Tl;dr: Four new weather models are available at Open-Meteo:

Global, North-American and Canadian GEM models from the Canadian Weather Service
The MET Nordic model from the Norwegian Meteorological Institute

Models are already integrated into the seamless weather prediction API selecting the best weather models automatically for every location worldwide. Two new dedicated APIs for GEM and MET Norway offer more detailed information for each model.

Global Environmental Multiscale Model (GEM)

The Canadian Meteorological Center (CMC) offers forecasts from their GEM weather models as open data. Data assimilation and model initialisation is independent from other national weather services. Therefore, GEM is a great addition to Open-Meteo to compare multiple weather models with each other.

GEM calculates one global weather model at 15 kilometre resolution every 12 hours and multiple regional weather models every 6 hours. Regional weather models are “nested” into the global domain and refine weather forecasts with 2.5 kilometre high resolution.

At Open-Meteo, 3 GEM models are now available:

GEM Global, 15 km resolution, 10 days forecast
GEM RDPS Regional (entire North America up to the North Pole), 10 km resolution, 3.5 days forecast
GEM HRDPS (most of Canada, northern U.S.), 2.5 resolution, 2 days forecast

Both regional GEM models use a polar stereographic projection. Because of this projection, the “GEM Regional 10 km“ model covers North America, but also parts of Russia, Island and Greenland. On the map below, you can see the full extend of this domain.

GEM RDPS Regional model, 10 km resolution

The high-resolution GEM HRDPS model covers most of Canada and the Northern US. Although, this domain looks smaller, due to the 2.5 kilometre resolution, it contains almost 5 times more data! In total, roughly 200 GB of data are downloaded every day from the CMC open-data server (Detailed numbers will follow in another blog post).

For many locations in Canada and Northern U.S., 8 weather models can be used. Below is a temperature forecast for Ottawa for the next 7 days. Currently (red-line) all weather models show the same temperature, but diverge by up to 5°C for the next days.

To quickly compare all weather forecasts, you can use the Open-Meteo Weather Forecast API and manually select all available weather models. Don’t worry if you select too many, they will just now show up in the graph.

All 3 new GEM weather models offer a large variety of weather variables on surface and up to 31 atmospheric pressure levels. To show in maximum detail which weather information is available for GEM, a dedicated GEM API is available here. There you will also find a table with all models and additional links.

MET Nordic

MET Nordic is a post-processed weather model from the Norwegian Meteorological Institute. It is based on an 2 kilometre model, but downscaled to 1 kilometre resolution with current measurements, radar observations and nowcasting.

The model updates every hour and should cover current weather conditions and next hours quite well.

Although, this model optimises short-term local forecasts, up to 2.5 days of data are available as well. MET Nordic is nested into ECMWF IFS and should maintain a good forecast still the entire 2.5 days.

The map below illustrates the covered area for MET Nordic: Norway, Denmark, Sweden, Finland and parts of the Baltic countries.

Similar to GEM, MET Nordic is integrated into the Open-Meteo Seamless prediction system and will be automatically used to improve the weather forecast in those regions.

A dedicated MET Norway API has more detailed information about the available weather variables.

What’s next?

GEM and MET Nordic weather models have been requested by Open-Meteo users. If you would like to get another weather model integrated please get in touch!

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New weather models: Canadian GEM and MET…