KNMI projects Water levels HARMONIE-AROME

Meteorological forcing



HARMONIE-AROME for North Sea Forecasts


The new standard model for regional weather forecasting is HARMONIE-AROME. The intent is to replace the use of Hirlam data in all applications by HARMONIE-AROME. Rijkswaterstaat (RWS) has several maritime applications that use Hirlam data, e.g. for storm surge forecasting on the North Sea up to 48 hours ahead.

Model domain

The domain of the HARMONIE-AROME model as used by KNMI is not large enough for even the previous version of the storm surge model (DCSMv5). Therefore, HARMONIE-AROME data have to be extended to cover the complete domain of the storm surge model.
To extend the HARMONIE-AROME domain, data of the model that supplies the lateral boundary conditions for HARMONIE-AROME itself can be used. HARMONIE-AROME (as of version 38) takes its boudary conditions directly from the ECMWF IFS model, which are readily available from the ECMWF MARS archive.


For the validation of HARMONIE-AROME input for RWS applications, reforecasts have been produced for a number of storm surge cases in the past and also for the complete years 2015, 2016 and 2017, and, separately, the winter season September 2017 – March 2018. We used these at KNMI to generate storm surge forecasts with the WAQUA/DCSMv6 model. As a comparison, also ECMWF input has been used.
Hans de Vries, © KNMI, April 23, 2019