More weather information on web from the Observatory's new computer model
27 September 2010
The Hong Kong Observatory announced today (September 27) the enhancement in two types of weather services, the Computer Forecast Weather Map and the Wind Forecast for Water Sport Activities, on its website.
The Computer Forecast Weather Map (www.hko.gov.hk/nhm/nhme.htm) provides computer-generated prediction of the evolution of weather patterns over East Asia and the western North Pacific. The update frequency of the predictions has been increased from twice per day to four times per day. The products include weather, temperature, mean sea level pressure, relative humidity and winds. The newly introduced relative humidity information at ground level is particularly useful in the cool seasons when under the influence of a dry continental air mass. Hill fires in the countryside can bring extensive and sometimes life-threatening damage. Figure 1 is an example of a 24-hour forecast of relative humidity and air flow generated by the new computer model, showing dry continental air reaching south China.
The Observatory's webpage Wind Forecast for Wind Surfers has been enhanced and renamed as Wind Forecast for Water Sport Activities (http://www.hko.gov.hk/sports/wind.htm). (Figure 2 shows an enhanced forecast for the water sports community.) The forecast period is lengthened from one to three days so that users can plan further ahead their wind-sensitive water sport activities. In addition to the daily update before daybreak, another update before noon has also been introduced to provide the latest assessment of the daytime weather.
These enhancements are made possible through the operation of a new generation of numerical weather prediction models at the Observatory. The highest resolution of weather models previously run by the Observatory was 20km. The new suite of models offers a resolution down to 2km, providing more details on weather systems affecting the territory. Making use of the high-resolution digital outputs of the models, more location-specific weather information can now be provided.
The high-resolution model suite is powered by a computer system installed at the Observatory earlier this year. The system is some 400 times faster than the old system acquired in 1999.
Figure 1 24-hour forecast of relative humidity and air flow generated by the new computer model, showing dry continental air reaching south China.
Figure 2 Enhanced forecast products for the water sport community.