Backward Trajectory Map in August 2012

By using computer model analyses, the past 72-hour backward trajectory of the air mass reaching Hong Kong is estimated by the Observatory on a daily basis. The daily trajectories are compiled into the Monthly Backward Trajectory Map. The Monthly Map for August 2012 is now available on the following webpage:

http://www.weather.gov.hk/en/wxinfo/trajectory/trajectoryMonthly.shtml

In August 2012, except for a few days of continental airstreams brought about by tropical cyclones, the air masses reaching Hong Kong in the remainder of the month originated from the south and southwest, indicating the influence of the southwest monsoon on the territory.

Backward Trajectory of Air Mass reaching Hong Kong in August 2012

For Daily or Seasonal Backward Trajectory Maps, please visit the following webpages:

Daily Backward Trajectory Map
http://www.weather.gov.hk/en/wxinfo/trajectory/trajectory.shtml

Seasonal Backward Trajectory Map
http://www.weather.gov.hk/en/wxinfo/trajectory/trajectorySeasonal.shtml