Numerical weather prediction

Research on numerical weather prediction is performed at FMI mainly within the HIRLAM (High Resolution Limited Area Model) consortium. HIRLAM is an international program aiming to develop synoptic and mesoscale weather prediction models, the stress at present being on the latter. In addition to the Finnish Meteorological Institute, program participants include corresponding institutes from Sweden, Norway, Denmark, Iceland, the Netherlands, Ireland, Spain, Estonia and Lithuania. There is also close co-operation with France.

The development of HIRLAM was started in 1985, and has since been going in several phases. The first version of the model was completed in 1989 and introduced into operational use at FMI in 1990. Presently, model version 7 is in use.

In addition to developing the model, the program participants use it operationally in weather forecasting. Since 2003, FMI has  had a special status in HIRLAM, acting as the so called Lead Centre for the RCR (Regular Cycle with the Reference), which includes the special duty of running the official reference version of the HIRLAM model as its operational weather forecast model. The results and experiences thus gained are then utilized in model development. Internationally, HIRLAM has been found comparable to the models developed in larger countries such as the United Kingdom, France, and Germany.

The current horizontal resolution of the HIRLAM RCR model is 7.5 km. At present, the current operational setup produces daily four 54 hour regional forecasts for extended European area (Figure below).

Starting from 2006, an extensive co-operation between HIRLAM and the French-led ALADIN model consortia has been going on. As a result, an urban scale meso model HARMONIE with horizontal resolution of 2.5 km has been developed and is now also in operative use at FMI. Starting from 2011, the emphasis in model development in the HIRLAM progran has been shifted to this new HARMONIE system.

Intergration areas of the two FMI's limited area weather forecast models (outer HIRLAM, inner HARMONIE).