ISSN 1000-0526
CN 11-2282/P
CN 11-2282/P
Archive > Volume 42 Issue 3 > 2016,42(3):280-293. DOI:10.7519/j.issn.1000-0526.2016.03.003 Prev Next
Analysis on Environmental Conditions and Structural Features of Typical Convective Tornado Storm in Meiyu Period
- Article
- Figures
- Metrics
- Preview PDF
- Reference
- Related
- Cited by
- Materials
Abstract:
By reanalysis data (1°×1°) 4 times a day from FNL/NCEP, Doppler radar, and automatic weather station (AWS), this paper analyzed the formation and structure characteristics of the convective storms which resulted in tornadoes from Anhui Tianchang to Jiangsu Gaoyou on 7 July 2013 after analyzing on environmental characteristics and feature extraction of convective parameters of tornadoes in Jiangsu Province in recent ten years’ Meiyu period. The results show that during the Meiyu period in YangtzeHuaihe Region, tornadoes are prone to occur in the right side of mesoscale cyclone (100 km), the lower right side of mesoscale vortex (200-300 km) and the left rear of lowlevel jet stream. General circulation in the Meiyu period provides plentiful moisture, favorable unstable stratification and dynamic conditions for tornadoes. The lowlevel cyclonic vorticity develops strongly before tornado. Vertical wind shear in boundary layer promotes cyclonic vorticity in tornado storm to strengthen rapidly, and enhancement of convergence in low troposphere is conducive to initialization of convection. As for tornadoes in Meiyu period, the demand to convective energy accumulation is lower than hails and thunderstorm gales. Bias between convective parameters feature value and climatic average value provides references for shortrange forecast of tornado. The tornado convective storm that triggered the tornado on 7 July 2013 initialized near surface convergence line. The strength of surface convergence and mesoscale frontal zone contributed to the development of convective storm. The series of tornadoes were produced by a longlife supercell storm which had echo characteristics of typical supercell. The mesocyclone inside the storm maintained two hours. Generally, the evolution of the mesocyclone parameters has great reference value to tornado warning, which shows that when the bottom height is low and shear values are significantly enhanced in the mesocyclone, tornadoes are more likely to occur.
Keywords:
Project Supported:
Clc Number:
Mobile website
