Convergent Cloud Bands over the central Japan Sea were observed by photographing clouds from an airliner in the winter monsoon period. The cloud structure of the band was analyzed by the use of the aerial photographs. Considering the data of radar pictures and daily amount of snowfall, it was shown that the Convergent Cloud Bands have a cloud bank line in its south-west boundary, and that the bank line brought heavy local snowfall in San-In District.
The formation mechanism of the cloud band was discussed, and a structural model of the Convergent Cloud Band was proposed.