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Forecast Model Announcement

DMI's operational models are run on DMI's super computer. In Q2 2024, DMI will migrate its forecast models to a new super computer. On this page, you can read more about the migration and new versions of models, which will be released when migrating.

We will continuously update this page with more information.

New Version of Weather Model HARMONIE

We are excited to inform you, that a new version of our weather model HARMONIE has been released on our open data portal March 20th 2024. The model is described here.

Transition Period for HARMONIE

The technical documentation for the new version is available and there will be a transition period, where both old and new versions will run in parallel and both be available.

To help you through the transition also a migration guide is available.

End of life HARMONIE NEA og IGB

HARMONIE IGB will have end of life May 13th 2024.

HARMONIE NEA will have end of life May 27th 2024.

What Does This Entail for You as a User?

The new version of HARMONIE has improved horizontal and vertical resolution. Our verification shows that the new version scores better on a variety of parameters such as precipitation, wind, and wind gusts.

There are, however, a number of changes, which will occur, when we change to the new HARMONIE versions.

Our HARMONIE models will change names with the new versions. In the table below, the name changes are shown:

The new HARMONIE versions will also differ from the old versions in the following ways:

Change	Explanation
Data format	The data format will change from GRIB1 to GRIB2. \n \nHARMONIE files in the Forecast Data STAC-API will be in GRIB2 format with new identifies for each parameter. \n \nIf you use the EDR service, then this change will not affect you. However, check with the parameter lists for the new parameter names.

Projection	The Projection will change from rotated lat/lon to a Lambert projection. \n \nTherefore, the grid points in forecast data services will change.

Grid resolution increases (horizontal resolution)	The grid resolution of the model will be increased from 2.5 km to 2 km. \n \nTherefore, the grid points in forecast data services will change, as the resolution is increased.

More vertical levels (vertical resolution)	 The amount of vertical levels in the model will be increased from 65 to 90 levels. \n \nIf you use vertical levels, you will therefore most like have to use a different level with the new version, as the levels will be in different heights than in the previous version.

In addition to the above-mentioned changes, HARMONIE DINI covers a different area, than our HARMONIE NEA covered. The areas that HARMONIE NEA covers and DINI covers can be seen in the pictures below.

Wave Model (WAM) and Storm Surge Model (DKSS)

The new HARMONIE model is a part of DMI’s migration to a new super computer. Our wave model (WAM) and storm surge model (DKSS) will also be migrated to the new super computer in the coming months. There will, however, not be made any changes to our WAM and DKSS in the migration, and migration is planned to go seamlessly, so you should not notice any downtime or changes.