In Q2 2024, DMI will migrate its forecast models to a new super computer and upgrade our weather model HARMONIE. This will introduce some breaking changes, read the full announcement here.
DMI forecast data consist of various models obtainable through a set of APIs. Each model contains different parameters relating to a specific domains like ocean (WAM), storm flooding (DKSS) or weather (HARMONIE). The APIs allow you to fetch the data in different ways, depending on your needs.
A single forecast calculated at a certain point in time is referred to as a model run and contains a given number of time steps.
Each model targets a specific domain, contains a unique set of parameters, and is calculated for a set of areas of interest to DMI.
The following models are available:
| Model name | Model areas | Description | Example parameters |
|---|---|---|---|
| HARMONIE (DINI and IG) | Link | Weather model, contains land and sky parameters. DMI uses this model for forecasting to media, air traffic, etc. | Land Temperature, Wind in several heights, Sun Radiation, Pressure, Humidity, Cloud Cover and much more. |
| WAM | Link | Wave model. DMI uses this model for shipping forecasts. It is used together with flooding forecasts to predict maximum water height. | Wave Height, Wave Period, Ocean Wind |
| DKSS | Link | Storm Surge model. DMI uses this model to predict and warn about flooding and water levels. | Water Level, Ocean Current |
When is data normally available
DMI offers forecasts in 2 different APIs, following 2 different API standards:
Each has its own advantages. Please see more below.
An API that has the latest 48 hours of forecast model runs available as files in GRIB format.
This API is useful when you need the full model or a large portion of it, since the GRIB format is compact and faster to download compared to EDR.
EDR support a limited set of query options (time, area and parameter), so more advanced filtering would require downloading the data through this API and performing it yourself.
Compared to EDR (which returns JSON), the GRIB format requires specialized tooling to parse: link to official tooling. Helpful examples on working with GRIB can be found in our examples page. Even so, for most people JSON is much easier to work with, in which case EDR might suit your needs better.
An API that has the latest 24 hours of forecast model runs available in JSON (as either GeoJSON or CoverageJSON).
This API is useful when you need a small part of the model. The EDR API supports the following filtering options:
The EDR API is well suited for small queries (a few thousand data points) per request, so for large data amounts the STAC API should be used.
Either look at the EDR API documentation or STAC API documentation to see how to query the API.
Then inform yourself on the model you wish to work with, and look at parameter lists to see which parameters are useful to you. The Forecast Data STAC-API and the Forecast Data EDR API both contain the same forecast models so the data is the same. Because the Forecast Data EDR API allows picking specific parameters from the forecast, the naming of these are specific to the Forecast Data EDR API.
| Model | STAC-API parameter list | EDR API parameter list |
|---|---|---|
| Weather Model (HARMONIE) | HARMONIE Parameters | HARMONIE Parameters |
| Wave Model (WAM) | WAM Parameters | WAM Parameters |
| Storm Surge Model (DKSS) | DKSS Parameters | DKSS Parameters |