近10年保定夏季暴雨过程中地面水汽压的分布特征

Distribution Characteristics of Surface Vapor Pressure during Summer Rainstorm of Baoding in Recent 10 Years

文章选取了2010—2019年保定19个国家站的238站/次暴雨过程,对降水发生前地面最大水汽压的分布状态进行了分析,并以1981—2010年的区域平均作为气候值,结果发现:3个以上台站的地面最大水汽压在7月中旬—8月中旬超过气候值4 hPa、其余时段超过5 hPa可作为暴雨预报的指标;配合不稳定形势,1—2个台站在7月中、下旬达到气候值,或其余时段超过气候值2 hPa可作为单站暴雨的参考依据;7月中、下旬,暖区降水和高空槽降水叠加时,地面最大水汽压达到25 hPa和29 hPa分别为50 mm和150 mm降水的预报指标;8月下旬,山区地面最大水汽压达到气候值时台站可能出现可暴雨。

This study analyzes the distribution of maximum surface vapor pressure before precipitationbased on 238 timesrainstormevents of 19 national stations in Baoding city from 2010 to 2019.It takes the regional average value of maximum surface water vapor pressure from 1981 to 2010 as climatic value.The results show that the maximum surface water vapor pressure of more than 3 stations exceeded 4 hPa from mid-July to mid-August,and exceeded 5 hPa in other time periods,which could be used as the index of rainstorm forecast.In accordance with the unstable situation,1-2 stations reach the climatic value in mid-july and late July,or exceed the climatic value of 2 hPa in other time periods,which can be used as the reference basis for the rainstorm of a single station.In mid-july and late July,when the precipitation in the warm sector and the precipitation caused by high trough were superposed,the forecast index of50 mm precipitation requires a surface water pressure of 25 hPa,meanwhile,the forecast index of 150 mm precipitation requires a surface water pressure of 29 hPa,Heavy rain may occur at the station when the maximum water vapor pressure on the ground reaches the climatic value In late August.