Study on evolution characteristics of temperature and humidity of two different thunderstorms in Kunming Airport

Based on the observation data of a ground-based microwave radiometer, the temperature and humidity distribution and evolution characteristics of two different thunderstorm events at different development stages at Kunming Changshui International Airport were studied. The conclusion are as follows. (1) 40 minutes before the thunderstorm forced by weather scale, the temperature and humidity profiles show that the low-level atmosphere temperature decreases but the water vapor density increases. They finally tend to be stable after the thunderstorm. This change can imply the start and end of convective activity. However, from 8 h to 40 min before the local thermal thunderstorm, the low temperature continued to rise and the water vapor density increases rapidly half an hour before the precipitation, which reflected the process of unstable energy accumulation in atmosphere and the changes in water vapor before the convection explosion. (2) The integrated water vapor content (IWV) and liquid water path (LWP) increase sharply before precipitation. During the thunderstorm precipitation at the weather scale, IWV and LWP transform into each other with the increase and decrease of temperature. The drastic cooling in the low layer accelerates the conversion of water vapor to condensates, resulting in a further increase in precipitation intensity, corresponding to the decrease in IWV, which is converted into LWP and surface precipitation. During thermal thunderstorm precipitation, the temperature changes uniformly, IWV and LWP increase uniformly, the amount of water vapor conversion is extremely small, and the increment of IWV is much higher than the actual precipitation. (3) Atmospheric precipitable water (PW) increased significantly half an hour before the two types of precipitation events. The total increase before the thunderstorm precipitation under the weather scale is 14.6 mm, and the PW increased evenly by 7.6 mm before the local thermal thunderstorm precipitation event.