Abstract：Through analysing the phenomenon record of Squall in recent 30 years in RuYuan County, we got the result that annual average of Squall phenomena is 1.3d. Since the 90’s, there is a tendency of significant decline, occuring mainly in Mar. to Sept.. July is the most, reaching 11d. Summer accounted for 57.5% while none in Winter. The distribution is more in Spring & Summer and less in Autumn & Winter. Normally Squall occurs in daytime (08:00~20:00), accounting for 87.5% of the total frequency. During 15:00~19:00, Squall phenomena reaches 62.5%, in 15:00, 17:00, 18:00 Squall frequency reaching to 15% as highest. Moreover there are Convective weather like Thunderstorms, lightning, rain or hail following. Combining the practical business, we propose how to avoid wrong report & missing strategy of Squall phenomenon so that we can improve the level forecast squall phenomena.
2011, Vol. 28 
