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

According to the backward trajectory map below, the air masses reaching Hong Kong in the first half of May 2012 mostly originated from the south. With the prevalence of warm southerly airstreams and abundant sunshine, the mean temperature of Hong Kong rose to 27.7 degrees during 1 to 15 May and tied with that of 1977 as the highest in the first half of May since record began. On the other hand, the air masses reaching Hong Kong in the second half of the month mainly originated from the east or northeast, indicating the influence of easterly airstreams over the territory.

Backward Trajectory of Air Mass reaching Hong Kong in May 2012


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

Daily Backward Trajectory Map

Seasonal Backward Trajectory Map


Last revision date: <20 Dec 2012>