A group of 6 delegates from Central and Southern Region, ATMB, CAAC visited the Observatory between 25 and 27 October 2011.  The Observatory introduced to them the latest developments of aviation weather service in Hong Kong, including meteorological instrumentation, windshear and turbulence alerting service, convective weather forecast, personnel training and international developments.  ATMB colleagues also visited the Observatory's Airport Meteorological Office, a LIght Detection And Ranging (LIDAR) site and Terminal Doppler Weather Radar.  In return, they made a presentation on the present status and new developments of ATMB, CAAC, such as enhancement of weather monitoring along the flight routes and implementation of Collaborative Decision Making (CDM).  The visit was useful for experience sharing between the two organizations on the provision of aviation weather service.