不同环流背景下极端高温天气特征和预报服务要点

Weather Feature and Service Points of Extreme High Temperature Under Different Circulation Situation

基于2013年和2017年湖北省2次极端高温过程中气象要素、NCEP再分析数据、灾情资料和服务材料等数据,对比分析2次高温重灾害年的环流背景、高温特征、主要影响和服务要点等方面的异同。结果表明,2017年环流指数明显偏强,高温来势猛、强度大,高温日平均有效积温值高,但前期降水正常,抗旱水源充足,造成损失小; 2013年副高控制湖北省中东部时间长,52站连续高温日数达到极端高温事件标准,同时,2011—2013年降水均低于历史平均值,且梅雨期降水偏少,持续高温和少雨导致重旱和特旱明显,经济损失为近10 a来最重。不同的天气背景导致高温的影响不同,重点服务方向有差别,2013年与抗旱增雨有关的决策材料占64%,而2017年更突出新媒体的应用,提供高温体验式预报服务,获得了较好的服务效果。通过对前期天气背景的分析和未来天气形势的预测,可以为气象服务的重点方向提供指导,有效加强灾害性天气服务针对性。

Based on meteorological elements,NCEP reanalysis data,disaster data and service data of two extreme high temperature processes in2013and2017in Hubei Province,the similarities and differences of circulation situation,characteristic and influence of high temperature and key points of service were analyzed.The results indicate that the circulation indexes in2017were larger than usual and the intensity of high temperature process was stronger with high effective accumulative temperature.Meanwhile,the precipitation was normal in the earlier period with enough water for drought resisting.Therefore the economic losses were small.In2013,subtropical anticyclone existed for a long time resulting in52stations reaching up to extreme high-temperature standard.Severe drought and extreme drought were obvious due to the less rainfall below the historical average value from2011to2013,and during Meiyu period in2013.The economic losses in2013were most serious in the last decade.The effects of high temperature and service orientations were different during the influencing period of different weather systems.The decision-making materials relating to drought resisting and rain enhancement made up64%in2013.While,new media and experiential forecast service which obtained the good service effect were the service highlight in2017.The analysis of weather situation in the earlier stage and weather forecast could provide guidance for emphasis orientations of meteorological service,and strengthen the targeted weather services effectively.