I would be interested in alerts when a particular value combination arises in the forecast.

The overall alert condition is a combination of several subexpressions.

let me lay out the idea by example:

given:
location1, location2, location3, time-of-day1, time-of-day2
maxtemp

if  (temperature(location1, time-of-day1, surface) < maxtemp) AND
    (wind(location1, time-of-day1, surface, IconEU) < 10km/h) AND
    (wind(location2, time-of-day2, FL180, ECMWF) > 80 km/h) AND
    (wind_direction(location2, time-of-day2,FL180, ECMWF) between 290 and 20 degrees)) AND
    (wind(location3, time-of-day3, surface, IconEU) < 10km/h) AND
    (temperature(location2, time-of-day1, surface) < maxtemp)

then
   create alert("Alps crossing possible")

having this done once nightly looking into the future as far as models provide that would be super useful.

I admit the parameterization is complex and probably pushing the envelope for a mobile gui - it might be more productive to address the issue algorithmically (plugin idea!)

thanks for this great tool!

Assuming the average alert user is as clueless about Javascript as I am:

a framework feature for generating alarms, and a set of predefined, selectable (possibly user-contributed) JS fragments (really condition expressions) which can be parameterized:

that would go a long way without the complexity of a full-blown programming language based solution

I thought you might like this:

a local flight in Styria last month:
https://cesium.com/cesiumjs/cesium-viewer/?source=https://static.mah.priv.at/cors/stiwoll-muggauberg.czml

two balloons crossing the Alps late last year:
https://cesium.com/cesiumjs/cesium-viewer/?source=https://static.mah.priv.at/cors/filzmoos-treviso-oesoe-oesfy.czml

the trajectory lines are generated from the GPX files the windy-traj plugin offers as download, the flight tracks are actual GPS data

motivational screenshot of the latter flight:

and here is a 360° video of that flight:

note the whole animation is encapsulated in a single CZML file and just uses the public CesiumViewer service from the Cesium project

• Michael

ps: for the curious: this documents arguments to the CesiumViewer

Re: anybody working on a trajectory plugin?

is that planned to work eventually?
will it never work for some reason?

thanks! pawed through the FAQ and articles - couldnt find an answer

The most prestigious gas balloon race in the world is the annual Gordon Bennet Cup

Pilots stay aloft for several days and might cross the continent

To get an idea, here's a video of the tracks flown this year:

The teams have (and need!) a ground crew which advises pilots on weather and tactics

This year, windy and traj were part of the games - in the ground support for the Belgian, Spanish and US teams - Kolja Packard wrote up a field report (he was part of the support team and worked the weather forecasts):

(this is still german-only, I will post an english translation shortly and notify here):

https://blog.mah.priv.at/index.php/2019/10/01/erfahrungsbericht-einsatz-von-windy-beim-gordon-bennet-cup/

In particular, have a look at the very first image in the blog post - this was the track forecast 20 hours (!) before takeoff

compare that to the youtube video above - the match is amazing!

Many thanks to Kolja in writing this up!

have you considered turning off notifications for a start?

@rittels Thanks for this phenomenal job!

this is already very useful - will do a balloon ride tomorrow early morning and see how that fares relative to the plot!

If I may add a suggestion:

if you select several altitudes on the plot it is hard to discern which track belongs to which altitude

why not choose different colors for each track in the plot and color the altitudes in 'Select levels' accordingly?

• Michael

semi-related: I wrote up a tutorial on Alps crossings with a hot air balloon as there is next to zero material available on the issue

it gives an idea of the meteorological prerequisites: http://static.mah.priv.at/public/alpcrossing/assets/player/KeynoteDHTMLPlayer.html#0

(suggestions for improvement and bug reports welcome)

Here's something neat: visualize an expected balloon flight in 3D based on a windy trajectory:

https://ayvri.com/scene/49j7m8dzje/cjzp38qi200013d5vtyo4jj3j

The GPX file was created with windy.com and the traj plugin. It includes an ascent and descent phase of 2m/s and level flight at 1500m. The GPX file was then uploaded to ayvri.com (free account required).

The ayvri visualization is based on cesium.js - for the curious, play here: https://cesiumjs.org/Cesium/Apps/Sandcastle/index.html?src=CZML Path.html

Here's another long jump - from today

435km in under 4hrs, peak 80kts - and phenomenal forecast accuracy!

https://blog.mah.priv.at/gpsvisualizer/20200105044229-47167-map.html

to explain the little hiccup yesterday:

the radiosonde backend is essentially a database which maps a station ID to a series of radiosonde ascents tagged by time
the station ID is assumed to be globally unique, assigned be the WMO, and hence can be used as primary key.

Or so goes the theory.
In practice, all sorts of junk data comes in, like this beauty

search for 'station_id' and well... its just blanks. And there went the primary key.

The code has been fixed to skip such stations, so we have to live without Tunis/Carthage for now until they fix things there.

Another problem creeping up from time to time is: there is no single, well curated source of WMO station information; there are station lists kept by different organisations in varying degree of accuracy and state of rotting. And sometimes those entries are plain wrong - for instance, wrong coordinates.

this manifests itself by a circle on the map at location X, and when you click it, the trajectory shows up elsewhere on the map.

If you find such a station, please file an issue or pull request against this file.

thanks

• MIchael

Service is back to normal

several station locations have been fixed

service is currently degraded, investigating

Hi @stitch , I'm just the fellow doing the data collection backend

all the frontend polishing is done by the formidable Mister @rittels !

and no, there arent any known existing bugs since @rittels fixes them so quickly, so it's all Heisenbugs ;)

@ivo delighted!

I already primed all my ballooning fellows on this - ICON-D2 is the best model for us in central Europe for flight forecasts

and my farmer neighbours.. I taught some of them to use windy and they are getting pretty good at bringing home the hey before the rain sets in;)

• Michael

@stitch Michael here, author of the radiosonde backend

re sondehub realtime data integration: that was always planned and I'm in contact with the sondehub team since over a year towards that end.

From an integration perspective it looks reasonably straightforward. However, server side things would not be as easy as the current radiosonde backend which is basically serving static files. Also, data quality is an issue - data from sondehub might not be validity checked as the data from meteo aggregators is.

Currently this backend service is running on my hosted server, and its future is undecided as of now.

• Michael

• assume you have an Internet-connected gadget for gliding/parachuting/ballooning (it might be just a Vario using your phone as a hotspot)
• turn gadget on - gadget eventually gets a GPS fix and has location
• the gadget would call an HTTP-based API with location and retrieve a vertical wind profile nowcast (from some model X where X != ECMWF) in return, say as a JSON object, for further use on the device

would you in theory be willing to entertain such a service directly, or suggest using the Windy API and some intermediate server?

IOW: how do you see a non-phone/tablet/desktop usage scenario for Windy services? @ivo @marekd

• Michael

https://news.ycombinator.com/item?id=28486389

coverage compared:

Deutscher Wetterdienst pc_met, €79,50.-/yr, no history/download

Windy Radiosonde, free, with history+download:

Germany: 14 vs 10 stations
British Isles: 8 vs 2
Austria: 3 of 4 not present
Spain: 6 versus 3
Slovakia: 1 vs 0
Hungary: 2 vs 1
Croatia: 2 vs 1
Italy: DWD - 2 out of 4 have "technical issues"

interesting method:

https://nagix.github.io/mapbox-gl-rain-layer/#6.45/62.074/20.167/28/72