高级搜索

昆明市雨季短时强降水特征及主要影响系统分析

An Analysis of characteristics and main influential systems of short-duration heavy precipitation during the rainy season in Kunming

  • 摘要: 短时强降水是昆明市雨季主要的灾害性天气,深入研究其时空特征及影响系统,对提升本地强降水预报预警能力具有重要意义。基于2018—2022年昆明市12个国家级气象观测站(以下简称国家站)和406个高密度区域自动气象观测站(以下简称区域站)逐小时降水资料,采用统计学与天气学诊断方法,分析了昆明市雨季(5—10月)短时强降水的时空分布特征,并对区域性过程进行环流分型。结果表明:短时强降水空间分布呈“南多北少”的特征,主城区表现出频次最多、强度最强的“雨岛效应”。主汛期(6—8月)短时强降水出现频次最为集中,其中,短时强降水峰值出现在7月,而极端短时强降水峰值在6月。日变化则呈双峰结构,峰值主要出现在凌晨和傍晚。影响昆明市区域性短时强降水的主要天气系统可分为4类:切变线型(50.7%)、热带低值系统型(20.8%)、两高辐合型(17.4%)和副热带高压外围型(10.1%)。其中,切变线型为主要影响系统,多集中于6月和8月;热带低值系统型多见于7月;两高辐合型则主要出现在8月。

     

    Abstract: Short-duration heavy precipitation is a primary hazardous weather event during the rainy season in Kunming. Conducting an in-depth study of its spatiotemporal characteristics and influencing systems is of great significance for enhancing local forecasting and warning capabilities for heavy precipitation. Based on hourly precipitation data from 12 national meteorological stations (referred to as national stations) and 406 high-density regional automatic meteorological stations (referred to as regional stations) in Kunming from 2018 to 2022, this study employed statistical and synoptic diagnostic methods to analyze the spatiotemporal distribution characteristics of short-duration heavy precipitation during the rainy season (May to October) and performed circulation classification for regional events. The results showed that spatially, short-duration heavy precipitation exhibited a pattern of "more frequent in the south and less in the north," with the main urban area demonstrating a "rain island effect" characterized by the highest frequency and intensity. Temporally, its occurrence was most concentrated during the main flood season (June to August), with the peak of ordinary short-duration heavy precipitation in July, while the peak of extreme short-duration heavy precipitation was in June. The diurnal variation presented a bimodal structure, with primary peaks in the early morning and late afternoon. The main weather systems influencing regional short-duration heavy precipitation events in Kunming were classified into four types: shear line type (50.7%), tropical low-pressure system type (20.8%), two-high convergence type (17.4%), and subtropical high periphery type (10.1%). Among them, the shear line type was the dominant system, occurring predominantly in June and August; the tropical low-pressure system type was most frequent in July, and the two-high convergence type mainly occurred in August.

     

/

返回文章
返回