremental improvements
| in tuned forecast accuracy, but these improvements are
| statistical descriptions of a very, very large number of
| forecasts - end users really wouldn't see any practical
| difference in forecast quality if they relied on these
| forecasts. But to my point above - even AI-NWP outputs would be
| filtered through statistical post-processing to boost their
| accuracy/utility.
|
| There are a lot of companies that _claim_ they use AI at
| different parts of the weather value chain to improve
| forecasts. A lot of them stretch the truth as to what extent
| they really use AI or ML. The simple reality is that the
| weather community has used ML since the 1970's to improve
| weather forecasts.
| toolslive wrote:
| But it's still a chaotic system and Lyapunov would claim we're
| quite vain to even try.
| Workaccount2 wrote:
| Keep in mind, weather forecasting is something that is
| exceedingly difficult and that concerns just about everyone. That
| means it is particularly ripe for confirmation bias.
|
| We objectively know that weather forecasts are more accurate than
| ever. We subjectively know that they are bad/gotten worse,
| because last Thursday I brought my umbrella to work for nothing.
| vanilla_nut wrote:
| I find that 4 to 7 day forecasts tend to be 80% accurate. So
| probably a little bit better than they were when I was a kid.
|
| Unfortunately, the most important part of any forecast IMO is
| intensity. I don't care if we're going to get snow flurries all
| day, but if we're going to get a foot of snow, I would like to
| know -- and not just when the winter storm warning goes into
| effect!
|
| Similarly, I don't care if we're going to get scattered showers
| all day. But if we're going to get a downpour in the afternoon,
| I'd like to know so I can avoid getting caught in a flash flood
| on a trail or on the road.
|
| Same thing applies with temperature: if it's going to be cold all
| day, good to know. But if a rainstorm is going to remain active
| during a deep freeze and create a layer of ice on every exposed
| surface, I need to be prepared for walking, biking, or driving.
|
| Fortunately there's a somewhat local weather station near me that
| provides an RSS feed of longform weather forecasts. But I notice
| that more and more people wind up surprised by slightly-abnormal
| weather events as they rely more and more on smartphone weather
| apps. Weather apps that utterly lack the nuance that a paragraph
| of text can provide.
| mikeortman wrote:
| This speaks on long term outlooks at synoptic scale, we really
| should put some energy on researching mesoscale long term
| outlooks, or even 4 hour short term. It's a difficult problem to
| solve as the variables are quite complex, but the reward can be
| substantial -- on-land severe weather impacts less people but
| often is deadlier and can cause huge financial loss in areas that
| may not expect it.
| qwertox wrote:
| I once listened to a podcast [0] with interviews of a couple of
| scientists at the ECMWF (European Center for Medium-Range Weather
| Forecasts).
|
| I think it was in that episode where one said that every 10 years
| we improve the forecast by 1 day.
|
| It was recorded in 2019, so AI wasn't really that much of a topic
| as it is today, considering that Google published an AI weather
| model in November of last year [1].
|
| [0] https://omegataupodcast.net/326-weather-forecasting-at-
| the-e...
|
| [1] https://deepmind.google/discover/blog/graphcast-ai-model-
| for...
| bilsbie wrote:
| I can't believe they killed dark sky. That was accurate to the
| minute. Incredible.
| jrmg wrote:
| I remember reading in _The Signal and The Noise_ * that people
| _think_ that forecasts are bad if it rains, but the chance of
| rain was reported as below 50%. Getting rain when the forecast
| told you there would probably not be rain is annoying; getting a
| sunny day when the forecast predicted likely rain is a pleasant
| surprise.
|
| To get what people judge to be a 'good forecast', the chance of
| rain has to be adjusted to be wildly too high - so that's what
| consumer-focused forecasters do.
|
| * https://en.wikipedia.org/wiki/The_Signal_and_the_Noise
| HankB99 wrote:
| > the chance of rain was reported as below 50%.
|
| I've come to think of that as "it is going to rain 50% of the
| time. I don't know if that's what really is meant by "50%
| chance of rain," but it seems to fit.
|
| And overall I tend to believe that the forecast is
| astonishingly accurate. This is in the Midwest (Chicago market)
| where weather has to cross large portions of the country or
| Canada before it gets to us. I suppose there are areas on the
| coast where weather is more volatile and harder to predict.
| luplex wrote:
| I think it means "for any given point in the specified area,
| and for any given point in time, p(rain)=50%
|
| So it of course won't rain for exactly 50% of the time on a
| given day, but over the long run, it will.
| bombcar wrote:
| My experience is that about 50% is where "rain will happen
| somewhere nearby, it may affect me".
| nektro wrote:
| "50% chance of rain" means that there's 100% chance of rain
| for 50% of the area
| kxrm wrote:
| Chance of rain is defined by NWS as:
|
| "The probability of precipitation (POP), is defined as the
| likelihood of occurrence (expressed as a percent) of a
| measurable amount of liquid precipitation (or the water
| equivalent of frozen precipitation) during a specified period
| of time at any given point in the forecast area. Measurable
| precipitation is equal to or greater than 0.01 inches. Unless
| specified otherwise, the time period is normally 12 hours.
| NWS forecasts use such categorical terms as occasional,
| intermittent, or periods of to describe a precipitation event
| that has a high probability of occurrence (80%+), but is
| expected to be of an "on and off" nature."
|
| Source: https://www.weather.gov/bgm/forecast_terms
| avar wrote:
| Here in the Netherlands everyone mostly uses short-term live
| radar tracking of rain clouds and precipitation over actual
| predictive weather forecasting.
|
| In an urbanized area most "is it going to rain?" questions are
| short-term, e.g. is now or 30 minutes later a good time to bike
| home?
|
| Perhaps this wouldn't be as useful in other areas. The
| Netherlands gets very spotty rain. So even if you've got a 100%
| chance today it's probably 1-2 hours spread throughout the day,
| and sometimes very heavy rain followed by a dry spell.
|
| The only time I've seen it to be incorrect is if a moving rain
| cloud just barely misses you due to changes in wind patterns.
| moritzwarhier wrote:
| Same here from Germany.
|
| Never really thought about it, but I've opened the "Rain
| radar" more frequently than any weather app including the
| native one during the last couple of years, too.
| bee_rider wrote:
| I sometimes wonder if people think forecasts are bad because
| they think of it in terms of: there are two possibilities, the
| forecast will be wrong, or it won't. Therefore, the weatherman
| should be right at least half the time.
|
| Of course, there are countless ways for the for the forecast to
| be wrong, and only a couple ways for the forecast to be right!
| kirrent wrote:
| Amusingly he was unwittingly writing about his own future.
| People still make fun of Silver for Trump's win in 2016 because
| 538's final prediction of about 30% likelihood for Trump was
| 'wrong'.
| JoeAltmaier wrote:
| Twelve year old won the San Jose Mercury News weather prediction
| contest one year, by predicting each day that the weather would
| be the same as the weather the day before.
|
| Consumer weather prediction isn't about being right. It's about
| pleasing the customer by appearing to be helpful. Which often
| means exaggerating the chances of abnormal weather, so if it
| happens you can be a hero.
|
| Real prediction is boring.
| hazbot wrote:
| Depends, the "optimal" forecast can be very sensitive to the
| scoring metrics used.
|
| E.g. Darwin in Australia's tropics - persistence forecasting
| (as you describe above, just predicting the weather the day
| before) does very well on a metric like 'mean absolute error'.
| But has no practical skill at forecasting a severe tropical
| cyclone (aka hurricane/typhoon)! Many are willing to accept
| _some_ level of false positives and a higher mean absolute
| error, because the cost of a surprise cyclone is so
| devestating.
| ImaCake wrote:
| This would work in San Jose because it's a hot Mediterranean
| climate. Such climates have very predictable hot dry summers
| and cool wet winters. In Perth, similar climate, we often go
| month's without rain in summer but will have several
| consecutive days of rain in winter.
|
| I imagine using the previous day would have a much lower skill
| score in more variable climes.
| Vagantem wrote:
| Interesting! As a contrast, I'm using historic weather data to
| predict future weather - couples use my free wedding weather
| predictor to find the perfect date for their wedding:
| https://dropory.com/
| hazbot wrote:
| Cool! If you end up wanting to expand beyond just the nearest
| weather station (forgive me if I've misunderstood your
| process), you could look into ERA5 - free Numerical Weather
| Prediction 'reanalysis' of past weather on a regular grid.
| openmeteo has some open source tools for extracting time series
| data from it.
|
| But, although you get good spatial coverage, the drawback is
| 'the map is not the territory' - the model's representarion of
| reality doesn't perfectly mesh with the weather on the ground.
| ufocia wrote:
| A more catchy title would've been "Weather has become more
| predictable".
| egl2021 wrote:
| Geezer alert: forecasts look amazingly good to me. When I was a
| kid in the Pacific Northwest, it was routine to miss major storms
| until they hit land. We didn't have satellites, oceanic buoys,
| etc., and I remember the TV weather guy saying things like "we've
| had a report from a ship at sea..." and proceeding to make wild
| guesses.
| nvahalik wrote:
| This might be true for some areas but maybe not for others. Where
| we live is on the very edge of the NWS coverage. Our forecasts
| and messaging is generally a lot more "loose" than folks closer
| to the main NWS "office".
|
| I am not sure if this has to do with radar capability but all the
| old time hams seem to corroborate this.
| cameronh90 wrote:
| The weather forecasts in the UK are definitely much better than
| they were a decade ago, especially in the 3 to 14 day range.
| However, I still find my stupid heuristic works quite well for
| predicting tomorrow's weather: the weather tomorrow will be the
| same as what it was today. The UK often gets sticky ("blocking")
| weather patterns, so it works surprisingly well.
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