Abstract:
From 2018 to 2020,thunderstorm gales in Tianjin were documented using AWS,lightning location data,FNL data,and Doppler radar data during the flood season.The results indicated that:(1)The thunderstorm gales in Tianjin mostly occur in the northern mountains and eastern coastal areas from June to August and during the first half of the night.(2)The weather patterns are classified into four types:subtropical high periphery,cold vortex,low trough,and northwest airflow.The cold vortex type is the most common.(3)The convective storms are classified into five types:multicell cluster storm,multicell line storm,squall line,bow echo,and single-cell storm.The squall line and bow echo are the main types that cause extreme values for thunderstorm gales.(4)The possibility of thunderstorm gales is highest when the maximum reflectivity factor is around 61 dBZ,and the falling rate of the strong echo center is around 260 m·min
-1.(5)By analyzing large value areas of radial velocity at lower levels ahead of time by 30 minutes warning intervals can be provided for approximately 15.4%multicell cluster storms,14.3% multicell line storms as well as 22.2% squall line-induced thunderstorm gales.