中国季风区的区域性暴雨过程大多与低空急流有关， 然而在干旱、 半干旱地区， 每一次暴雨过程却不一定都有低空急流配合。根据南疆44个国家气象站1971 -2020年5 -9月逐日降水资料和2011 - 2020年逐小时降水资料， 以及若羌站每日2 次的探空资料， 利用统计方法， 分析了近50 a南疆东风急流暴雨与非东风急流暴雨的观测特征差异， 以及造成二者的天气系统差异。结果表明： 近50 a南疆东风急流暴雨日数略少于非东风急流暴雨日数， 二者均呈增加趋势， 但东风急流暴雨日数的增加趋势更显著； 东风急流暴雨日数占南疆总暴雨日数的比例呈增加趋势， 非东风急流暴雨日数占比呈下降趋势。南疆暖季东风急流暴雨日数在5月最多， 非东风急流暴雨日数在7月最多， 二者均在9月最少。20世纪70~90年代， 南疆暖季以非东风急流暴雨为主， 自21世纪起， 以东风急流暴雨为主。南疆西（东）部地区的暴雨日数相对较多（少）， 且以东风（非东风）急流暴雨为主。短时强降水事件在南疆暖季非东风急流暴雨中出现的比例明显高于东风急流暴雨； 约80%（60%）的东风（非东风）急流暴雨日的平均降水时数大于（小于）6 h， 东风（非东风）急流暴雨以夜（日）雨为主。南疆暖季东风急流暴雨的最大降水时段和最多发生时段都主要在午夜前后； 而非低空急流暴雨的最大降水时段则多发生在午后至傍晚， 其最大累积频次与急流暴雨类似也出现在午夜前后； 两类暴雨的最大雨强都发生在午后至傍晚。南疆暖季东风急流暴雨降水量在前半夜的峰值主要由降水频次多所导致， 而其在傍晚前后降水量的次峰值则主要由降水强度大造成。南疆暖季非东风急流暴雨降水量的日变化特征与其降水强度类似， 与其降水频次的差异较大， 其降水量与降水强度的关系更密切。100 hPa南亚高压在南疆暖季东风急流暴雨和非东风急流暴雨中的差异较大， 500 hPa上中亚低槽（涡）在二者中均占主要地位。目前， 针对有塔里木东风低空急流配合的南疆暴雨的形成机制研究相对成熟， 而对无塔里木东风低空急流配合的暴雨过程的形成机制还不清晰。

Most of the regional heavy rain processes in the monsoon region of China are related to the low-level jet.However， in arid and semi-arid regions， the low-level jet stream is not necessarily associated with every rainstorm process.Based on the daily precipitation data from May to September from 1971 to 2020， hourly precipitation data from 2011 to 2020， and the radiosonde data from Ruoqiang Station twice a day， the observational characteristics of heavy rain with and without easterly low-level jet in southern Xinjiang in recent 40 years were analyzed by statistical methods.The results show that the number of rainstorm days accompanied by easterly low-level jet is slightly less than that without easterly low-level jet in southern Xinjiang in recent 40 years.Both of them showed an increasing trend in the past 40 years， but the increasing trend of the number of rainstorm days accompanied by the easterly low-level jet was more significant.In the past 40 years， the proportion of rainstorm days accompanied by easterly low-level jet to the total rainstorm days in southern Xinjiang showed an increasing trend， while the proportion of rainstorm days without easterly low-level jet showed a decreasing trend.In the warm season of southern Xinjiang， the number of rainstorm days accompanied by easterly low-level jet was the highest in May， while the number of rainstorm days without easterly low-level jet was the highest in July， and both of them were the least in September.From the 1970s to the 1990s， the heavy rain in the warm season in southern Xinjiang was mainly accompanied by the easterly low-level jet， and from the 2000s to the present， the heavy rain was mainly accompanied by the easterly low-level jet.The number of rainstorm days is relatively higher in the western part of southern Xinjiang， and the rainstorm is mainly accompanied by easterly low level jet stream.The proportion of short-time heavy precipitation events in the rainstorm without the easterly low-level jet in the warm season in southern Xinjiang is significantly higher than that in the rainstorm with the easterly low-level jet.The rainstorm accompanied by the easterly low-level jet is dominated by night rain， while the rainstorm without the easterly low-level jet is dominated by day rain.In the warm season of southern Xinjiang， the periods of maximum precipitation and maximum occurrence of the rainstorm with the easterly low-level jet mainly occurred around midnight， while the periods of maximum precipitation of the rainstorm without the easterly low-level jet mainly occurred from late afternoon to late afternoon.The maximum cumulative frequency of the rainstorm without the easterly low-level jet is similar to that of the rainstorm with the easterly low-level jet occurred around midnight.The maximum intensity of both types of torrential rain occurs from mid-afternoon to late afternoon.The peak value of rainstorm precipitation with easterly low-level jet in the warm season in southern Xinjiang was mainly caused by the frequency of precipitation in the early night， while the sub-peak value of rainstorm precipitation around evening was mainly caused by the intensity of precipitation.The diurnal variation characteristics of rainstorm precipitation without easterly low-level jet in the warm season in southern Xinjiang are similar to its precipitation intensity， and the difference between it and its precipitation frequency is great.There is a great difference between the rainstorm with easterly low level jet and the rainstorm without easterly low level jet in the warm season of southern Xinjiang.At present， the research on the formation mechanism of rainstorm in southern Xinjiang with the coordination of easterly low level jet from Tarim is relatively mature， while the formation mechanism of rainstorm without the coordination of easterly low level jet from Tarim is still unclear.