Journal of Natural Disaster Science

FORMATION MECHANISM OF A NOTABLE CLOUD SYSTEM THAT CAUSES HEAVY SNOWFALL AND A TENTATIVE PREDICTION OF ITS BEHAVIOR

Tatsuo ENDOH
Associate Professor, Institute of Low Temperature Science, Hokkaido University
Kunihiko HOZUMI
Shari High School
and
Choji MAGONO
Professor emeritus, Hokkaido University

(Received 4 Jun., 1984 and in revised form 27 Sept., 1984)

Abstract

Most severe snowfall in Japan are associated with pressure distribution of the monsoon type. When cold monsoon bursts spread aloft over the Sea of Japan, numerous cloud streak that are aligned in parallel from the Coast of the Asian continent to the Japanese archipelago. These bursts are accompanied by a constant snowfall and local traffic problems are produced because of this concentrated snowfall. Therefore, forecasts of cloud behavior are needed. At present, such predictions have been successful to some extent.

In all the especially heavy snowfall studied, a notable cloud system grew and aligned itself on an intermediate scale from the east coast of the Korean Peninsula to the west coast of the Japanese islands. This type of system produces the highest peak values for snowfalls as in the severe winter snowfalls of 1968 and 1981. To investigate the generation mechanism of this type of cloud system, observations were made with balloons and from an aircraft. Tentative predictions of the behavior of this monsoon type system were made.

Key words

heavy snowfall, convergence cloud system, prediction