1951—2008年辽宁冰雹的时空分布特征

选取1951—2008年辽宁省56个站气象资料和中国气象灾害大典等资料,对冰雹时空分布进行统计分析。结果表明：辽宁冰雹日数以山地为最多,丘陵次之,平原和沿海最少。移动路径基本与山脉、河流、海岸线等地形走向一致。冰雹具有明显的季节变化,主要出现在4—10月。5—6月为冰雹多发期,6月为最多,5月次之。近30 a（1979—2008年）辽宁省年冰雹日数呈减少趋势。冰雹发生主要集中在中午至傍晚。辽西走廊、辽宁中部平原及辽东半岛南部大连地区为冰雹灾害重点防御区。产生冰雹的高空天气系统主要有4种：冷涡、冷涡后部横槽、高空槽和槽后西北气流,对应地面形势多为低压冷锋。

Temporal-spatial distribution of hall disaster from 1951 to 2008 in Liaoning province

Based on the data from 56 weather stations in Liaoning province from 1951 to 2008 and Chinese meteorological disaster dictionary,the temporal-spatial distribution of hail disaster was analyzed.The results indicate that the hail often happens in the mountains,followed by the hilly areas,then the plain and the coastal areas.The moving track of hail is identical to lay of the land such as mountains,river or coast line.The seasonal change of hail is obvious,and hail often occurs from April to October.Most hails happen in May and June,especially in June.The days of hail decease during the recent 30 years.Hail usually occurs from the noon to the evening.The key areas of hail prevention include Liaoxi corridor,the plain of midlle Liaoning and Dalian of southern Liaodong island.According to the high level situation classification,weather systems forming hail include cold vortex,cold vortex rear horizontal trough,high level trough and trough rear northwest air current,and the corresponding ground situation is low pressure cold front.