湖南罕见的一次低温雨雪冰冻灾害天气分析及预警预报

A Synoptic Analysis and Warning Forecast of an Unprecedented Severe Cold Surge, Freezing Rain and Snow Disaster in Hunan

2008年1月中旬至2月初,湖南出现历史上罕见的低温、雨雪、冰冻灾害天气。对此次冰冻灾害进行了分析并与历史同期进行了比较,结果表明:此次冰冻灾害天气的主要特征是影响范围广、持续时间长、灾害强度大。"拉尼娜"事件和大气环流异常为此次持续的灾害性天气提供了重要的气候背景,在此背景下欧亚大气环流的持续稳定则是此次湖南持续低温雨雪灾害的直接原因。通过对这次冰冻灾害的成因分析,得出了冰冻预报的着眼点,提出了各级气象台站如何做好预报预警服务的基本思路,为冰冻灾害天气的准确预报、预警服务提供参考,对各级台站重大灾害性天气的预报服务和应急响应,具有重要的指导意义。

Extreme low temperature, heavy snowstorm and frozen weather occurred in Hunan in January, 2008. The disaster was reviewed and compared with other frozen weather, showing： this disaster had national-wide influences, long-lasting period and high intensity. La Nina event and anomalous atmospheric circulation provided important climate background for the severe weather. The stable atmospheric circulation of Eurasian was considered as the direct reason of the severe freezing rain and snow storms. After that the reason of frozen rain process was analyzed, the key points for forecasting freezing rain were obtained, and how should all levels observatories do for better forecast and early warning services were posed, so that references were provided for frozen rain forecast and warning service. These have significance for forecasting severe weather and emergency response of all levels observatories.