Update: the following are relevant lines from /var/log/syslog:
Oct 19 18:10:09 debian mateweather-app[3922]: Failed to get METAR data: 404 Not Found.
Oct 19 18:10:09 debian mateweather-app[3922]: Failed to get IWIN forecast data: 404 Not Found
Oct 19 18:10:09 debian mateweather-app[3922]: Source ID 50501 was not found when attempting to remove it
Oct 19 18:14:54 debian mateweather-app[3922]: Failed to get METAR data: 404 Not Found.
Oct 19 18:14:54 debian mateweather-app[3922]: Source ID 50562 was not found when attempting to remove it
Oct 19 18:23:55 debian clock-applet[3927]: Failed to get METAR data: 404 Not Found.
Note that two different applications are affected by this bug.
Best regards,
Greg Marks