冷涡背景下鲁中地区短时强降水特征分析

Characteristic Analysis of Severe Short-time Precipitation in Central Shandong under Cold Vortex Background

该文利用鲁中地区25个国家级气象观测站2002—2019年5~8月逐小时降水量资料,统计分析了冷涡背景下短时强降水的时空分布特征及其与冷涡的关系。结果表明:(1)鲁中地区短时强降水日数和站次的大值区主要分布在海拔较高的中西部山区,低值区分布在海拔较低且为平地的鲁中东部。(2)34.6%的短时强降水日发生在冷涡背景下,鲁中地区短时强降水日数和站次在7月份最多,5月份最少;6月份冷涡作用最为显著;短时强降水多发时次集中在16时~次日02时。(3)鲁中地区以出现1~2个站的局地短时强降水为主;短时强降水以20~30 mm雨强为最多,7月份雨强超过50 mm的站次最多。(4)局地短时强降水发生时,冷涡中心多分布在115°E~137.5°E、47.5°N~55°N的矩形范围内,大范围短时强降水对应的冷涡中心分布范围最小;冷涡越强,短时强降水范围越大。

Using the hourly precipitation data of 25 national meteorological stations in central Shandong Province from May to August of 2002~2019,the characteristics of spatio-temporal of severe short-time precipitation under cold vortex background and its relationship with cold vortex is analyzed.The results are as follows:(1)Severe short time precipitation in central Shandong mainly occurs in the central and western mountainous areas with high altitude,and less occurs in the lower and flat areas in east of central Shandong.(2)34.6%of severe short-time precipitation occurs under cold vortex background.The number of severe short-time precipitation days and stations in central Shandong mainly occur in July and less in May;cold vortex plays the most important role in June;severe short-time precipitation mainly occurs from 16:00 to 02:00 next day.(3)Local severe short-time precipitation with 1~2 stations is the main situation in central Shandong;the rainfall of severe short-time is concentrated between 20 to 30 mm per hour,and the rainfall more than 50 mm per hour mainly occurs in July.(4)Cold vortex centers are mostly distributed in the rectangular range of 115°E to 137.5°E and 47.5°N to 55°N when local severe short-time precipitation occurs.And the distribution of cold vortex centers is more concentrated when large-scale severe short-time precipitation occurs;the stronger the cold vortex,the larger scale of short-term heavy precipitation occurs.