The photographic observation by aircraft was performed on 20 January 1963 as a part of research project of heavy snowfall in Hokuriku District where is located in the central part of the Japan Sea coastal region of the Japan Islands. The horizontal distribution and the topography of clouds over the Japan Sea near Hokuriku District were obtained bymaking use of the aerial photographs taken from the aircraft at about 8 kilometers level in the way based on the usual aerial photogrammetry.
The cloud photographs show a characterisitic pattern changing from scattered cumulus clouds smaller than 1 kilometer in both horizontal and vertical dimensions in the west of the observation area to larger cumulus and cumulonimbus clouds reaching 3 kilometers level in the east where is covered with upper stratiform clouds. It is suggested that cumulus clouds seem to originate over the Japan Sea at least 200 to 300km off the coast of Hokuriku District and a fairly amount of snowmay be released efficiently just in Hokuriku District from the clouds containing sufficient water substance.