Tropical Cyclone Track and Position

Notes

• Tropical cyclones centred within the area bounded by 7-36N and 100-140E will be shown on this website. According to the analysed position of the tropical cyclone and the tropical cyclone warning signal in force, the update time of this webpage will be different. Details are listed in the table below:

  	Tropical Cyclone Warning Signal No.1 or above in force	No Tropical Cyclone Warning Signal in force
  		Tropical cyclones centred within the area bounded by 10N and 30N, 105E and 125E.*	Other tropical cyclones centred within the area bounded by 7N and 36N,100E and 140E.
  Update time [Observation time] (Hong Kong time)	Every hour [Every hour]	00:30 [23:00]   03:30 [02:00]   06:30 [05:00]   09:30 [08:00]   12:30 [11:00]   15:30 [14:00]   18:30 [17:00]   21:30 [20:00]	04:00 [02:00] 10:00 [08:00] 16:00 [14:00] 22:00 [20:00]

  *The tropical cyclone track, analysed positions and maximum sustained wind near centre are based on Hong Kong Observatory's tropical cyclone warning for shipping.
  

• While the forecast positions and track indicate the most likely future path of the tropical cyclone, they may deviate from the actual path of the storm. The yellow shaded area on the map indicates the probable area within which the tropical cyclone will fall with a probability of 70% ('Potential Track Area'). Literally, it means that among 10 times of track forecast for similar situations, the tropical cyclone will be centred within the indicated area in about 7 times. The area grows as the forecast hour increases. It will be particularly larger beyond 72 hours and is indicated with lighter shadings on the map. The size in terms of radius of the 'Potential Track Area' corresponding to different forecast hours are determined from the error statistics of the forecasts issued in past years (updated in 2022) and are as shown in the following table:

  Tropical Cyclone Track	Radius of 'Potential Track Area'
  Analysed Position*	15 km
  24-hour forecast position	100 km
  48-hour forecast position	170 km
  72-hour forecast position	255 km
  96-hour forecast position	345 km
  120-hour forecast position	465 km

  *Analysed position refers to the positions of tropical cyclones fixed by the Observatory based on observation data available in real time. Such real-time positions could deviate from those obtained later through 'Best Track Analysis' when more comprehensive sets of observations become available. The corresponding radius of 'Potential Track Area' is determined from the statistics in the past years as the mean value.

• In order to show the forecast track and intensity category of the tropical cyclone clearly, the track maps on this webpage may only display the time labels of some positions of the tropical cyclone. Users can visit the Geographical Information System (GIS) version of the webpage to display all the time labels on an interactive map.
• Short-term erratic departures of the tropical cyclone from the general direction of movement may occur from time to time. These departures are partly due to uncertainties in locating the centre of the tropical cyclone, and partly due to actual short-term variations in the direction and speed of movement of the tropical cyclone itself.