2023年5月巴州北部平原极端低温天气成因及可预报性分析
Causes and Predictability of Extreme Low-temperature Weather in the Northern Plain of Bazhou in May 2023
周雪英 1张云惠 2仇会民 1杨柳 1刘长墉1
作者信息
- 1. 巴音郭楞蒙古自治州气象局,新疆 库尔勒 841000
- 2. 新疆气象台,新疆 乌鲁木齐 830002
- 折叠
摘要
利用常规观测、1日 4 次FNL1°×1°、NCEP2.5°×2.5°再分析等资料,探讨 2023年 5 月2-7日巴州北部平原极端低温雨雪天气成因及可预报性.结果表明:(1)极端低温雨雪天气发生在高层北半球极涡呈偏心型,500 hPa乌拉尔山阻塞高压发展、深厚中亚低涡在新疆长时间维持的环流背景中,低涡持续时间和冷中心强度对天山南坡的影响在 5月实属罕见.(2)较强冷空气自西北路径翻越西天山进入南疆盆地,与南疆盆地东灌冷空气在巴州北部汇合增强,降水落区位于低层暖平流中心和850 hPa锋生区域,雨转雪加剧巴州北部平原最低气温的降幅.(3)EC模式形势预报提前 96h对中亚低涡的可预报性差,72 h内能较准确刻画低涡强度、位置和移动路径,但细节存在偏差;对最低气温预报EC模式稳定、准确,具有极强参考价值;对库尔勒城区降水和雨雪相态预报,智能网格及NCEP、EC、CMA-GFS数值模式预报能力有限.
Abstract
Using conventional observation,FNL 1°×1°and NECP 0.25°×0.25° for 4 times one day reanalysis data and other data to explore the causes and predictability of extreme low-temperature rain and snow weather in the northern plain of Bayingolin Mongolian Autonomous Prefecture(Bazhou for short)from May 2nd to 7th,2023.The results showed that:(1)extreme low-temperature rain and snow weather occurred in the upper northern hemisphere with an eccentric polar vortex.In the circulation background of 500 hPa Ural Mountain blocking high pressure development and long-term maintenance of deep Central Asian low vortices in Xinjiang,the impact of low vortex duration and cold center intensity on the southern slope of Tianshan Mountain was rare in May;(2)the strong cold air crossed the western Tianshan Mountains from the northwest path and entered the southern Xinjiang basin.It merged with the cold air from the eastern part of the southern Xinjiang basin and strengthened in the northern part of Bazhou.The precipitation area was located in the center of the low-level warm advection and the 850 hPa frontogenesis area,and the change from rain to snow exacerbated the decrease in the minimum temperature in the northern plain of Bazhou;(3)the EC model had poor predictability for the Central Asian low vortex when predicting the situation 96 hours in advance,and could accurately depict the strength,position,and movement path of the low vortex within 72 hours,but there were deviations in the details;the EC model for predicting minimum temperature was stable,accurate,and had strong reference value;the intelligent grid and NCEP,EC,and CMA-GFS numerical models had limited predictive capabilities for precipitation and snow phase prediction in the urban area of Korla.
关键词
巴州北部平原/极端低温/天气成因/可预报性Key words
northern plain of Bayingolin Mongolian Autonomous Prefecture/extreme low-temperature/weather causes/predictability引用本文复制引用
基金项目
新疆维吾尔自治区重点研发任务专项(2022B03027-1)
新疆维吾尔自治区重点研发任务专项(2022B01012-1)
新疆气象局创新发展面上项目(202301)
出版年
2023
国家科技期刊平台
NSTL
维普
万方数据