Backward Trajectory Map in September 2012

In September 2012, most of the air masses reaching Hong Kong originated from the north, northeast and east, indicating that the territory was under the influence of the continental airstreams and easterly airstreams.

Backward Trajectory of Air Mass reaching Hong Kong in September 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 September 2012 is now available on the following webpage:

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

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