Abstract
Photographic observations from aircraft were carried out on the snow clouds in December 1960. The results of observations will be described separately under the following three headings : that is, layer clouds, shower clouds and snow trails. It was concluded from analysis of the photograph of the layer clouds (Photo. 1) that the distance between two precipitating cells was reasonable in comparison with the calculated value of the wave length of the internal waves, as described in section 3 a). The formation of the ragged cloudlets near the shower clouds (Photos. 6 and 7) can be explained as due to lifting of the air by the downdraf t spreading out of the shower clouds. The observed shapes of the snowtrails in Photo. 5 was in agreement with that estimated from the wind profile as seen in Fig. 8.
