Backward Trajectory Map in July 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 July 2012 is now available on the following webpage:

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

In July 2012, the air masses reaching Hong Kong mostly originated from the south and southwest, indicating that the territory was mainly under the influence of the southwest monsoon.

Backward Trajectory of Air Mass reaching Hong Kong in July 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