88th Annual Meeting (20-24 January 2008)

Wednesday, 23 January 2008
TDWR-LIDAR dual Doppler analysis of 2D wind field associated with subtropical squall lines
Exhibit Hall B (Ernest N. Morial Convention Center)
P. W. Chan, Hong Kong Observatory, Hong Kong, China; and A. M. Shao
Poster PDF (1.9 MB)
Located in a subtropical area, Hong Kong is often affected by squall lines in the spring and summer time. The squall lines could bring about high wind gusts and have complex distribution of horizontal wind in the lower troposphere, such as micro-scale vortices and jets. When the squall line just arrives at Hong Kong, the rain may not be too heavy so that both the Observatory's Terminal Doppler Weather Radar (TDWR) and LIDAR could have good simultaneous measurements of the low-level winds in the vicinity of the Hong Kong International Airport. This paper examines the complex horizontal wind distribution in the lower boundary layer as revealed in TDWR-LIDAR dual Doppler analysis for two typical squall line cases. The analysis is found to reveal many salient features of the wind. In particular, the jets tend to occur around the micro-scale vortices and bow-echo apices. With proper quality control of the TDWR and LIDAR data, the dual Doppler analysis has the potential to assist the forecasters in monitoring the high wind gusts in squall line events.

Supplementary URL: