Influence of the Maintenance of Upper Jet Stream on Snowstorms in the Southern Part of China

The effects of the kinetic energy of upper jet disturbances on snowstorms on 9 February 2014, 5 December 2015, 20 January 2016, and 20 January 2018 were analyzed using ERA-Interim data. During snowstorms, an upper jet is usually present, causing vertical upward motion that aids in developing the snowstorm. The vertical motion serves two purposes. First, it transports warm and moist air at a low level to a high level, thus providing a continuous stream of water vapor for snowstorms. Second, it transports the kinetic energy of the jet disturbances downward to a intersection area of warm and cold air at a low level. This area exhibits wind shear that provides the kinetic energy of the disturbance to the local area and further promotes the occurrence and development of snowstorms.