Based on the high spatial and temporal resolution detection data of the array weather radar (AWR) at Changsha Huanghua Airport, and the minutely precipitation observation data of four regional automatic weather stations, the evolution of echo characteristics of two convective events occurring near the airport on 20 May 2018 and 1 August 2018 were analyzed, and the effective potential energy per unit area was used to analyze the two events. The results show that the AWR could provide fine data for the study on the development of the short-time severe precipitation. The convective process on 1 August 2018 was a short-term strong convection process without a significant downdraft, and there was no significant convergence and divergence near the ground, and the effective potential energy release ratio per unit area was far less than 30%. The convective process on 20 May 2018 produced a local downdraft with the surface maximum wind speed of 11.6 m·s-1, and the release ratio of equivalent potential energy per unit area was over 30%. The storm began to develop near the 0 ℃ layer of the atmosphere and formed several storm cells. The coalescence growth of the storm cells led to form a new storm and accelerated the development of the new storm. The mid-level radial convergence and near-surface divergence of the echo were consistent with the wind speed and wind direction changes of the surface automatic meteorological station. The increases of the dew point temperature and pressure from automatic weather station had a certain indicative effect on the downdraft of storm. The AWR provided the warning information of 13 minutes before the surface wind speed reaching its maximum value, and improved the monitoring and early warning on short-time small-scale weather systems such as downbursts by analyzing the effective potential energy release ratio per unit area.

By using meteorological observation data from eight weather stations in Southwest Guizhou and Micpas data and NCEP reanalysis data in recent five years， the spatial and temporal distribution of fog weather in Southwest Guizhou was analyzed in this paper． The results show that the main synoptic patterns resulted to fog weather here were the westerly flow in front of the southern trough and the northwest flow behind the upper trough，and physical quantity fields analysis indicated that the low － level air was wet when frontal fog appeared，and the atmosphere structure was relatively stable，there was a temperature inversion layer in lower level，and a weak upward motion nearby frontal area．