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The NORA3 atmospheric hindcast (NORA3_atmosphere) (Haakenstad et al., 2021; Haakenstad and ) is produced by running the non-hydrostatic HARMONIE-AROME model (Seity et al.,2011, Bengtsson et al.,2017, Muller et al.,2017) with 3km horizontal resolution and 65 vertical levels. The model runs 9 hourly forecasts four times a day. Each forecast starts from an assimilated state of the last forecast adapted to surface observations. Model levels are forced with ERA-5 (

The NORA3 wave hindcast (NORA3_wave) (Breivik et al., 2022) is produced by running the wave model WAM cycle 4.7.0 (Günther et al., 1992; Hasselmann et al., 1988; Komen et al., 1994) with wind forcing from NORA_atmosphere (HARMONIE-AROME Cy40h1.2 hindcast with 3km horizontal resolution), daily ice concentration fields from the ARC-MFC physical reanalysis system of the Copernicus Marine Service (CMEMS) and wave spectra from ERA-5 ( at the boundaries. The WAM model was set up with 30 frequencies logarithmically spanning the range 0.0345–0.5476 Hz and 24 directional bins. 

Data availability


    • Mean sea level pressure
    • Air temperature 2m
    • Relative humidity 2m
    • cloud_area_fraction for high, medium and low cloud types
    • fog
    • lifting condensation level
    • wind speed and direction, 10m
    • surface net longwave radiation and surface net shortwave radiation
    • precipitation amount hourly
    • wind speed and direction in 10, 20, 50, 100, 250, 500, 750m height every hour
    • Air temperature in 50, 100, 150, 200, 300 m height every 3 hours
    • Relative humidity in 50, 100, 150, 200, 300 m height every 3 hours
    • Wind speed and direction in 50, 100, 150, 200, 300 m height every 3 hours
    • Sea surface temperature every 3 hours (updated every 6 hours)


    • Geographical subset of all wave parameters in monthly files
    • Permuted files for fast access to time series in single geographic locations



Bengtsson, L., Andrae, U., Aspelien, T., Batrak, Y., Calvo, J., de Rooy, W., et al. (2017). The HARMONIE–AROME model configuration in the ALADIN–HIRLAM NWP system. Monthly Weather Review, 145(5), 1919–1935.

Breivik, Ø., Carrasco, A., Haakenstad, H., Aarnes, O. J., Behrens, A., Bidlot, J.-R., Björkqvist, J.-V., Bohlinger, P., Furevik, B. R., Staneva, J., and Reistad, M.(2022). The impact of a reduced high-wind Charnock parameter on wave growth with application to the North Sea, the Norwegian Sea, and the Arctic Ocean. Journal of Geophysical Research: Oceans, 127, e2021JC018196.

Günther, H., Hasselmann, S., & Janssen, P. A. E. M. (1992). Wamodel Cycle 4 (revised version) (tech. Rep. No. 4). Deutsches KlimaRechenZentrum.

Haakenstad, H., Breivik, Ø., Furevik, B., Reistad, M., Bohlinger, P., & Aarnes, O. J. (2021). NORA3: A nonhydrostatic high-resolution hindcast of the North Sea, the Norwegian Sea, and the Barents Sea. Journal of Applied Meteorology and Climatology.

Haakenstad, H., & Breivik, Ø. (2022). NORA3. Part II: Precipitation and Temperature Statistics in Complex Terrain Modeled with a Nonhydrostatic Model, Journal of Applied Meteorology and Climatology61(10), 1549-1572.  DOI:

Hasselmann, S., Hasselmann, K., Bauer, E., Janssen, P. A. E. M., Komen, G. J., Bertotti, L., et al. (1988). The WAM model—A third generation ocean wave prediction model. Journal of Physical Oceanography, 18, 1775–1810.

Komen, G. J., Cavaleri, L., Donelan, M., Hasselmann, K., Hasselmann, S., & Janssen, P. A. E. M. (1994). Dynamics and modelling of ocean waves. Cambridge University Press.

Müller, M., Y. Batrak, J. Kristiansen, M. A. Ø. Køltzow, and G. Noer, 2017a: Characteristics of a convective-scale weather forecasting system for the European Arctic. Mon. Wea. Rev., 145, 4771–4787, 

Müller, M., and Coauthors, 2017b: AROME-MetCoOp: A Nordic convective-scale operational weather prediction model. Wea. Forecasting, 32, 609–627,

Seity, Y., Brousseau, P., Malardel, S., Hello, G., Bénard, P., Bouttier, F., et al. (2011). The AROME-France convective-scale operational model. Monthly Weather Review, 139(3), 976–991.