Abstract: Based on conventional radiosonde observations and analysis data of Weather Research and Forecast (WRF) model,the climatic background characteristics,evolutional feature and diurnal variation of severe convective weather in Shenyang from 2005 to 2014 were investigated.Severe convective weather was classified into four types,including hailstorm,thunderstorm and strong wind (≥17.2 m·s^-1),short-time strong rainfall (≥20 mm·h^-1),and the mixture of all.The function of the radiosonde data in the potential forecast of severe convective weather was analyzed,particularly that at 14:00 (02:00) in the short-term potential forecast of severe convective weather in Shenyang.The results show that the short-time strong rainfall among severe convective weather types occur mostly in Shenyang from 2005 to 2014,followed by thunderstorm and strong wind,and hail ranks the last.Severe convective weather mostly occurs in the afternoon towards the evening.Analysis of profiles of air temperature and humidity in T-LogP diagrams indicates that the short-time strong rainfall events usually accompany with significant moisture area in the middle and lower atmosphere,which are very different from those of thunderstorm,strong wind and the hailstorm.The latter three types show a dry layer in the middle atmosphere from the most of T-LogP diagrams.The heights of layers of 0℃ and -20℃ for hail are obviously lower than those of the other convective weather types.Temperature difference between 700 hPa and 500 hPa (T₇₀₀-T₅₀₀) and that between 850 hPa and 500 hPa (T₈₅₀-T₅₀₀) of hail weather are significantly larger than those of short-time strong rainfall,thunderstorm and strong wind,and the value of T₈₅₀-T₅₀₀ has better referential meaning.The mean value of Showalter index (SI) for the four types of severe convective weather is positive,which means that SI has no meanings.The K-index value of short-time strong rainfall weather is significantly greater than that of hail weather,and the convective available potential energy (CAPE) of thunderstorm and strong wind is significantly smaller than that of the other types.The predicted T-LogP diagram from the WRF model has a certain reference for the forecast of severe convective weather in Shenyang.

Key words: Severe convective weather, Short-term potential forecast, Environmental parameter, T-LogP diagram, Meso-scale Weather Research and Forecast (WRF) model