2013年5月18日兰州北部强雷暴过程分析

A Process Analysis about the Thunderstorm Happened in the North of Lanzhou on May 18,2013

利用气象常规资料、Doppler雷达资料、NECP 2.5°×2.5°再分析资料对2013年5月18日发生在兰州北部一次强雷暴天气过程进行分析。结果表明,此过程发生在中川机场的冰雹为主要强对流天气,并相继造成永登、两当等地的强降水,大风天气;主要影响系统为地面冷锋、高空冷槽、高空急流;在极为有利的高低空系统配置下,暖湿空气遭遇干冷气流后剧烈抬升,环境风场对上升运动进一步加强,-20℃层高度适宜,有利于产生冰雹。

By using conventional meteorological data, Doppler radar data, NECP 2.5°× 2.5° reaualysis data, the thunderstorm process hap-pened in the north of Lanzhou on May 18, 2013 was analyzed. The resuhs showed that hail was main convective phenomenon, and this thunder-storm caused rainfall in Yongdeng, strong wind in Liangdang in succession. Main influence system included coht front, cold trough and jet stream. Under the extremely beneficial vertical system configuration, moist air in a sharp rise after encountering dry air, envirotmlental wind field was further strengthen on upward movement, and -20 ℃ layer height is appropriate and is helpful to produce hail.