Impact of Cyclonic Storm “Sitrang” over the Bay of Bengal on Heavy Rain and Snow in Eastern Tibet
Xiaotao Zhao,
Lunzhu Danzeng,
Qu Chi,
Xulin Ma,
Yuting Tan,
Luozhu Duodian,
Ranzhen Danzeng
Affiliations
Xiaotao Zhao
Key Laboratory of Meteorological Disaster, Ministry of Education/International Joint Research Laboratory of Climate and Environment Change, Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters, Nanjing University of Information Science and Technology, Nanjing 210044, China
Lunzhu Danzeng
Meteorological Observatory of Tibet Autonomous Region, Lhasa 850000, China
Qu Chi
Meteorological Observatory of Tibet Autonomous Region, Lhasa 850000, China
Xulin Ma
Key Laboratory of Meteorological Disaster, Ministry of Education/International Joint Research Laboratory of Climate and Environment Change, Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters, Nanjing University of Information Science and Technology, Nanjing 210044, China
Yuting Tan
Key Laboratory of Meteorological Disaster, Ministry of Education/International Joint Research Laboratory of Climate and Environment Change, Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters, Nanjing University of Information Science and Technology, Nanjing 210044, China
Luozhu Duodian
Meteorological Observatory of Tibet Autonomous Region, Lhasa 850000, China
Ranzhen Danzeng
Meteorological Observatory of Tibet Autonomous Region, Lhasa 850000, China
Rainstorms and blizzards are common extreme weather events occurring in the eastern Tibet region. Their complex dynamic and thermodynamic mechanisms present challenges for regional meteorological research and forecasting. Based on station observation data and ERA5 atmospheric reanalysis datasets, a diagnostic analysis of the heavy rain and snow event in eastern Tibet from 24 to 27 October 2022 was conducted. The results indicate that (1) the influence of the cloud systems surrounding the Bay of Bengal storm “Sitrang” was a significant factor contributing to the occurrence of this heavy rain and snow weather. (2) Sustained stability of the southern branch trough and the western Pacific subtropical high favored the establishment and maintenance of the mid-level jet stream ahead of the storm. Storm “Sitrang” transported warm and moist air to eastern Tibet through the southwest mid-level jet stream, providing favorable moisture, dynamic, and thermal conditions for the heavy rain and snow. (3) Most importantly, symmetrical instability generated by the inclined motion of the storm’s warm and moist air emerged as the decisive mechanism driving the occurrence and development of the heavy rain and snow.
