【摘要】 利用常规气象探测资料、NCEP 1°×1°再分析资料和清远市连州市双偏振雷达资料,对粤北2018年1月8日隆冬冷空气诱发的暴雨和雨雪相态转变进行过程分析。结果表明:横槽转竖,引导冷空气南下,中低层逆温层明显,近地面层温度<0℃,地面温度<1℃,粤北部分地区地面气温降至0℃以下,这是雨雪相态复杂转变的主要原因;近地面偏北急流和低层西南急流的叠加作用,西南低空急流长时间维持和加强,加强了Ekman抽吸作用,导致该次暴雨的形成。协相关系数(ρ_HV)可识别融化层,能抓住融化层的快速变化。粒子相态分类产品（HCL）能快速呈现降水粒子的相态变化,但对于雨夹雪不能很好的识别。更多还原

【Abstract】 Using conventional meteorological observations, NCEP 1°×1°reanalysis and dual-polarization radar data from Lianzhou, Qingyuan, this paper studies a hard rain induced by cold air in northern Guangdong and phase transition between rain and snow on January 8, 2018, in the prime time of winter. The result is shown as follows. As a transverse trough turns upright, cold air is steered to head south and inversion in the middle and lower atmospheric layers becomes significant, with the temperature <0℃ in the near-surface layer and <1℃ at the surface. Surface air temperature drops to below 0℃ in part of the northern Guangdong. These are the primary causes for the complicated phase transition between rain and snow. As a near-surface northerly jet stream is superimposed with a low-level southwesterly jet stream, the latter is maintained and intensified for extended time to increase the Ekman sucking effect, resulting in the occurrence of the hard rain of interest. Co-correlation coefficient(ρHV) can identify the melting layer and its rapid variation. HCL, a particle category product, rapidly shows the phase transition of precipitating particles, but it does not capture sleet as well.更多还原