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where 𝛼 is the local rotation of the model grid relative to North, and atan2 is the very specific 2-argument arcus tangens function, which is included in most programming languages. For definition of the atan2 function, see for instance at https://en.wikipedia.org/wiki/Atan2. Take care to check if the atan2 result is in radians, in which case it should be converted to degrees with the factor 180°/π. Also take care to check if the resulting direction is between 0° and 360°. Note that the wind direction is the direction from which the wind comes! The grid rotation angle 𝛼 can be computed with this script: https://github.com/metno/NWPdocs/wiki/Examples/#wind-direction-obtained-from-x-y-wind.
10-metre u and v wind gust components are also output. These are computed from the diagnosed 10-metre winds and the turbulent kinetic energy (pers. comm. Gwenaëlle Hello, Meteo France, 2007).
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