2024年2月初,受持续性冷空气影响,湖南邵阳地区出现了较为罕见的持续性低温雨雪冰冻天气,邵阳市区和邵东48 h最低气温降幅达7.5℃以上,2月2日至7日全市平均气温0.9℃,较历年同期(6.5℃)偏低5.9℃。对EC模式预报产品检验分析发现,最新起...2024年2月初,受持续性冷空气影响,湖南邵阳地区出现了较为罕见的持续性低温雨雪冰冻天气,邵阳市区和邵东48 h最低气温降幅达7.5℃以上,2月2日至7日全市平均气温0.9℃,较历年同期(6.5℃)偏低5.9℃。对EC模式预报产品检验分析发现,最新起报时次的各层温度0线、逐3小时和逐6小时降雪量,对预报雨雪相态转换以及降雪落区具有很好的指示作用。在本轮过程中700 hPa 0℃线南压至邵阳是降水相态转为雪的重要经验指标,降水相态为冻雨时的850 hPa温度和地面温度低于雨夹雪。双偏振雷达CC、ZDR与KDP产品在本次低温雨雪过程中对降水相态的判定有较为明显的指示作用。In early February 2024, due to the continuous cold air, Shaoyang area in Hunan Province experienced a rare sustained low-temperature rain, snow, and freezing weather. The minimum temperature in Shaoyang city and Shaodong decreased by more than 7.5˚C in 48 hours. From February 2nd to 7th, the city’s average temperature was 0.9˚C, which was 5.9˚C lower than the same period in previous years (6.5˚C). The inspection and analysis of EC model forecast products found that the zero temperature line at each layer and the snowfall amount every 3 hours and 6 hours at the latest evening are good forecast indexes for forecasting the phase of rain and snow and the transformation of snowfall regions. In this round, the southward pressure of the 700 hPa 0˚C line to Shaoyang is an important empirical indicator for the transition of precipitation phase to snow. When the precipitation phase is freezing rain, the 850 hPa temperature and ground temperature are lower than those of sleet. The products of dual-polarization radar CC, ZDR and KDP have obvious indication function on the judgment of precipitation phase in the process of low temperature rain and snow weather.展开更多
基于NCEP再分析资料、EC资料和常规观测资料,应用天气分析和诊断分析方法,对2016年1月广西的低温雨雪天气进行了分析,结果表明:(1)此次低温雨雪天气与阻塞高压的强而稳定密切相关。冷空气之强盛为历史所罕见,与历史同期相比,地面冷高压...基于NCEP再分析资料、EC资料和常规观测资料,应用天气分析和诊断分析方法,对2016年1月广西的低温雨雪天气进行了分析,结果表明:(1)此次低温雨雪天气与阻塞高压的强而稳定密切相关。冷空气之强盛为历史所罕见,与历史同期相比,地面冷高压显著偏强,850 h Pa的0℃线明显偏南。850 h Pa华南强锋区的长时间维持,是造成此次过程的重要原因之一。(2)雨夹雪与雪的条件相似,主要是温度垂直结构存在差异;而降雪与降雨相比,温度垂直结构、云顶高度、逆温层顶部气温以及暖层的厚度、高度、强度、地面气温均有明显的区别。(3)降水相态由雨转为雪时,广西上空的锋面垂直结构有明显的变化。(4)持续而强盛的水汽输送、湿层深厚有利于阴雨、雪天气的发生及持续。相关分析结论可为广西低温雨雪冰冻预报提供技术参考。展开更多
文摘2024年2月初,受持续性冷空气影响,湖南邵阳地区出现了较为罕见的持续性低温雨雪冰冻天气,邵阳市区和邵东48 h最低气温降幅达7.5℃以上,2月2日至7日全市平均气温0.9℃,较历年同期(6.5℃)偏低5.9℃。对EC模式预报产品检验分析发现,最新起报时次的各层温度0线、逐3小时和逐6小时降雪量,对预报雨雪相态转换以及降雪落区具有很好的指示作用。在本轮过程中700 hPa 0℃线南压至邵阳是降水相态转为雪的重要经验指标,降水相态为冻雨时的850 hPa温度和地面温度低于雨夹雪。双偏振雷达CC、ZDR与KDP产品在本次低温雨雪过程中对降水相态的判定有较为明显的指示作用。In early February 2024, due to the continuous cold air, Shaoyang area in Hunan Province experienced a rare sustained low-temperature rain, snow, and freezing weather. The minimum temperature in Shaoyang city and Shaodong decreased by more than 7.5˚C in 48 hours. From February 2nd to 7th, the city’s average temperature was 0.9˚C, which was 5.9˚C lower than the same period in previous years (6.5˚C). The inspection and analysis of EC model forecast products found that the zero temperature line at each layer and the snowfall amount every 3 hours and 6 hours at the latest evening are good forecast indexes for forecasting the phase of rain and snow and the transformation of snowfall regions. In this round, the southward pressure of the 700 hPa 0˚C line to Shaoyang is an important empirical indicator for the transition of precipitation phase to snow. When the precipitation phase is freezing rain, the 850 hPa temperature and ground temperature are lower than those of sleet. The products of dual-polarization radar CC, ZDR and KDP have obvious indication function on the judgment of precipitation phase in the process of low temperature rain and snow weather.
文摘基于NCEP再分析资料、EC资料和常规观测资料,应用天气分析和诊断分析方法,对2016年1月广西的低温雨雪天气进行了分析,结果表明:(1)此次低温雨雪天气与阻塞高压的强而稳定密切相关。冷空气之强盛为历史所罕见,与历史同期相比,地面冷高压显著偏强,850 h Pa的0℃线明显偏南。850 h Pa华南强锋区的长时间维持,是造成此次过程的重要原因之一。(2)雨夹雪与雪的条件相似,主要是温度垂直结构存在差异;而降雪与降雨相比,温度垂直结构、云顶高度、逆温层顶部气温以及暖层的厚度、高度、强度、地面气温均有明显的区别。(3)降水相态由雨转为雪时,广西上空的锋面垂直结构有明显的变化。(4)持续而强盛的水汽输送、湿层深厚有利于阴雨、雪天气的发生及持续。相关分析结论可为广西低温雨雪冰冻预报提供技术参考。
