NORA3. Part II: Precipitation and Temperature Statistics in Complex Terrain Modeled with a Nonhydrostatic Model

Abstract

The 3-km Norwegian Reanalysis (NORA3) is a convection-permitting, nonhydrostatic hindcast for the North Sea, the Norwegian Sea, and the Barents Sea as well as the Scandinavian Peninsula. It has a horizontal resolution of 3 km and provides a full three-dimensional atmospheric state for the period 1995–2020 with a surface analysis and boundary conditions from ERA5, a global reanalysis. In complex terrain it is found to outperform both the host reanalysis ERA5 and also the earlier hydrostatic 10-km Norwegian Hindcast Archive (NORA10), in terms of 2-m temperature and daily precipitation. Of particular interest is the representation of extreme rainfall. It is found that the upper percentiles are much better represented than in ERA5, with very little bias up to 99.9%, suggesting that the new hindcast archive is well suited for hydrological mapping and extreme-value analysis of rainfall in complex terrain.