強雨をともなうサブシノプテックスケールの寒冷渦

Abstract

Detailed analyses are made on a subsynoptic-scale cold vortex which caused the intense convective precipitation while it passed over Japan on 9-10 May 1980. This cold vortex was embedded in a large-scale trough and associated with a dome shaped cold air. The stable layer which bounded the cold dome was not distinct over the eastern part of the dome. The cold dome boundary was well defined, rather, by the horizontal temperature gradient. It is found from GMS imageries that the subsynoptic-scale cloud system relevant to the cold dome was located 1000km behind the cloud system associated with a synoptic cyclone and frontal system. This subsynoptic-scale cloud system was formed in the eastern quadrant of the dome-shaped cold air, while the precipitation was concentrated in the southern quadrant. The maximum precipitation intensity took place in coincidence with a rapid increase of aerial coverage of lower TBB values. Cumulus convections penetrated through the cold dome boundary and reached to the level of tropopause funnel.A forecast experiment is performed by using a fine-mesh primitive equation model, and some of characteristic features of the subsynoptic-scale cold vortex are well simulatedd if the reanalyzed fine structure is incorporated in the initial field.