2012年11月35日华北地区出现了该年度的第一次大范围雨雪天气过程，各地区依次都出现了雨转雪的复杂天气，这给预报带来了较大的难度。一直以来，冬季降水相态类型的预报都是国内外气象预报的难题之一，而温度的垂直结构特征是影响最终降水类型的关键因素之一。利用常规地面观测资料、NCEP再分析资料及中尺度数值模式WRF对此次雨雪天气过程中的温度垂直结构演变特征以及相态转变对温度垂直结构的作用等几个方面进行了分析讨论。结果表明：（1）在发生雨转雪过程中，温度递减率会持续减小，并最终会在低层形成一个上下一致的均温层，同时还伴有浅薄逆温层的产生；（2）降水相态类型严重依赖于温度的垂直结构，温度垂直结构的细微改变将决定最终到达地面的降水类型，因此，相关层次的厚度差可以成为判别降水相态类型的重要指标；（3）在降水类型由雨转雪的过程中，由于相关层次的融化作用，伴随着相态的变化温度垂直结构会发生一定程度的改变。
The large-scale rain or snow process took place in North China firstly and the type of precipitation began to change from rain to snow orderly from 3 to 5 November 2012. It is very difficult to forecast. At the same time, the thermal vertical structure is a critical factor in determining the precipitation type. The analyses of the interrelation between the thermal structure and precipitation type was done. The results show that the fine distinction of thermal structure determine the final type of precipitation which fall on surface. Moreover, in the transition process from rain to snow the thermal vertical structure will change due to the melting effect while the frozen precipitation aloft fall.
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