Use the weather picker

The weather picker works only on desktop and is not intended for mobile use. It resides at windyApi.picker. It can be opened programmatically by calling .open({ lat, lon }) or closed by .close() methods.

If the picker is opened outside of the visible map, it can lead to an exception or it is closed afterwards. Also panning the map, so the picker gets outside the map, leads to auto closing of the picker. The picker emits messages about its own state, so use methods .on(), .off() or .once() to observe pickerOpened, pickerClosed and pickerMoved broadcasts.

While the picker is opened, use its method .getParams() to get picker coordinates and raw meteorological values in the location of the picker.

Converting raw meteorological values to readable numbers

Raw meteorological units returned from the weather picker are usually described in respective documentation for ECMWF, GFS or other used forecast models. Use windApi.utils to convert these values to something more useful.

Most popular overlays have these values:

wind

Array [ U, V ], where U and V are wind vectors in m/s. To compute wind magnitude and direction use utils.wind2obj( values ), which returns { dir: 210.4334, wind: 10.2 }

temperature, dewPoint

Temperature in K

rain, rainAccumulation

Rain for a duration of 3 or the selected accumulation period in mm

waves, swell

Array [ U, V, size] where U and V are direction vectors and wave size is in m. Period in seconds is computed as Math.sqrt( U * U + V * V ). Use utils.wave2obj( values ), which returns { dir: 325.9878, size: 2.4, period: 8 }

To convert values to user's selected metrics use .convertNumber(num) or .convertValue(num) methods of respective overlays instance. While converNumber just recalculates value and return a number, convertValue adds name of a metric and returns a string. For example overlays.wind.convertNumber(10) returns 19, while overlays.wind.convertValue(10) return "19kt".

Source code

HTML


<html>
    <head>
        <meta
            name="viewport"
            content="width=device-width, initial-scale=1.0, shrink-to-fit=no"
        />
        <script src="https://unpkg.com/leaflet@1.4.0/dist/leaflet.js"></script>
        <script src="https://api4.windy.com/assets/libBoot.js"></script>
        <style>
            #windy {
                width: 100%;
                height: 300px;
            }
        </style>
    </head>
    <body>
        <div id="windy"></div>
        <script src="script.js"></script>
    </body>
</html>

JavaScript


const options = {
    key: 'PsLAtXpsPTZexBwUkO7Mx5I', // REPLACE WITH YOUR KEY !!!
    lat: 50.4,
    lon: 14.3,
    zoom: 5,
};

windyInit(options, windyAPI => {
    const { picker, utils, broadcast } = windyAPI;

    picker.on('pickerOpened', latLon => {
        // picker has been opened at latLon coords
        console.log(latLon);

        const { lat, lon, values, overlay } = picker.getParams();
        // -> 50.4, 14.3, 'wind', [ U,V, ]
        console.log(lat, lon, values, overlay);

        const windObject = utils.wind2obj(values);
        console.log(windObject);
    });

    picker.on('pickerMoved', latLon => {
        // picker was dragged by user to latLon coords
        console.log(latLon);
    });

    picker.on('pickerClosed', () => {
        // picker was closed
    });

    // Wait since wather is rendered
    broadcast.once('redrawFinished', () => {
        picker.open({ lat: 48.4, lon: 14.3 });
        // Opening of a picker (async)
    });
});