Visibility (a), mean sea-level pressure (b), cloud base height (c), wind direction (d), 2 m temperature and dewpoint (e) and wind speed (f) at Zagreb Airport, Dec 27 2015 00:00 UTC- Dec 30 2015 00:00 UTC. Shaded gray areas indicate periods of fog, while triangles indicate observed precipitation (magenta – drizzle). In (c), green indicates periods when vertical visibility was reported instead of cloud base height. In d), missing observations indicate variable wind direction (180° or more in a 2-min interval) according to definition by ICAO (International Civil Aviation Organization)