Characteristics of First Thunderstorm Caused by Warm Shear at Beijing Capital International Airport

Two first thunderstorms at Beijing Capital International Airport caused by warm shear was analyzed. The feasibility and success in forecasting the storms is also reported. The results can be summarized as follows: 1) During the two warm-shear thunderstorms, a shallow trough appeared at the 500 hPa level, and the time that the positive vorticity in the 500 hPa layer arrived at the airport was consistent with the timing of the thunderstorm. Furthermore, there was strong convergence in the lower uplift region. 2) From the radar images, it can be seen that an obvious convergence speed appeared near the airport, and the radar echo was generated locally when the thunderstorms occurred. 3) The lower the Black Body Temperture (TBB), the stronger the thunderstorms. Therefore, the convection development trend can be inferred from the TBB contour map. 4) During the thunderstorm periods, the thunderstorm index value from FY-2E satellite ranged from 0 to 0.5. The value accurately characterized the timings of the thunderstorms.