Synoptic Classification and Physical Characteristics of Extreme Short-time Heavy Precipitation in Zhumadian During the Warm Season of 2016-2020
Jia Haosong
Wang Lulu
Abstract：According to the upper-air and surface observation data and the ERA5 reanalysis data,the spatial and temporal variation characteristics of extreme short-time heavy precipitation in Zhumadian in the warm season(April-September)of 2016-2020 are analyzed,and the weather background classifi-cation and physical quanitity characteristics are diagnozed.The results show that the extreme short-time heavy precipitation occurs mostly in July and August,and its daily variation is in a three-peak pattern.It occurs more frequently from 16:00 to 18:00,at 00:00,and from 05:00 to 07:00 every day.The ex-tremely short-time severe precipitation with an hourly rainfall intensity exceeding 80 mm/h appears more at 00:00,mostly in the plain in central and eastern Zhumadian.According to the combination of subjec-tive classification and K-means clustering objective classification,extreme short-time heavy precipitation in Zhumadian is divided into five synoptic types,i.e.,the low trough,low eddy and shear combined effect type,the subtropical high influence type,the surface cold front type,the northwesterly flow type and the typhoon inverted trough type.The extreme short-time heavy precipitation exceeding 80 mm/h tends to occur under the condition of first three synoptic types.According to the physical quantity diagno-sis of the synoptic types,the low trough,low eddy and shear combined effect type has the largest water vapor flux in the lower tropasphere,the surface cold front type has high humidity in the ambient field,and the northwesterly flow type has drier stratification with relatively larger dew point on the surface.Each weather type has a certain degree of unstable energy.The dynamic conditions of the low trough,low eddy and shear combined effect type is the strongest in the whole layer,the low-level dynamic conditions of the surface cold front type are stronger,while the dynamic conditions of the other three types are rela-tively weaker.The 0 ℃ layer height of each type,except for the low trough,low eddy and shear com-bined effect type,is higher than 5.4 km.Finally,the average physical quantities of extreme short-time heavy precipitation in this study are compared to the average physical quantities of short-time heavy pre-cipitation in the upper reaches of the Huai River(Zhang Yiping et al.,2014)and the result suggests that the difference in physical quantity is not distinct except that the CAPE is twice as high.
Keywords：extreme short-time heavy precipitationspatio-temporal distributionsynoptic classifi-cationphysical quantity characteristics
Publication Date：2024-12-28
Online Publishing Date：2026-09-12(First online date of this platform, not the publication date of the document)
Pages：9( 37-45 )