About Meteo Watchdog
What this app is, where its wind data comes from, and how it works. Written to match what the code actually does.
What Meteo Watchdog is
Meteo Watchdog is a free web app for kitesurfers, windsurfers and wingfoilers. It shows a live wind map built from real weather stations and airports, lists wind-sport spots on lakes, reservoirs and the coast, and sends you a wind alert when the conditions at a station match the wind, gust and direction you set.
Coverage is mainly Slovakia, plus a few stations on the Croatian coast around Pag, Nin and Premantura. Built by wind lovers, for wind lovers.
Where the wind data comes from
Every reading on the map carries a label saying where it came from. These are the sources:
- Weather Underground personal stationsWeather stations run by their owners. The data reaches us through the API of The Weather Company.
- Airport METAR reportsOfficial aviation weather observations from Poprad-Tatry, Bratislava-Ivanka, Košice, Piešťany and Žilina airports, read from the NOAA Aviation Weather Center. Airports report about every 30 minutes, and a gust appears in a report only when it exceeds the average wind by at least 10 knots.
- ALADIN model (ČHMÚ)The forecast model of the Czech Hydrometeorological Institute, served through Open-Meteo. It is used for the Slovak lake and reservoir spots.
- Open-Meteo modelModel points at Šimuni, Premantura and Poprad-Tatry airport.
- MET Norway modelA second, independent model for the Šimuni and Premantura points.
Private stations and credits
Four private stations are read directly from their owners' public data. Each one links back to its owner's page:
- KDLX Gečakdlx.antik.sk
- Meteo Raslavicemeteoraslavice.sk
- Levoča – Západ 1pocasielevoca.sk
- Meteostanica Breznopocasiebrezno.sk
The data from Levoča – Západ 1 comes from pocasielevoca.sk, whose site refers to the Creative Commons CC BY-NC-SA 3.0 CZ licence. We therefore credit that source directly here and link to it from the station's page.
Map imagery and labels are provided by Esri (the labels also by HERE, Garmin and OpenStreetMap contributors).
Sensors and models
A sensor is a measurement: an anemometer at a particular place recorded this wind. A model is a computed value for a coordinate: a weather model's estimate of the wind there, which can differ from what a rider feels on the water.
The map never blurs the two. Models get a dashed marker and a model label, they are hidden by default and have to be switched on in the map filters, and a model value is never merged into a real sensor's reading.
Readings can be delayed, a station can drop out, and a sensor on a roof or next to a building does not necessarily match the wind on the water. Treat the numbers as a guide and use your own judgement before you go out.
How a spot learns when it works
Each spot learns its own good conditions from the people who ride there. After a session, a signed-in rider can rate the spot from 1 to 5, say which sport it was (kite, windsurf or wingfoil) and, optionally, when the session started and ended. SUP is not rated, because it does not depend on wind.
The wind stored with a rating is not typed in by the rider. The server saves its own blended reading of the nearby stations at that moment or, if you gave the session times, averaged over that session (falling back to the current reading when nothing was recorded for those hours). The blend uses stations that have reported recently. By default these are all stations within 15 km: closer stations count far more (the weight falls with the square of the distance), airports count double and models count half. The site's administrator can also mark a station as primary, normal or ignored for a spot, because a station farther away, in the same valley for example, can describe a spot better than the one next to it. A station between 15 and 30 km is used only when it has been marked primary or normal or when riders' ratings have proven it (see below), and an ignored station is never used. If at least one primary station has reported recently, only the primary stations make the estimate (the closer one counting somewhat more, airports double, models half); otherwise the normal ones do.
Riders can also say how strong the wind felt: light (under 12 km/h), moderate (12 to 20), strong (20 to 28) or very strong (over 28). The app stores what every station within 30 km read for that session and compares it with the answer. Once a station has at least 5 such answers at a spot, its track record starts to matter more than its distance: its distance weight becomes a mild one (half at 10 km, instead of falling with the square of the distance) and is multiplied by a factor between 0.25 and 4 that compares its average error with that of the other stations at the spot. A station is never switched off this way, and the manual primary and ignore settings always win. A station between 15 and 30 km that nobody has set joins the estimate by itself once its factor is at least 1, meaning it is at least as accurate as the typical station (at least two stations must have been rated at the spot). Each spot page lists the stations behind its estimate, with each one's share and current reading.
From the ratings of 4 and 5, the spot learns its wind and gust range and the wind directions it works in. Many spots work in several unrelated directions, so these are kept as separate sectors instead of being averaged into one: the middle between two working directions is often exactly where it does not work. This is learned separately for each sport.
Until a spot has at least 3 good ratings (for the sport in question), it does not guess: it says it does not know yet. A reading just outside the learned range is shown as marginal, and if no station nearby has reported recently the spot says there is no data.
This is plain arithmetic, deliberately with no AI involved, so every verdict has an exact reason that can be checked.
Wind alerts
In your account you create a watchdog for a station: a threshold for wind or gusts and, optionally, a range of directions. When the conditions hold for a few minutes, Meteo Watchdog notifies you by e-mail, Telegram or web push, or any combination you choose per watchdog. Web push works in the browser and in the installed web app, separately on each device.
Holiday mode pauses all three channels at once without touching your watchdogs.
Contact
Questions or corrections? Write to [email protected]