850hPa (Approx. Altitude:1500m) - Wind Speed & Wind Direction
easterly wind of 18 km/h (one barb represents wind speed of 18 km per hour and a half-barb represents 9 km per hour)
westerly wind of 90 km/h (a pennant, or triangular flag, represents wind speed of 90 km per hour)
strong winds (41-62 km/h) and above are plotted in red
These prognostic charts start updating at 03 HKT, 09 HKT, 15 HKT, 21 HKT everyday.
The computer forecast weather maps are generated by the Observatory's
computer model directly without manual adjustment and the forecast
weather conditions described in the products may be different from
that in the weather forecasts issued by the Observatory. For a full
assessment of the weather situation, the public should refer to the
forecasts issued by the Observatory and/or the respective
local meteorological authorities.
Please refer to the following forecasts/bulletins by relevant
meteorological authorities -