Characteristic Analysis of Continuous Rainy Weather in September 2011 in Henan

doi:10.3969/j.issn.1673-7148.2012.04.004

Abstract：Base on the conventional observation data and OLR data and SSI data from FY satellite, the continuous rainy weather in September 2011 in Henan is comprehensively analyzed by objective analy-sis. The results show that Ural blocking high at 500 hPa was maintain stable, the west pacific subtropical high-pressure belt stretched westward under the stable circulation background, the low shear line at 700 hPa developed strongly with the low southwester air torrent, which resulted in continuous rainy weather. The two water vapor conveyor belt from the South China Sea and the Indian Ocean provided plentiful wa-ter vapor and thermal energy. The polar vortex inclined to the western hemisphere, which was conducive to development of Siberian high-pressure ridge. The pressure trough in the northeast of Asia was stable and maintained, which favored warm air to collect in the north of Yellow River. The OLR negative anom-aly showed precipitation intensity was stronger and duration was longer than calendar year' s. The lower SSI accumulated value daily showed precipitation intensity was stronger and SSI was less in surface. The moving path of SSI low value center accumulated value daily was consistent with the moving path of pre-cipitation high value center.