The dominant synoptic patterns and basic characteristics of regional snowstorms in Northern Xinjiang over the past 70 years.

This study employs the PCT objective classification method to analyze 134 regional snowstorm events in northern Xinjiang (NX) during 1953-2022 using observational and reanalysis data, identifying four primary synoptic types that are all associated with polar vortex activity. This study investigated the snowstorm characteristics associated with the synoptic patterns, along with the features of upper- and lower-level jet streams and moisture transport. The results show that 66.4% of cases are related to eccentric polar vortex patterns while 33.6% are connected to dipole vortices, with each synoptic type exhibiting distinct formation mechanisms. The research demonstrates that variations in upper- and lower-level jets directly influence snowstorm frequency and spatial distribution, while also affecting moisture transport characteristics. Moisture is primarily transported into the region through western boundaries and out through eastern boundaries, with significant additional input from northern boundaries, patterns that are fundamentally determined by differences in large-scale circulation systems. These findings provide important insights into the atmospheric dynamics governing snowstorm formation in NX.