Finding the Data

Before we dive in here, please note that the end result of this process is in this repository and this information is presented for posterity's sake.

NOAA is generally a fantastic go-to option for all things weather and oceanic. As such, we'll hunt their archives to see if we can't find something interesting.

After a fairly quick Google search you may find this page: https://www.nhc.noaa.gov/data/tcr/ which lists summary track information for major hurricanes each year. After some more investigation, you'll then find: http://www.nhc.noaa.gov/gis/best_track/al152017_best_track.kmz which is the best track summary of Hurricane Maria.

Once we have our KMZ, we must convert it to KML either using a desktop version of Google Earth or by changing the extension to .zip and unzipping the archive to find the KML hidden within.

Finally, we must hand-edit this particular KML as it is not formatted in such a way as to have all the great additional data read by Openlayers or Cesium. For reference, these changes are made following the KML spec for custom data.

For each <Placemark> there is a set of custom nodes: <lat>, <lon>, <stormName>, <stormNum>, <basin>, <stormType>, <intensity>, <intensityMPH>, <intensityKPH>, <minSeaLevelPres>, <atcfdtg>, and <dtg>. All of those must be wrapped in a parent node, <ExtendedData>, and then transformed into a <Data> node, like so:

...
<Placemark>
    <name>0600 UTC SEP 20</name>
    ...
    <ExtendedData>
        <Data name="lat">
            <displayName>lat</displayName>
            <value>17.6</value>
        </Data>
        <Data name="lon">
            <displayName>lon</displayName>
            <value>-65.1</value>
        </Data>
        <Data name="stormName">
            <displayName>stormName</displayName>
            <value>MARIA</value>
        </Data>
        ...
    </ExtendedData>
</Placemark>
...

Once that's done, save it to src/default-data/demo-default-data/al152017_best_track_Maria.kml