Aviation applications of a new generation of mesoscale numerical weather prediction system of the Hong Kong Observatory

In 2010, the operational numerical weather prediction (NWP) model suite at the Hong Kong Observatory (HKO) has been upgraded to the Non-Hydrostatic Model (NHM) with horizontal resolution of 10 km and 2 km. The NHM, adapted from Japan Meteorological Agency (JMA), replaced the previous NWP system using Operational Regional Spectral Model (ORSM) with the finest resolution of 20 km. With the increase of spatial resolution, use of 3-dimensional variational data assimilation system and more advanced model physics, NHM is found to capture better the mesoscale weather phenomena over southern China and the South China Sea. This paper discusses two aviation applications of NHM, namely the upper-air winds forecasts for aircraft flight levels, and the turbulence intensity guidance for preparation of significant weather charts. NHM is found to outperform ORSM in the forecasting of upper-air winds as verified against aircraft data, and basically on par with the performance of the global model. The turbulence intensity guidance demonstrates promising skills in capturing the occurrence of moderate turbulence as verified using eddy dissipation rate (EDR) calculated from the wind data of commercial jets. The performance is similar to the turbulence products from the World Area Forecast Centres based on global NWP models. Further studies in other aviation applications of NHM would also be discussed.