Journal of Natural Disaster Science

ON THE QUASI-STATIONARY RAINBAND OBSERVED IN THE KANTO DISTRICT ON 9 SEPTEMBER 1976

Tomio ASAI
Professor
and
Kimiko TANAHASHI
Ocean Research Institute, University of Tokyo, Tokyo

(Received 4 October, 1982 and in revised form 15 December, 1982)

Abstract

A detailed analysis is made of a remarkable rainband associated with heavy rainfall observed the morning of 9 September 1976 in the Kanto District. The scale of the rainband was about 10 km in width and 100 km in length extending south-southwest to north-northeast. It is shown that the rainband was formed through the alignment of a number of convective clouds successively generated over the mountainous region in the southern part of Izu Peninsula which moved nearly at the same velocity as the wind between a level of 700 and 850 mb. At the lower levels of this rainband warm and moist air flowed in from the east, while colder air flowed out of the rainband to the west. It is suggested that a flow pattern in the vertical cross-section perpendicular to the rainband is favorable for enhancing and maintaining convective clouds and results in the formation of a rainband parallel to the mean wind throughout the troposphere.

Key words

rainband, radar echo, convective cloud, heavy rainfall, precipitation, Kanto district