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Windy.com

windy.com

1,052 pointskaycebasques212 comments

Windy is great. The map is appealing, but be sure to check out the forecast view for a particular location. Also make sure you try different locations. I'm in the Salish Sea on Orcas Island in the San Juans and because we have a lot of topography here mixed with ocean, we have a lot of local effects, contour winds and so on and there are big differences between locations.

Also note that Windy can get it wrong. I grew up in Cape Town and forecasting there is easy compared to here because it's the tip of Africa surrounded by Atlantic and Indian Ocean. Here it's very mixed with land, sea, big 11,000ft mountain ranges like the Olympics and so on and this region is hard to forecast. For where we are, the forecasts - and Windy's map specifically - is wrong fairly often.

A trick that a lot of folks don't know about is using ATIS, AWOS or ASOS at a local airport or airfield. If you want to know what the weather is at a given location, find a nearby airport, get their ATIS (or AWOS or ASOS) phone number and you can call and get a real-time report that is extremely accurate. I do this for KORS, our local airfield all the time. You can get this data off Foreflight although I'm sure there are plenty of free alternatives. Obviously it's current weather, not forecast, but it's often helpful.

You live in a beautiful area. I grew up scouting around there...on one trip we were invited to embark & leave Eastsound earlier than anticipated because a couple of our members decided to "casually" lift some cigars from a store there (IIRC). xD Thanks for the ATIS info too. I wonder if it's the same type of message I hear on non-noaa VHF from nearby.

Thanks - I'd forgotten about the marine VHF reports. Rarely listen to them, and I should. LOL! Trust me Orcas has plenty of scandal that's worse than that. I'm sure less than half the island has all your social security numbers memorized.

If you're in the US, you can get METARs from aviationweather.gov:

https://www.aviationweather.gov/metar/data?ids=KSEA&format=d...

The forecasts for the US at forecast.weather.gov are really good too. I constantly refer to the hourly precipitation charts to figure out how much rain gear I should hike with, and their temperature predictions are useful too. Plus if they have any warnings or watches it’s helpful. It’s much better than any of the paid services out there.

Also worth mentioning that Windy provides several different forecast models that you can choose between. There are high resolution models like NAM, and lower resolution models like GFS - toggling between them often gives me a better sense of what to expect.

Agreed. It was interesting to see the deltas between the models for Hurricane IRA. Was significant 3 days out.

When you say Windy can get it wrong, isn't it really the underlying forecast models that are wrong?

It's unclear to me if Windy is doing much more than creating a great presentation of existing data. Their website does list an open ML role, though..

I wonder how much rolling your own weather forecast is tantamount to rolling your own crypto??

By default, Windy uses the ECMWF weather model. You can also change it to GFS or ICON, which many american forecast websites use.

ECMWF, GFS and ICON are made by national/international forecasting agencies. IBM also has its own proprietary weather forecasting service, notably used by The Weather Channel. Other apps mostly use one of these models or aggregate predictions from different services (e.g. AccuWeather claims to aggregate many different models, including those from national agencies around the world)

for people who live in europe, try AROME, it's very limited compared to the other models, but it does (IMO) give the best forecast.

in my experience AROME tends to forecast on the drier side of the weather. Since I'm in the UK I use AROME first and flick between ECMWF. (ECMWF tends to forecast on the wetter side!!)

for the next hour(s) forcast, I tend to use rain radar - windy has this, but it's not the best I use netweather.tv (there's many others though)

I'll add in a vote for the UK Met Office here too (particularly for the UK). AROME is a high resolution 'nested' model, where the region of interest is simulated at a higher resolution that the (often global) driving model. Similar to ICON-D2 (Germany [0])and UKV (UK [1]). These will typically produce a better downscale of the forecast to a local area.

Their utility depends a bit on what is causing the uncertainty in the forecast though. For the mid-latitutdes, a lot of the uncertainty comes from timing the arrival of a weather system. In these cases, the high resolution simulation doesn't help you, as it just incorporates the uncertainties of the lower resolution driving model.

The ensemble simulations that the weather servies perform will help you there, ECMWF has a really nice meteogram for individual locations [2].

[0] - https://www.dwd.de/EN/ourservices/nwp_forecast_data/nwp_fore...

[1] - https://www.metoffice.gov.uk/research/approach/modelling-sys...

[2] - https://apps.ecmwf.int/webapps/opencharts/products/openchart...

I would love to see the UK Met Office model in Windy

I don't know why it's not there - I'm assuming it costs money

> IBM also has its own proprietary weather forecasting service, notably used by The Weather Channel.

Is it not the case that IBM bought the weather channel to acquire the technology with no interest in the WC business?

IBM bought The Weather Company, which was the holding company of The Weather Channel. The forecasting technology is now owned by IBM, which licenses the weather data to The Weather Channel.

Rolling your own weather forecast is more akin to rolling your own election forecast (ahem).

Equally dangerous, but not designed to be private and a huge different set of risks.

Political motive to change weather forecasts, and weather motive to change political forecasts.

Very dangerous.

depends what you mean by 'rolling your own weather forecast'. If by that you mean you're going to do some statistical modelling on ensemble data, you're going to get a much better idea of what is likely to happen than you can from the average datasets you get on sites like windy

Another option is the point forecast from weather.gov. For example, here's the forecast for Eastsound: https://forecast.weather.gov/MapClick.php?lat=48.6968&lon=-1...

"Also note that Windy can get it wrong."

I kind of lost trust in it, when I was in the middle of a thunderstorm, yet windy showed me all sunny.

Granted, it was in the alps and forcasting there is hard, but it was the current state of things they got wrong.

Convective ("heat") thunderstorms are pretty much impossible to forecast precisely. On the day of, I'd recommend to use the radar, satellite and wind measurement, to get a picture what's happening, not the forecast anymore.

"Use the radar, satellite and wind measurement"

I did. And they showed me no clouds, rain or wind worth mentioning.

If you were in the storm.and the radar didn't show anhthing maybe the radar was out of service in that area, which is very unusual.

It's not realtime, some of the underlying models only get updated every 6 hours.

Another thing to consider is the difference between a global scale forecast mode (GFS, ECMWF) and a mesoscale model (HRRR, NAM, RAP). The later uses a much smaller grid size and can take into account terrain. In a place the the San Juan's (and the PNW in general), a lot of the weather patterns are coastal terrain driven so these models can be much more accurate. They catch is, they don't see out of far due to their higher computational complexity.

Here is a great resource to read up on the various models (there are far more than Windy offers): https://luckgrib.com/models/

I live a couple islands over from you. As a frequent sailor, I use Windy regularly before a race, but it's never completely accurate (PredictWind tends to be better). Great for looking at general trends and visualizing patterns. This area is tricky — lots of microclimates for the reasons you mentioned and it's almost impossible for a service like Windy to be completely accurate.

You can also get the METAR (observations updated hourly) from the Aviation Weather Center: https://aviationweather.gov/metar/data?ids=KORS&format=decod...

I live less than 3 miles from an airport, but due to microclimates the weather is completely different. The NOAA does a reasonable job of forecasting my specific area, but most weather apps will take the current conditions from the airport, which can be off by over 10F in temperature alone.

> , find a nearby airport, get their ATIS (or AWOS or ASOS) phone number and you can call and get a real-time report. Obviously it's current weather, not forecast, but it's often helpful.

The US Government makes both METARs (current report) and TAFs (area forecast) available online. You can also get PIREPs (pilot reports) if you are interested in the conditions in the air.

Along with free APIs! (XML, though.)

https://www.aviationweather.gov/dataserver

that’s neat! thanks for mentioning it.

I use an Android weather widget called Meteogram Pro. It supports pulling in and displaying METAR data, among a thousand other options.

You can make plots of things like thunderstorm probability, thickness and altitude of different cloud layers, azimuth and elevation for all planets in the solar system, pollen index, tide height, you name it.

Can you let me know which developer it is? There are a few with the almost exact same names. Thanks!

https://play.google.com/store/apps/details?id=com.cloud3squa...

There's also a non pro version, but I'm not clear on the differences because I still have a decade or more worth of the old system credits bought to support what's always been a great app/widget.

"If you want to know what the weather is at a given location, find a nearby airport, get their ATIS (or AWOS or ASOS) phone number and you can call and get a real-time report that is extremely accurate."

To get the phone number:

     curl -Ls https://www.airnav.com/airports/get?s="$1"|sed -n '/<TR>.*WX/{s/.*=right>//;s/&nbsp;.*top>//;s/<.*//p;}'"

For example, Orcas Island

     curl -Ls https://www.airnav.com/airports/get?s=orcas|sed -n '/<TR>.*WX/{s/.*=right>//;s/&nbsp;.*top>//;s/<.*//p;}'

or, without the redirect

     curl -s https://www.airnav.com/airports/KORS|sed -n '/<TR.*WX/{s/.*=right>//;s/&nbsp;.*top>//;s/<.*//p;}'

1000% agree! I sail and Windy is great for an idea of what is going to happen, but no substitute for what is actually happening on the water, i.e., the fine-tuned weather that is necessary to sail a boat. If you want to know a hurricane is coming or the potential for a "weather event," then Windy is truly your friend. Otherwise, what the OP wrote is totally necessary. For sailing, you want to look at lighthouse weather data (e.g., NOAA) and the numerous buoy systems (e.g., https://buoybay.noaa.gov/) really are your friend.

> Windy is great.

I don't like the zooming ratio

The forecast that worked best for me (at least in summer in Europe) was local sailplane text forecast from the respective national service. It was an interpretation of the model by a very experienced human with a big picture introduction ("this front" or that "high pressure area") and also expressed uncertainties. They are sometimes behind soft paywalls, though (need to register, but its free. There are some weird rules of the EU about some weather data - cannot be freely available. I don't get it)

If you're in the Pacific Northwest, specifically Washington/Western Washington, then UW's weather models reach much higher spatial resolution than Windy appears to do.

https://a.atmos.washington.edu/mm5rt/

I recommend starting with the 4km or 1.3km WRF-GFS model and looking at something like 3hr Precip.

Windy also has HRRR (among others) for hi res near term domestic US incorporating radar.

https://windy.app/features/hrrr-weather-forecast-model.html

Other models:

https://windy.app/guide/windy-app-weather-forecast-models.ht...

over the past few years my use of weather apps + forecasting has really been improved by reading alongside them the local NWS office's "area forecast discussion"which is published multiple times a day by the station's meteorologists: https://www.wrh.noaa.gov/total_forecast/getprod.php?new&wfo=...

It's really great to be able to contextualize the state of a Windy map, for example especially in Seattle where the weather patterns are tightly influenced by the Olympic mountains and other local conditions which these global maps usually fail to capture or express well.

Windy is impressive stuff but looking is half the battle with these maps, wind directions and "that weather blob is orange right now" only really go so far when your weather area's geography isn't simple; in fact, i think that the older static Weather Channel style maps which expressed the pressure gradients and fronts better and helped you build a model of what the weather is doing rather than which way the wind is blowing. (see https://s3.us-east-2.amazonaws.com/journeynorth.org/images/g... for an example)

Here's the same for the SF Bay area for those interested (took some poking around to find it, basically MTR is the monterey/bay area weather center so I tweaked the URL params to match)

https://www.wrh.noaa.gov/total_forecast/getprod.php?new&wfo=...

Yup! And in general, you can click your location on https://www.weather.gov/ 's image map, and it'll redirect you to the local office URL which is the same 3 letter code: https://www.weather.gov/mtr/ and there is a link to the AFD in the "Text Product Selector" on the page!

Windy has all of that. A quick glance at the layer menu on the right of the map shows how to toggle that and more.

Can you explain how to find the AFDs in Windy's UI? I'm not able to find it in the layer menu...

Absolutely right about the forecast discussion. I generally refer to that first (and even check it regularly throughout the day for updates). It is a far better tool for understanding the stage of the weather.

The other favorite of mine is the HRRR high-res models. You can see a simulated radar map for the next 48 hours: https://mag.ncep.noaa.gov/model-guidance-model-parameter.php...

Great to see some love for Forecast Discussions! As a pilot, and overall outdoor enthusiast I've relied on Forecast Discussions for many years. If I may be so bold, my app Deep Weather for iOS is designed to be the most convenient and easy-to-read source for Forecast Discussions. It's free (with some more advanced/optional features requiring a subscription): https://apps.apple.com/us/app/deep-weather/id528748182

Not available in Europe! Too bad

Yes I'm sorry, Area Forecast Discussions are a product of NOAA/National Weather Service in the United States and its territories. They do cover a lot of ground from Guam to Puerto Rico, the continental US and Alaska, but not Europe.

That’s not really a reason to restrict its installation to users that have a US iCloud account only. People travel, move, or have interests in other areas than their home country.

“Straight from the experts at NOAA”... but through a platform/app not affiliated with them in any way.

I find apps that use that kind of marketing to make it sound like they are associated with the big agency they yank the data from to be really sleazy.

I don’t see the problem - I didn’t read it as “we have NOAA experts working for us” but as “we are sharing data from the experts at…”. I think sleazy is… unkind - especially reaching that conclusion from just one line in a description.

nice app! I seem to have gotten myself stuck, though. In weather graphics I opened up day 4 fronts and now I can zoom around on it but there is no way to close it and the rest of the app is blocked!

Anyway, just a small bug report. Thanks for the app, useful enough to keep it installed!

Some past threads:

Live View of Hurricane Laura - https://news.ycombinator.com/item?id=24289287 - Aug 2020 (54 comments)

About Windy (2018) - https://news.ycombinator.com/item?id=21701065 - Dec 2019 (34 comments)

Typhoon Lands in Japan – Windy Storm-Tracking Platform - https://news.ycombinator.com/item?id=21232332 - Oct 2019 (44 comments)

How wind and geography influences wildfire smoke - https://news.ycombinator.com/item?id=18416850 - Nov 2018 (6 comments)

Windy.com - https://news.ycombinator.com/item?id=15094639 - Aug 2017 (103 comments)

Even before 2017, I recall reading here about... windy.tv(?) or some sort of odd extension. Shortcut has been in my toolbar, url updated 1 or 2 x's, since. A great resource when travelling by road looking to avoid high winds, rain, sleet & snow.

Windy is fantastic.

But, I'm curious if there are any apps or weather models that give probability distributions? Telling me that it is going to blow 10 mph is useful, but telling me, for example, that there is a 60% chance that there will be a 10 mph wind and a 40% chance that the wind will blow at 15 mph seems more in line with how I would naively assume weather forecasting works.

Right now, the ECMWF [0] model in Windy shows 6 mph winds gusting to 30 mph for my area (SE Alaska, with lots of mountains and fiords, so a area that is gusty and hard to predict by nature). It almost feels like they're throwing their hands up in the air and admitting that they have no idea what the wind will actually do today. Which, is fine, if that's the case.

I just wish consumer weather forecasts did a better job communicating probabilities and uncertainties instead of spitting out a single value.

[0] https://www.ecmwf.int/

ECMWF makes probabilistic forecasts, in the form of an ensemble of 50 IID examples. So this is mostly matter of Windy figuring out how to put that information into their UI.

Thanks for the reply. It sounds like you have a much better grasp of these things than I do.

So, when clients like windy forecast "10 knots east gusting to 20" for ECMWF, do you know if those numbers are directly copied and pasted from the ECMWF model, or do clients take the probabilistic forecast model and make some sort of average prediction that they display?

I'm very interested in how clients like windy go from a probibilistic forecast model to a singular hard number. Unless this is something built-in to ECMWF itself.

GFS takes a simple average of the ensembles for their avg model, I believe. The biggest problem is that you can't use statistics like you normally would in meteorology. Predictions are actually very good for knowing WHAT happens to a weather system, but not WHERE it happens.

I work in the sailing space, so this is what happens there:

A racing offshore sailor would consider a variety of models and ensembles. Then they would consider the various possibilities for the weather systems and fronts (e.g. front crosses your path +/-5% East/West within a +/-3h gap). A sailor would then avoid any possible dangerous situations, and pick a path that on the most number of models gives them an optimal wind.

It is both an art and a science. If you compare the results of sailors who compete in offshore competitions (such as the Vendee globe), where the boats are all constructed in very similar ways, you'll see that the best sailors consistently get good results, and that is based on good meteorology and a good gain to risk ratio for route choice.

That makes a lot of sense. I sail in SE Alaska.

You'd be surprised how many people make their living on the water up here, but their understanding of forecasting seems to amount to "download windy app"!

Anyways, the word ensemble is new vocabulary for me when it comes to forecasting - things are making more sense knowing what an ensemble is.

Ensembles aren't used much outside of competition or serious industry... windy/predictwind/CMAP have usually more than enough weather for the average boater

No argument from me there! But when the forecast completely misses in SE Alaska, or one forecast model displayed in Windy is way different than others, I naturally get curious as to what happened, so have been more interested in the nuts and bolts than is probably practical.

I'm more comfortable on the water knowing terms like ECMFW, myself!

GEFS is the noaa ensemble product. The operational GFS is actually just a single deterministic forecast run.

A lot of private providers roll up different agencies models to provide their own proper ie tart weather model because this is a lot cheaper than running the HPC required for most deterministic models.

The most important thing when checking the weather, especially with apps like windy, is to compare multiple models for your self to see how “stable” the forecasts are that day.

Windy does allow switching between different models, which can be helpful to roughly gauge probability. Definitely not perfect though. And some of the models are consistently inaccurate for specific locations in certain conditions in my experience.

https://en.ilmatieteenlaitos.fi/local-weather/uk/london?fore... shows 50% and 80% confidence interval as well as median for rain and temperature.

Perhaps something like this https://www.meteoblue.com/en/weather/forecast/multimodelense.... If you check the regular forecasts it also has a predictability figure.

If you click on a specific location, at the bottom you can expand the forecast. Instead of "Basic" select "Wind" which will let you see multiple model forecasts. Not exactly a probability but you can do some mental ensembling to see if models agree or not.

https://imgur.com/a/UezBGqZ

MeteoSwiss does this both for temperature and precipitation. Tends to be the app everyone uses here https://www.meteoswiss.admin.ch

They have been my preferred weather source for a few years now. Forecasting is spotty in my area, but they have a feature where you can quickly compare 4 weather models, which tends to give a good overview. They also have my favorite android widget.

> but they have a feature where you can quickly compare 4 weather models

meteoblue.com offers 18 models if you click on 'MultiModel'. I found them to be very reliable.

windy.com is cool though, respect to the Czech founder https://en.wikipedia.org/wiki/Ivo_Luka%C4%8Dovi%C4%8D

+1 for meteoblue.

I have been using the similar site https://www.ventusky.com for a few years now.

They look like clones.

What's the difference?

There are a LOT of weather geeks around the world. Different folks, different origin stories.

Earth.nullschool is the original one.

This is correct and it is open souce software unlike the commercial derivatives, which do add their own value, granted.

Another one: https://www.windfinder.com

Another similar one: https://earth.nullschool.net/

My journey with weather mapping sites went in reverse order from this thread: Years ago when I ran a local weather blog I discovered the Nullschool site, then a few years later VentuSky, then Windy. I don't do the blog anymore but I still rely on Windy for visualizing weather conditions.

There's also https://www.predictwind.com/ which is a (very expensive) commercial service a lot of boat/yacht folks use for planning. I believe they also have some utilities for delivering compressed forecast data over satellite link as well.

PredictWind has free tier that displays something like 6 forecasts on one screen, app or browser. Def my favourite software and it’s kiwi made!

Their premium tier is for automatic routing and can get expensive for budget sailors.

They will sell you an irridium go and distribute data through their own email client but you can get all of that through Sailmail and using the saildocs email GRIB service for less money with a lot more flexibility, also I’m not sure how good their support is for using something like PACTOR over HF which if you are a licensed HAM is always free.

This stuff really only applies to offshore or other low bandwidth connection use cases. When I have decent cell/internet it’s hard to beat windy’s UI.

Shout out for Ventusky. The app is fantastic. Highest value $3 I spend every year.

The UI for Ventusky is much better too.

Windy looks great, I will add it to my daily weather websites.

My primary visual weather site is the National Weather Service Enhanced Data Display.

https://preview.weather.gov/edd

It's been "*Experimental*" for several years, and the site looks kind of dated, but it provides a useful visualization of radar, satellite, tropical storms, etc, plus it runs on my old PC! =)

I also like the NWS Hourly Graph to give a better idea of for example when it's going to start or stop raining or go below freezing on a given day.

This is the forecast page for my area:

https://forecast.weather.gov/MapClick.php?lat=43.7445&lon=-7...

Put in your own zip code, or type in town and state (sorry, just US). Then click "Hourly Weather Forecast" below the daily descriptions to get this:

https://forecast.weather.gov/MapClick.php?lat=43.7445&lon=-7...

There's no location picker on that page though.

https://earth.nullschool.net/

better than windy, ventusky and what have you

Off topic: I am interested in off-shore solar resources.

Are there raw historic datasets or nice visualization for solar irradiation including over seas and oceans ?

You may be interested in era5 data for historical reanalysis. This is published by the ECMWF and is available for free. I’m pretty sure it has solar irradiance data but I’m not certain. You can also get NCAR reanalysis and other model reanalysis products through the NWS[2].

For visualizing gridded data products you can use panoply[3]. If you just care about GRIBS zyGrib works pretty well too.

[1]https://www.ecmwf.int/en/forecasts/datasets/reanalysis-datas... [2]https://www.ready.noaa.gov/archives.php [3]https://www.giss.nasa.gov/tools/panoply/

There is a startup in Norway called Glint Solar that may help. They serve the floating solar industry with geospatial tools and data, both on reservoirs and offshore. If you can expand a bit on your questions, there may be more resources to point to.

Currently interested in year-round solar irradiation data for seas and oceans (mostly over shipping lanes)

It seems that out to sea (over 100 km from shore) solar actually weakens due to humidity/clouds?

The ocean waves and ocean currents features are so cool! And this thing shows an aurora map! Thanks for sharing.

Other than the canonical "Do I bring an umbrella?" we have one actionable need for precise weather forecasting:

In hot weather I have outfit our California house with an assortment of commercial (quiet whole-house exhaust) and homebuilt (computer fan arrays in each window) fans. We rarely use air conditioning even in extreme heat, instead waiting till outdoor air is cooler than inside air to open up the house overnight. It's important to hang box fans between rooms to stir the air as much as possible; one is storing coolth in the walls. People are always surprised we're not on AC when they come inside the next afternoon.

As we're both on east coast schedules I sometimes have to set an alarm to get up and open up the house. This is guesswork. Better forecasting would really help. I don't see any multimodel tools in any of these paid apps that give me a better view, zooming in on this precise question, than a generic hourly forecast by the usual suspects.

(New construction near us forces a reliance on AC. One would think that in regions with good daily temperature swings, designing a house like a water-cooled computer would make sense. We should be seeing as many rooftop radiators as solar panels. Not a thing...)

Outdoor sports is a big one. For kite and wind surfing, you want a lot of wind, for sailing moderate winds and for golf or wakeboard you want no wind.

Isn't a rooftop water-cooling radiator just a swamp cooler? Common in dry climates.

I occasionally meditated for a bit upon a similar map on Yandex Weather—finally understood what the deal with Siberia is. Like, in spring it's way below zero around Mongolia, while it's on the same latitude as Black Sea where it can already be +20°C. Well, turns out I can clearly see warm air moving from the Atlantic eastwards—until it hits the Urals and stops, and everything beyond that is frozen tundra. Warm air from the Pacific somehow barely reaches Siberia, deciding to turn east or west instead.

Really nice to just watch this on the screen in realtime.

Also in the rain map, it's fun to look at huge clouds spanning entire Europe. Especially if my city is precisely in a small window of clear skies amid the rains.

Since the map is using OpenStreetMap data it would be nice if it were attributed correctly: https://www.openstreetmap.org/copyright

It's there in the bottom right corner.

windy.com is great for forecasts, but you have to be careful of the model used for certain sports. (For example, the NAM model can be more accurate for low wind gusts.)

In my spare time over the last couple weeks I've been building a PWA for paramotor pilots to better visualize winds aloft: https://ppg.report.

Wind modeling - especially for aviation - is really an interesting subject. The main API I use at ppg.report is https://rucsoundings.noaa.gov/, lots fun to learn about (CIN, CAPE, the historical "soundings" manually reported from aircraft and balloons, versus the modern ones automatically pulling data from commercial flights.)

I also really like https://earth.nullschool.net/#current/ It's not so useful as a forecast, but you can move around the world and see everything so well. Take a look at the winds in the Southern Ocean for example, and you can see why it's so tough to sail there.

In the future, I really look forward to owning a globe that shows time-lapse clouds in very high resolution.

I don't see a reason why this cannot already exist.

They are running an impressive show all around, check out their webcam embeds and API, great for spotting fires and things, plus they have their own online community forum. Their mobile app is really good too, includes offline map capabilities, and I take it on hikes for tracking.

The wind animation doesn't work at all for me in Firefox (on Linux, version 91). I see a few large animation "sheets" where the wind is moving in the same direction, depending on where on the map I look. Works in Chromium. Anyone else have this problem?

Screenshot: https://i.imgur.com/eLyQa6X.jpg

Weird. I'm using Firefox 91.0.2 on Ubuntu 20.04 and it works fine. Maybe try opening it in a new empty profile and see if it works?

I did end up getting it to work, left a comment here if you're interested: https://news.ycombinator.com/item?id=28488599

Doesn't work for me on Firefox in Windows either. I've tried a number of things and it seems it just doesn't work on Firefox at all.

Works fine for me in Firefox on Mac.

And for me in Firefox 91.4.0 on Android.

...and for me, FF 92.0, Ubuntu Linux.

Do you happen to be using color management by any chance? Believe it or not (because this does seem insane), disabling full color management fixed the site for me. That is, I changed the setting "gfx.color_management.mode" from 1 (manage all colors) back to 2, the default (which only adjusts the colors of images with tagged color profiles).

It's bonkers, but I think I understand what's happening here, actually. Relatively recently, Firefox started color correcting the content of <canvas> elements. However, some sites will download an image, load it into a canvas created in Javascript, and then use the data for some other purpose.

In particular, Windy downloads a bunch of what appears to be wind data in the form of false color images like [1][2]. Presumably they are using this data to generate the wind animation on the fly in the browser. However, if they're utilizing canvases as part of that process, (my copy of) Firefox is changing the colors out from under them as part of the color management process. Presumably a large enough change in the colors would be enough to break the wind display code completely.

[1] https://ims.windy.com/im/v3.0/forecast/ecmwf-hres/2021091012...

[2] https://i.imgur.com/z3hQKvs.jpg (backup of [1] in case the link dies)

Interesting. It still works for me even with gfx.color_management.mode set to 1. Might be hardware differences or maybe desktop (compositing, etc). I'm using XFCE defaults.

If you don't actually have a profile set, Firefox will (in most cases) treat your screen as sRGB, which means that the colors won't actually be changed.

Wow. Nice find. I also use a canvas to stitch together elevation data encoded as PNGs [1]. Will definitely look into this.

The road to bugs is paved with good intentions.

[1] https://miro.medium.com/max/1024/0*zRx4LGdE_sxxRip7.png

Seems dangerous that color correction would not just happen at the display driver level but would modify the values returned by ctx.getImageData. Good fingerprinting technique though!

I agree, I wish they'd take a different approach.

Have you tried firefox 92?

It works for me on FreeBSD, running "firefox amd64 92.0+build3-0ubuntu0.18.04.1 " in an Ubuntu linux jail.

Could this be a hardware problem? I've been working on a WebGL project and often different graphics cards have different precision from 8 to 16 to 128 bits. I've seen similar quirks when precision truncates calculations.

Edit: Testing different hardware reminds me of the IE5-8 days. Sigh...

https://earth.nullschool.net/

Reminder that weather forecast apps/websites/anything are pretty much all just different UIs for the same underlying global forecasting models. With the NOAA's GFS being the most widely known one. You can find historic forecasts on NOAA's website going decades back.

Not all of them. But many are. It's important to be skeptical of claims made about th novelty and quality of weather forecasts from new/unknown players.

I was paying for it, but didn't renew the subscription, this year in 90 days that I needed forecast was way off in 42 of them, and trying all their different model offers. Maybe next year I will resubscribe, depending how their models forecast over Fall and Winter.

Are you using a different weather app or website that is more accurate?

My understanding is that windy primarily just shows data from different forecast models, so isn't your issue really with the third-party models, not with Windy's weather client?

My grandfather was a meteorologist (taught me forecast based observation and weather station data), and I am also a first officer half of the year (as well have education in modelling for navigation). This year was rough with modelling. I use Windy to validate my forecast and navigation decisions at sea. As we sail, anemometer readings are crosscheck with the forecast from windy and mine, and windy didn't go well. Sometimes paper and pencil do a great job. I started using Windy (windyty.com) in 2016, and until 2020 forecast was quite good, my takeaway is that maybe Climate Change could make the job of weather forecasting much harder.

Huh, fascinating stuff. Do you have any recommended resources for anyone looking to learn more about "paper-and-pencil" forecasting or marine weather forecasting in general?

The weather models themselves are evolving - there was a big upgrade of GFS last year for example

I live north of Sacramento. This summer I found NOAA's GOES-17 satellite imagery to be the easiest and most accurate method in determining where wildfire smoke would move. https://www.star.nesdis.noaa.gov/GOES/sector_band.php?sat=G1...

East CONUS makes it look like Texas has terrible air right now: https://cdn.star.nesdis.noaa.gov/GOES16/ABI/CONUS/GEOCOLOR/2...

Windy has multiple models which is great to check how reliable the forecast is - if they diverge then its a clue. In general, the forecasts are great where there is a lot of good input data, like in western Europe and around the Alps. In eastern europe and on the ocean the forecasts can be way off. This is a risk because the pretty graphics and high time resolution somehow associate with precise forecasts.

Runs very smoothly on Safari on iPhone 6S! An impressive job by the devs.

Awesome. Have actually been looking for precisely this kind of data for potential use in a game that we're currently developing. Thrilled to see what appears to be a solid API too, going to dive right in.

One thing I don't see mentioned, or I may just be unfamiliar with the terminology (and haven't dug much into the docs yet), is how exactly the 'map data' API (ie not the point-location API) works/what format the data is returned in, or if it's more expected to be used as an "embed".

My ideal, based on our current code/implementation thus far, would be to be able to supply a lat/lon coordinate bounding box & have it respond with the data in GeoTIFF format with multiple bands, one for each "data-set".

If anyone at Windy is here & might potentially be interested in discussing our game & the game's use-case for the data, please definitely feel free to reach out -- email in profile. :)

There are already games that use live wind data (see e.g. virtual regatta). They source data directly from NOAA/GFS rather than from an aggregator like windy

I used Windy when planning a bicycle tour. It told me the wind would be mostly from the east, so I began my trip in the east and enjoyed 1300 km with a tailwind.

The same idea could apply to long distance running or hiking, canoeing, and other non-wind sports.

I was really hoping this was https://frida.com/products/windi which is life changing.

I've been using Windy to keep an eye on Hurricane Larry and my friends and relatives in St. John's, Newfoundland. Looks like they're about to be clobbered in a few hours.

I attempted to use Windy to judge surfing conditions on Oahu but the current conditions and forecast are never accurate. They might as well be randomly generated.

I'm surprised that no one has mentioned Windguru.cz yet

Posted previously tens of times.

https://hn.algolia.com/?q=windy.com

I wish weather forecasters would be more upfront about the accuracy of their forecast.

For example "Our rain/no rain 2 day in advance forecast for Seattle was accurate 280 days last year".

If all providers published that, I would be able to get my weather from the best forecaster for my area rather than guessing.

Bonus points if there is a more scientifically rigorous metric to compare by that they all publish.

I was on a HK island when Mankut hit and Windy was incredible. It was much easier to see when what was going to hit than the local news. For the village we were staying, the local news said 12 (noon) was the worst, but it was clear in windy that would be hours later. As this thing did a lot of damage, it was kind of nice to be able to predict it well.

Super cool. Reminds me of https://zoom.earth/ (https://news.ycombinator.com/item?id=23901252) which was really useful recently to gauge wildfire smoke patterns.

I use Windy fairly regularly for military flight planning. Nice tool to get an idea of when to launch to hit a timeline/TOT.

Absolutely love this site for forecasting weather events in my area. Not sure what I would do without it at this point.

Any kite surfers? How have you found Windy for spotting decent places to surf? I’m a fan of Windy but sometimes find it a bit “lowres” in the sense that it does a good job on translating wind direction/force in broader, more general areas while it’s hit and miss for specific spots (eg beaches or nooks). POVs?

The highest resolution model Arome could help but at that level your intuition and experience is essential. BTW The most notable kitesurfer would be the founder and CEO of windy.

What causes this huge plot of very bad air in the middle of Russia near 63.597820342465404, 112.49690168386316?

Looks like there are several active wildfires around the area.

https://firms.modaps.eosdis.nasa.gov/map/#d:2021-09-10..2021...

Right, good catch, thanks!

Random observation: nowhere is 60 degrees F.

I'm looking at San Francisco, as well as Portland and Seattle, all of which the temperature is right around 60. No matter how much I zoom in or out, there are dozens of 59s and 61s, but no 60. Curious why. It can't be coincidence based on how many I looked at.

15C is 59F, 16C is 60.8F so I'd say using integer Celcius and converting to Fahrenheit

My guess is the data is stored in Celsius but displayed in Fahrenheit.

15C = 59F 16C = 60.8F

This is likely due to the source data being vended in whole number increments in degrees Celsius. Converting between Celsius and Fahrenheit using only whole numbers would not allow for 60 to show up (it is between 15 and 16 degrees C, which would convert to 59 and 61). There was a large story around this same issue in the Apple weather app, not showing 69 degrees F prior to iOS 15.

This site has been popular in some aviation sports like paragliding. At least from my casual observations.

I imagine something like this could be a fantastic tool to teach about differential equations and their applications. Just looking at you can see specific hallmarks (sources and sinks), and how that sort of analysis can have super-cool uses.

Does meterology use differential equations to model wind?

yes, but it takes at least a degree to even understand the basics

All of the big agency (NWS, ECMWF, ICON, etc.) use physical models to create the large gridded forecast products. These models work by solving differential equations so your intuition here is spot on!

According to these data Zhytomyr is the most polluted place in Europe... "Zhytomyr is an important economic center in the region. Enterprises in the city include glass, metal fabrication, electronic devices, screens, fabrics, furniture, shoes and others" wikipedia

Asa paragliding pilot/speedflyer, I absolutely love this app/site. We use it all the time!

I use it for surf forecasting. When you click on "waves" icon, the menu extends and there is an icon for a surfer. Click the surfer and not only do you get a different "heat" map but wherever you click will give you the swell for that location.

Windy is popular on Guam. Massive storms come through and usually demolish a chunk of Taiwan, but rarely do much damage on Guam. But it's always close. Windy gives a sense of how much wind we'll get with a very fine grain that's quite intuitive.

Their stand-alone map application Windy Maps is pretty darn nice too. It's a really nice compliment to OsmAnd and GaiaGPS for viewing OSM data, and they've done a good job showing relations which helps illustrate cycling and hiking routes.

I love their wind direction and speed visualization -- it does such a good job conveying exactly what's happening.

The AQI overlay is really interesting to combine with it, since it can give you an idea why certain pockets of air are lower/higher quality.

This is very cool, I’m guessing that Bismarck, North Dakota is the place to be if you are wind farming, looks like a lot of air is being funneled past it. Things get interesting around the Rocky Mountains in general.

Looking at the city Sydney close to the Hurricane, I am really confused... LoL.

If you're confusing it with the Australian city, you should know they're both named after the same person :-)

It’s a cool app but I wonder why there’s no way to change font size, even on iPad when my eyes are waking up or other low light situation it can be hard to read the forecast panel in landscape mode etc..

This page needs some non-scrollable borders for mobile. Once you scroll down a bit into the map, it’s nearly impossible to get back to the browser ui controls

It's like what Weather Underground used to be like.

This looks like the wind hits the West Coast of the United States and "turns" southwards. Is that accurate? If so, what causes it to do that?

High pressure over the north east pacific combined with the Coriolis effect. Also the land sea border has a big influence here in this case in particular.

I wonder how it would look if the speed of the arrows matched the speed of the wind. Perhaps they'd be too slow to be useful when zoomed out.

Been using it for over a year. It's becoming a favorite for Gulf of Mexico fisherman. More accurate than Windfinder most of the time.

I've been using this for a few years to plan out sailing trips. It has been very helpful and accurate to predict wind conditions.

Love this site! Saved me a lot of trouble ahead with preparation of the last few hurricanes and tropical storms in the NY area!

There is also http://hint.fm/wind/

USA only?

My go-to page for checking weather. On windy days I love to open it just to see how things look in a broader perspective:D

Love windy.com, it is great for big weather events, but I have found it going a bit off for day-to-day weather...

I love Windy. It's great for anyone who goes surf fishing. Helps avoid the frustrating days.

I really like Windy's base maps. How did they generate them and what's the style?

They're using Mapy.cz. Same location in Mapy.cz and Google Maps:

https://mapy.cz/turisticka?x=14.1857611&y=49.9310438&z=14

https://www.google.com/maps/@49.931472,14.185431,14z

So pardon my ignorance in all things GIS, but it looks like Mapy.cz serves the tiles which are based on OpenStreetMap. On that Mapy.cz site, there is no style that is similar to Windy. The maps I see are "Basic", "Traffic", "Outdoor", etc.

I'm interested in the grey/outlines basemap like this: https://www.windy.com/-Weather-radar-radar?radar,50.310,1.15... . The shading around the coastlines in particular is exquisite.

How did they generate this grey basemap? Does Mapy.cz offer the tools to generate such a map or do they just host the tiles?

Oh, I thought you meant the map which is visible if you zoom closer on Windy.

The gray map is probably custom made by Windy.

Actually that is an excellent map, thanks!

Check out the stand-alone Windy Maps app. It's basically their OSM-based map layer, all by itself. It's a decently handy lightweight compliment to other heavier OSM tools like OsmAnd and GaiaGPS.

This is also a PWA that you can add to your home screen in iOS for a nice full screen view.

On an ipad the app is a usability disaster. On android the app is ok but the web version has the new features first anyway

Oh, thanks I only tried it on iPhone.

What is the problem with PWA mode on the iPad?

Really helpful in Kolkata , India during Cyclone warnings. I monitor it all the time.

Good site and app. Been using this for years now and is my goto for extreme weather.

Where can I learn about the most effective algorithms for forecasting weather?

Does anyone know what Windy’s business model is?

I’m just curious because it’s not clear to me.

They have a premium subscription with higher-granularity forecasts. [0]

[0] https://community.windy.com/topic/11552/we-are-launching-win...

The business model is that the founder is co-owner of seznam.cz ("czech google/yandex")

Is there an API to get high resolution 3D volumetric data of storm systems?

What stack is this built on? Love Windy and have used it for several years.

PHP, Nginx, particles.js

Incredibly petty: after a mobile pan, keep the lengths on the arrows pls

This one's new to me. Never heard of it before. Thanks!

my fav weather website is https://www.yr.no/ the name means very light rain.

windy is absolutely brilliant and has become the first app I opened whenever I go sailing (aka almost every week)

Where does Windy's data come from?

It'd be cool if you rendered winds aloft, allowing you to change altitude to see the wind at that height.

There appears to be a slider on the right-hand side for this.

Wow!

Damn, that's a fast site!

It's a amazing!

So Simple. Brilliant

Just reading the name of this site makes me want to fart.

Very cool

wow Larry looks scary. I would not feel ok if I lived in Newfoundland or those French islands.

Good site.

I like to watch the current wind reports.

Add that together with twitter reports and flightradar24 and you can actually get some idea what a wildfire is doing. It's an area where government and the local news are essentially useless.

Local emergency dispatch can be another great source.

This is a great site for dispatch streams.

They often have ftac channels too where the firefighters will be communicating.

https://www.broadcastify.com/

There's also MyRadar, but this looks more accurate?

Now if only they can resist the temptation to not fuck up their site with an obligatory unnecessary redesign

Windy’s whole value add can be “not WeatherUnderground or Darksky”

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