Background: Numerical weather models at the heart of forecasting work
Numerical weather prediction models are the backbone of modern meteorology. They process meteorological measurement data collected worldwide from ground stations, radiosondes, aircraft, ships, weather radars and satellites. Using physical equations, this data is converted into forecasts that provide information on temperature, wind, precipitation, air pressure and many other parameters.
The new ICON-D2-RUC model is based on the proven ICON model family, but is specially designed for very short-term forecasts (up to 14 hours in advance). While the previous ICON-D2 model is started every three hours and has a runtime of 48 hours, ICON-D2-RUC supplements this with hourly updates with a clear focus on fast-moving weather situations.
Innovation: Hourly updates and fast availability
A central feature of the ICON-D2-RUC is its Hourly update. This means that a new forecast is calculated every full hour, which is already around 40 minutes after model start is available. This allows the DWD to react to new observations almost in real time and assess weather developments much more precisely - a decisive advantage, especially in aviation, where every minute counts.
This frequency of model runs is also remarkable internationally: only a few weather services worldwide currently operate a high-resolution model in rapid update mode.
Focus: High-precision thunderstorm and severe weather forecasts
The model is particularly relevant for forecasting convective weather situations - i.e. Thunderstorm cells, Squall lines, Hail events and Flash floods. Especially with so-called Supercells or mesoscale convective systemswhich can form within a few hours and cause massive damage, ICON-D2-RUC promises significantly improved forecasts.
By using more complex cloud and precipitation models, the model can depict the vertical structure of the atmosphere in detail. With a horizontal resolution of around 2 km ICON-D2-RUC offers the necessary finesse to realistically depict small-scale phenomena - such as the occurrence of local tornadoes or heavy rainfall events at the community level.
Special technical feature: forecasting artificial radar signals
Another special feature: ICON-D2-RUC also generates simulated Radar signals - In other words, a kind of virtual radar image that shows how a real radar would record the weather situation based on the model atmosphere. This data can be compared with classic Radar nowcasting products This is particularly important for continuous, automated weather films and early warning systems.
The result is a hybrid product of observation and model forecasting that is likely to set new standards in the quality of weather visualisation - both for meteorologists and for users such as air traffic controllers, pilots or civil protection forces.
Significance for general aviation
For pilots of the general aviation - from glider pilots to private motorised aircraft - precise, short-term weather information is essential. ICON-D2-RUC allows significantly improved assessments of local hazards such as:
- Suddenly developing thunderstorm cells along flight paths
- Wind gusts near the ground during take-off and landing
- Rapidly approaching heavy rain that jeopardises visual flight conditions
In conjunction with mobile weather apps, online briefing portals and flight planning systems, ICON-D2-RUC can enable even more timely and specific warnings for pilots in future - for example in the form of dynamic weather layers on moving maps.
Outlook and international categorisation
With ICON-D2-RUC, the German Weather Service is sending a strong signal in the direction of high-frequency, model-based weather warning systems. The model is also being integrated into international systems as part of European co-operation (e.g. EUMETNET, EUMETSAT) and is therefore likely to serve as a model for comparable developments at other weather services.
A possible next step: the integration of artificial intelligence for the automated interpretation of model outputs and the creation of customised warnings for specific user groups - a field in which the DWD is already involved in research.
ConclusionThe new ICON-D2-RUC model represents a significant advance in short-term weather forecasting - especially for safety-critical applications such as general aviation. It combines up-to-the-minute observations with state-of-the-art modelling and will therefore help to identify dangerous weather situations faster and more precisely in the future. Team and with the necessary respect for technology.
Source references:
DWD