关键词: 陇南, 陇南, 杭州, 龙井茶, 气候要素, 对照分析

Abstract: To reduce the damage of agriculture caused by the squall line weather, the information-baseSdata from 1979 to 2013 from Shanxi Meteorological Information Center and MICAPS data is used and statistical analysis of the squall line weather in Shanxi Province was done. The results show that: The spatial distribution characteristic presents that the days of squall line is more in the east than in the west of Shanxi Province. Squall line mainly occurred among April to September, the highest frequency of squall line appears in June to July. The appearance of squall line weather has obvious diurnalSvariationSfeatures and the largest incidence of squall line is during 16:00-17:00 o’clock. Days and stations of the squall line in Shanxi reduced with the rate of 3.6 days every 10 years nearly 35 years. There are four main types of conceptual models of squall line in Shanxi. They are respectively the model of low vortex with cold front, low vortex without cold front, westerly trough with cold front, and westerly trough without cold front. Four types of concept model are all combined with low-level cold or warm shear line. Which kind of severe convective weather will happen while the squall line transits depends on the humidity conditions of low layer. Short-time heavy rain will happen when the low level is matched with moist tongue, and gale and downbursts will happen when the low layer is controlled by dry tongue. When the depression of the dew point of low layer is greater than 6 ℃ and less than 11 ℃, it is often accompanied by thunderstorm and hail.