The non-null, non-empty ID of the weather station that
the StationIdLocation should represent (i.e. the
station you want data for). Cannot contain contain any characters
other than [-_0-9a-zA-Z], and cannot contain more
than 60 characters (a limit that is significantly larger than the
length of any station ID that we are currently aware of, but that
is set high to allow for "virtual station IDs" to be introduced in
the future, combining data from multiple stations).