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OpenIFS is based on ECMWF's IFS (Integrated Forecast System) code. The first version of OpenIFS is based on Cycle 38R1, the operational model introduced in June 2012 (it has since been superceded for operations from June 2013).
IFS CY38R1 comprises approximately 1.3 million lines and 5200 files. OpenIFS comprises roughly 0.5 million lines in 2600 files. OpenIFS is designed to be easy to install on external computer systems.
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