Tropical Cyclone Position
The analyzed tropical cyclone positions on this map are based on Hong Kong Observatory's tropical cyclone warning for shipping issued about two hours after the time of observation. They incorporate additional information derived from surface and upper-air data and may therefore be slightly different from the real-time satellite or radar-based positions given in the hourly bulletins for public.
Accuracy in the analyzed positions is usually within 30 kilometres. Average errors in the 24 and 48-hour forecast positions are of the order of 175 and 330 kilometres respectively.
There can be short term erratic departures from the general direction of movement. These departures are partly due to difficulties in locating the centre of the tropical cyclone, and partly due to short term fluctuations in the direction and speed of movement of the centre.
