Abstract
The cold fronts that passed Nagano and its neighbourhood in January, February, March and December 1946, are investigated.
It is shown that when the air on the lee side of the mountain ranges is colder than the air in the rear of the cold front, it sometimes happens that this front does not overrun, but near the surface temperatures rise and frontal activities are weak, on account of the dynamical causes of foehn phenomena. Masked phenomena are treated from the standpoint of foehn phenomena. An example of masked phenomena of the second kind and snowfall in the monsoon at Nagano are investigated.
