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Backward Trajectory Map in July 2011

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 2011 is now available on the following webpage:

In July 2011, most of the air masses reaching Hong Kong originated from the South China Sea. With a trough of low pressure lingering along the coast of southern China, air masses came to Hong Kong from the southwest in the third week of the month. Under the influence of tropical cyclone Nock-ten, air masses from the western North Pacific reached Hong Kong on 27th and 28th.

Backward Trajectory of Air Mass reaching Hong Kong in July 2011


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

Daily Backward Trajectory Map

Seasonal Backward Trajectory Map


Last revision date: <21 Dec 2012>