This paper describes the regional characteristics of snow disaster in Akita Prefecture and the maximum depth of snow cover in Akita City investigated using several kinds of time series data since the beginning of observation.
The problem is considered in four main sections : meteorological conditions of heavy snowfall, aspects of maximum depth of snow cover, historical profile of snow disaster, and estimate of maximum depth of snow cover. The following are revealed by statistical analyses.
(1) The occurrence of heavy snowfall in Akita Prefecture is attributed to the unusual path of a cold vortex differing from the ordinary Hokuriku pattern.
(2) The year of heavy snowfall in Akita City comes in general with a period of about 11 years, and there also exists a periodic time of about 2 weeks of a cold wave in the snowy season.
(3) The present maximum depth of snow cover is influenced by the last summer's meteorological conditions : it is generally in inverse proportion to precipitation, while it is proportion to maximum mean temperature.
(4) There is a close correlation between snow disaster (snowstorm, hailstorm, and frost) and the number of sunspots. Damages by them are likely to occur around the year of minimum number of sunspots.
(5) The majority of avalanches in Akita Prefecture are of creeping type. This may be ascribed to wet snow.
(6) The validity of the multiple regression method using the data mentioned in (3) is demonstrated by the reasonable agreement between the predicted values and the observed values of maximum depth of snow cover.

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