The computational system
As an example of a computational weather forecasting system, the figure below shows the setup built around the HIRLAM limited area model used at the Finnish Meteorological Institute (FMI). HIRLAM has been developed and is used within the international HIRLAM consortium.
To start with, observations from various sources are collected and transmitted to the system. In addition to international networks, Baltic Sea surface temperature and ice data are obtained from the marine branch of the FMI. Vice versa, wind speed and other meteorological data are transmitted to the marine branch to be used in their wave and sea surface level models.
The atmospheric evolution at the boundaries of the HIRLAM area is obtained from the European Centre for Medium Range Forecasts (ECMWF). Forecast results are also archived there for the use of the whole HIRLAM consortium. Local archiving for in-house products and for meteorologists' work stations also takes place. Finally, graphical visualisation products and monitoring information of the forecast is stored on a web server for viewing.
Computations take place on the FMI's Cray XC30 supercomputer. The computer setup includes two identical units, one of which is used in production, the other one acting as backup. During normal operations, the backup unit is available for research purposes. Both units consist of 3420 computational units with a peak power of 70 TFlops.