Splitting Ageostrophic Diagnostic Method Part Ⅱ : Its application to the sudden heavy rainfall intensification caused by tropical storm Bilis (2006) after its landing

摘要

After the second landfall of tropical storm Bilis (2006),its inner core was dissipated and strength had greatly reduced.However,the remnant of Bilis caused sudden torrential rain at the southwestern quadrant.Before 06UTC 14 July,there is almost no rainfall over inland of China,6h latter,an averaged 30mm/6h rainfall with very few stations of 37mm/6h can be observed at border of Hunan and Jiangxi Provinces at 12UTC 14 July (Fig.1 a).After that,the localized rainfall there increased abruptly from 50mm/6h at 18UTC 14 (Fig.1b) to up to 90mm/6h at 00 UTC 15 (Fig.1c) and 06 UTC 15 (Fig.ld) with a center at (114°E,25°N),especially from 00 UTC 15 to 06 UTC 15 July,the maximum of the precipitation was 96mm/6h.This event was so far under predicted by CMA,which caused a widespread catastrophic flooding and subsequent large loss of life property.