Daily Backward Trajectory Map

Past Backward Trajectory Map

Past 72-hour Backward Trajectory of Air Mass
reaching Hong Kong at 8 a.m.

Data not available

• Monthly Backward Trajectory Map
• Seasonal Backward Trajectory Map
• Forecast Air Trajectory

Points to note:

• The above diagram shows the past 72-hour backward trajectory of air mass reaching Hong Kong at a height of 100 metres above ground level ending at 8 a.m.
• The product may be useful for tracing the origin of air mass reaching Hong Kong.  Please click here for cases of the backward trajectory map under different weather patterns.
• Normally, this web page will be updated daily at around 5 p.m.
• Archive of trajectories is available for the past 30 days.
• The trajectory was prepared using the HYSPLIT model of NOAA and output from numerical weather prediction models.

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