Spatial and temporal distribution characteristics of severe convection weather in Inner Mongolia

Based on the daily observational data of thunderstorm, hail, strong wind at 119 stations in Inner Mongolia from 1985 to 2013, the spatiotemporal distribution characteristics and variation of thunderstorm, hail, and thunderstorm wind were studied using mathematical statistics and correlation analysis. The results are as follows. (1) The distribution patterns of the three kinds of severe convection weather in Inner Mongolia exhibit a north to south direction along the Daxinganling mountains in the east, and an east to west direction along the Yinshan mountains in the west. The three severe weather systems mainly occur in Ordos, Baotou, Hohhot, Wulanchabu, XilinGol League, and Chifeng.(2) The annual average thunderstorm days in the multi-thunderstorm centers reach up to 30 d. The annual average hail days in the multi-hail centers reach up to 1.4 d. The annual average thunderstorm wind days in multi-thunderstorm wind centers reach up to 3.5 d. (3) The three kinds of severe convection weather systems in Inner Mongolia present significantly seasonal variations, of which thunderstorm, hail, and thunderstorm wind occur the most in summer. (4) They all present decreasing trends with time. Their active months present a tendency of single-peak distribution. The active period of thunderstorm, hail and thunderstorm wind concentrates in the months from May to September. Most thunderstorms occur in July, with about 8 d per station. Hail occurs the most in June, with about 0.3 d per station. Thunderstorm wind occurs the most in June, with about 0.89 d per station.