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利用常规观测资料和卫星、自动站、加密雨量站、多普勒雷达等资料,对2008年9月24～26日广西崇左市强台风"黑格比"造成强降水过程进行天气动力学和物理量场分析,结果表明:"黑格比"前期造成的强降水比较合理,后期由于高层南亚高压、西太平洋副热带高压和黑海低压及地形作用,导致了台风低压环流后部对流云团发展造成崇左市大暴雨的极端天气灾害事件的发生. 相似文献
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《青海气象》2017,(2)
2016年8月16-18日巴彦淖尔市出现一次致灾大暴雨天气过程,降水强度大,持续时间短,局地性强。本文利用常规资料和自动站、卫星、雷达资料及ECMWF和T639数值预报产品对大暴雨天气过程的成因及漏报原因进行了分析,结果表明:(1)东移的短波槽叠加在暖区上空造成大气层结不稳定是此次暴雨过程的触发机制。副热带高压移动缓慢,西南暖湿水汽输送加强,地面低压稳定少动,是本次暴雨产生和维持的条件;(2)高低空急流、切变线和地面辐合线为此次暴雨过程的发展提供了水汽条件和动力条件;(3)利用卫星云图、雷达资料的演变来确定中小尺度系统的位置、强度和发展趋势,以提前开展强降水等强天气的预报和预警工作;(4)ECMWF预报场未报出短波槽东移,T639预报的短波槽位置偏南,预报员过度依赖数值预报产品是导致本次过程暴雨漏报的主要原因。ECMWF预报场偏弱,T639预报场偏离实况较大,间接导致了暴雨的漏报。 相似文献
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《北方暴雨预报方法》研究课题阶段成果交流会,于5月8—12月在郑州市召开。会议共收到论文80篇,大会交流了36篇。 这次大会交流论文的主要内容是:北方暴雨天气气候特征,短期预报方法;短时预报方法和暴雨系统的诊断分析与数值试验等四个方面。在暴雨的天气气候方面,主要分析了北方暴雨和短时强降水的时空分布、演变过程、环流背景、天气系统和地形的作用,为建立暴雨短期和短时预报思路及方法做了必要的基础分析工作。研究表明,与我国南方强降水相比,北方强降水具有历时短、强度大、时间 相似文献
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黄淮地区一次冷锋暴雨天气过程的预报分析 总被引：1，自引：0，他引：1
利用常规天气图、地面加密资料、数值预报产品、卫星云图和多普勒天气雷达资料等,对2007年7月18-19日出现在黄淮地区的暴雨天气过程进行了综合分析.结果表明:暴雨是高空西风槽、冷锋和副热带高压边缘强盛的西南暖湿急流共同作用产生的;强降水产生在地面中尺度辐合线附近.在高层干冷、低层暖湿的大气不稳定条件下,地面冷空气的侵入触发了不稳定能量的释放,同时低层辐合、高空辐散的高低空配置,引发了强降水的产生.卫星云图和多普勒天气雷达资料在暴雨临近预报中起着重要作用. 相似文献
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暴雨是安康地区重要灾害性天气之一,特别是持续性暴雨,常常引起山洪爆发和河流泛滥,造成严重灾害。因此对持续性暴雨天气的研究和预报特别重要。１９９７—０７—１８日、１９日连续两天,安康地区出现了区域性暴雨天气,下面从能量天气学的角度进行分析。１环流形势演变特点从历史资料看,安康地区出现持续性暴雨天气的环流形势多为：副热带高压增强西进和青藏高压加强东压,且稳定维持,我区处于两高之间切变线前的西南气流中。所以在持续性暴雨的预报过程中,副热带高压和青藏高压的强弱和进退的预报尤为重要。在这次预报过程中,我台… 相似文献
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使用常规气象资料、GMS-5卫星云图以及物理量场分布，分析2000年7月16日辽河流域强降水天气过程的中尺度系统形成发展、云团演变特征和环境场条件。揭示辽河流域强降水天气过程环流背景及暴雨成因，为区域性暴雨预报提供预报依据。 相似文献
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利用常规资料和数值预报资料分析了贵州省一次大暴雨过程,分析表明：此次贵州大暴雨天气过程是在稳定的环流形势下发生的。青藏高压和西太平洋副热带高压的势力强弱是决定此次强降水落区的重要因素。昌都附近出现高压,对于中低层横切变南段的移动起到关键作用。 相似文献
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A. K. Guèye Serge Janicot A. Niang S. Sawadogo Benjamin Sultan A. Diongue-Niang S. Thiria 《Climate Dynamics》2012,39(9-10):2251-2272
The aim of this work is to define over the period 1979–2002 the main synoptic weather regimes relevant for understanding the daily variability of rainfall during the summer monsoon season over Senegal. “Interannual” synoptic weather regimes are defined by removing the influence of the mean 1979–2002 seasonal cycle. This is different from Part I where the seasonal evolution of each year was removed, then removing also the contribution of interannual variability. As in Part I, the self-organizing maps approach, a clustering methodology based on non-linear artificial neural network, is combined with a hierarchical ascendant classification to compute these regimes. Nine weather regimes are identified using the mean sea level pressure and 850?hPa wind field as variables. The composite circulation patterns of all these nine weather regimes are very consistent with the associated anomaly patterns of precipitable water, mid-troposphere vertical velocity and rainfall. They are also consistent with the distribution of rainfall extremes. These regimes have been then gathered into different groups. A first group of four regimes is included in an inner circuit and is characterized by a modulation of the semi-permanent trough located along the western coast of West Africa and an opposite modulation on the east. This circuit is important because it associates the two wettest and highly persistent weather regimes over Senegal with the driest and the most persistent one. One derivation of this circuit is highlighted, including the two driest regimes and the most persistent one, what can provide important dry sequences occurrence. An exit of this circuit is characterised by a filling of the Saharan heat low. An entry into the main circuit includes a southward location of the Saharan heat low followed by its deepening. The last weather regime is isolated from the other ones and it has no significant impact on Senegal. It is present in June and September, and missing in July and August, meaning that this is a weather regime more specific of the intermediate seasons than the summer. It is included in a large-scale pattern covering the northern latitudes of Europe. The correspondence between these “interannual” synoptic weather regimes and the “pure” synoptic regimes defined in Part I has been established. By selecting a high statistical significance level for these correspondences, each of five out of nine “interannual” weather regimes has a close correspondence with one “pure” synoptic weather regime, one out of them have links with two “pure” regimes, and the last three regimes have no significant correspondence in terms of “pure” regimes. However when considering more moderate links, two out of these three regimes show a connection with a “pure” regime, and the last one remains isolated. The ensemble of the weather regimes occurrences can explain a significant part of interannual variability of summer rainfall amount over Senegal, especially linked to the driest and the wettest weather regimes occurrences. It is also shown that Senegal rainfall state is very sensitive to a small displacement or deformation of the weather regime patterns. 相似文献
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This paper reviews the major progress on development of the science and prediction of heavy rainfall over China since the beginning of the reform and opening-up of new China(roughly between 1980 and 2019). The progress of research on the physical mechanisms of heavy rainfall over China is summarized from three perspectives: 1) the relevant synoptic weather systems, 2) heavy rainfall in major sub-regions of China, and 3) heavy rainfall induced by typhoons. The development and application of forecasting techniques for heavy rainfall are summarized in terms of numerical weather prediction techniques and objective forecasting methods. Greatly aided by the rapid progress in meteorological observing technology and substantial improvement in electronic computing, studies of heavy rainfall in China have advanced to investigating the evolution of heavy-rain-producing storms and observational analysis of the cloud microphysical features. A deeper and more systematic understanding of the synoptic systems of importance to the production of heavy rainfall has also been developed. Operational forecast of heavy rainfall in China has changed from subjective weather event forecasts to a combination of both subjective and objective quantitative precipitation forecasts, and is now advancing toward probabilistic quantitative precipitation forecasts with the provision of forecast uncertainty information. 相似文献
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R. Suppiah 《Climate Dynamics》1994,10(8):395-405
Synoptic climatological patterns that produce anomalous wet conditions in central Australia during the period from September to April have been studied. The analysis was done by using observed daily rainfall data at a number of stations, wind and mean sea level pressure from the European Centre for Medium Range Weather Forecasts (ECMWF), Tropical Ocean and Global Atmosphere (TOGA) data from 1985 to 1991, and the CSIRO 9-level (CSIR09) global climate model (GCM) simulated data for 1 × CO2 and 2 × CO2 experiments. On the basis of rainfall values above 99.5 percentile in observed and simulated data, wet days have been selected to study the synoptic-scale weather systems that produce anomalous wet events in central Australia. As the vast majority of days in central Australia are dry, the same number of days with no rainfall for both observed and simulated conditions have been selected randomly. The observed synoptic climatological patterns have been compared with the results of the control simulation of CSIRO9. A comparison between CSIRO9 simulated synoptic patterns and observed synoptic patterns reveals that the model fairly well captures the synoptic climatological characteristics which produce anomalous wet and contrasting dry weather conditions during the period from September to April. Under enhanced greenhouse experiments, the main features of the synoptic patterns are intensified both for wet and dry conditions, which result in an increase in extreme weather conditions, an increase in rainfall intensity, a spatial expansion of the heavy rainfall region during wet days, and an expansion of the dry area during dry days. During anomalous wet conditions, the low pressure area is intensified, monsoonal winds and southeasterlies are strengthened and strong wind shear over tropical Australia is simulated. During this condition, the monsoon shear line moves poleward particularly over the Northern Territory. In contrast, during dry conditions, the anticyclonic circulation over the continent is strengthened. 相似文献
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闽中北短时暴雨概念模型 总被引：5，自引：1，他引：4
通过对福建中北部35个站1994～2001年97次暴雨过程的环流背景、影响系统等进行分析,将天气类型分为冷式切变(或槽)影响型、西南气流影响型、副高型(Ⅰ～Ⅱ型),归纳总结了各天气型的雷达回波源地、加强区域、路径、演变及降水特征,建立了天气图等常规资料与雷达回波资料相结合的闽中北短时暴雨3种概念模型。Ⅰ、Ⅱ型的降水强度总体相差不很大,有西南风急流比没有时降水强,Ⅱ型尤其明显,Ⅲ型降水强度最弱、持续时间最短。 相似文献
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Michael J. Pook James S. Risbey Peter C. McIntosh 《Theoretical and Applied Climatology》2014,117(3-4):521-533
Two distinct synoptic weather systems, cut-off lows and fronts, deliver most of the cool-season rainfall to the cropping regions of southern Australia. A comparative synoptic climatology of daily rainfall events over approximately five decades reveals both spatial and temporal variations of the dominant synoptic types. The rainfall characteristics and associated large-scale drivers differ between the two synoptic types. Understanding regional rainfall depends on understanding these differences. Cut-off lows contribute one half of growing season rainfall in southeast Australia, while frontal systems associated with Southern Ocean depressions contribute about a third. The proportions are reversed in the Central Wheat Belt (CWB) of Western Australia where Southern Ocean fronts are the dominant source of growing season rainfall. In the southern island state of Tasmania, topography strongly influences the outcome with cut-off lows contributing about half the rainfall near the east coast and fronts dominating a short distance to the west. Cut-off lows generally contribute their highest proportion of rainfall in the austral autumn and spring while frontal rainfall is at its maximum in late winter. Cut-off low rainfall contributes more strongly in percentage terms to the recent decline in rainfall. The distribution of synoptic types is explained by the dominant long-wave structure in the winter half of the year. The major trough near Western Australia favours frontogenesis to the southwest of the CWB but fronts moving out of the region encounter a persistent meridional ridge in the Tasman Sea where there is a high frequency of blocking events. 相似文献
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该文总结回顾了中央气象台近年来的天气预报业务技术进展。天气预报质量的历史演变显示了预报业务水平的提高, 这种业务能力的提高既反映了预报技术的发展, 也带来了天气预报业务的变化。对业务天气预报中各种预报技术应用进展的分析表明:数值预报在天气预报业务能力提高中发挥着重要的基础性作用; 同时, 基于对不同尺度天气影响系统发展演变过程深入认识的基础上, 天气学的预报方法依然是预报业务中的重要技术方法; 动力诊断预报已成为灾害性天气预报中的重要手段之一, 数值预报产品的解释应用是实现气象要素精细定量预报的技术途径。 相似文献
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