Analysis of Predictability on a High-Altitude Hail/Graupel Disaster Weather in Nanjing Airspace

Abstract

Synoptic analysis,radar observation and numerical simulation are used to analyze a convection weather process occurred in Nanjing airspace on 10 August 2011 w hich causing aero damage. All analysis support a deduction that this damage caused by hail strike,but there w as no hail observed on the ground. Since hail generates on high level of about thousands of meters,it may melt in the falling process and rain on the ground. Nanjing w as northw estw ard to the subtropical high pressure zone and in the southw est flow before the trough of Hetao low pressure area at that day. It w as near a low level shear line and had sufficient convective potential condition.Dry cold air distributed on upper level and w arm w et air distributed on low er level. This structure is benefit to the generation of hail. Analysis of radar observation show s that this convective system developed very high. Reflectivity in the core w as very strong. VIL and hail index all had high value. And there w ere meso-cyclone and middle altitude radial convergence in this system. The dynamic and flow structure of this system w ere corresponding to typical hail storm. This paper indicates that this high-altitude hail process w as obviously predicted.