WAFS Gridded Forecasts of Icing, Turbulence and Cumulonimbus Clouds

The World Area Forecast Centres London and Washington are now providing gridded forecasts of icing, turbulence and cumulonimbus clouds on a trial basis for users' evaluation. To facilitate the evaluation, a new webpage on WAFS Gridded Forecasts of Icing, Turbulence and Cumulonimbus Clouds (CB) is available on the AMIDS. The 6-hour and 24-hour forecasts for the following five sets of gridded forecasts are provided for the global and Asian regions:

• maximum icing potential for the layer centred at FL180
• mean in-cloud turbulence for the layer centred at FL180
• maximum Clear Air Turbulence for the layer centred at FL340
• CB horizontal extent
• ICAO height at CB top

The corresponding satellite pictures and significant weather forecast charts, if available, are also provided alongside with these gridded forecasts for easy comparison.

Users are encouraged to send feedback on these trial products via email (amids@hko.gov.hk). A survey will be conducted to collect user's feedback systematically in due course.

Fig.1: AMIDS webpage providing the WAFS Gridded Forecasts of Icing, Turbulence and Cumulonimbus Clouds for evaluation by aviation users.