2015年1月鄂西北东部一次暴雪天气过程的诊断分析

Diagnostic Analysis of a Snowstorm Weather Process in January of 2015 over the Eastern Part of Northwest Hubei Province

摘要: 利用常规观测资料、NCEP 1˚ × 1˚ FNL资料对2015年1月27~28日鄂西北东部的一次暴雪过程进行诊断分析，结果表明：高空东移槽、中低层切变线、低空急流与地面冷空气是主要的影响系统，边界层辐合与高层辐散的增强，有利于低层上升运动增强，从而触发了不稳定能量不断释放；中低层正涡度与高层负涡度的稳定维持，促使低层气旋性涡度环流增强，这为暴雪提供了动力条件，冷暖空气稳定对峙，造成暴雪持续，暴雪发生700 hPaMPV1强中心与MPV2绝对值迅速增大的重叠区域。

Abstract: Diagnostic analysis of a blizzard process on 27 - 28 January 2015 over the eastern region of northwest of Hubei Province based upon the observational data and 1˚ × 1˚ FNL data from the NCEP reanalysis center. Results show that the upper-level eastward trough, mid-level shear line, low-level jet, convergence of boundary layer and upper-level divergence cause intensified vertical motion and release of unstable energy. Stable condition of mid-level positive vorticity and upper-level negative vorticity will intensity the low-level cyclonic circulations. These provide a favorable dynamical condition for such blizzard. Meanwhile, the rapid intensification of 700 hPa MPV1 and MPV2 is in accordance with the place where such blizzard occurs.