New 21-day forecast on Beta-Yr

The Norwegian Meteorological Institute has together with Climate Futures and NRK developed a 21-day weather forecast. The service is now being tested at During the test phase the developers want to collect experiences and feedback from users, so that the forecast can be furter developed and published on the regular yr site this autumn.

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The first 10 days of the 21-day forecast correspond to the first 10 days of the normal weather forecast now seen at Yr. From day 11 until day 21, datasets for weekly values ​​from the meteorological center in Reading, ECMWF. From day 10 to day 14 the forecast is updated twice a day, and from day 15 to 21 it is updated once per day. Behind the data lies a lot of probability calculation and ensemble forecasts, and up to 100 possible weather forecasts are included in this long-term data.

The forecast will naturally be most precise early in the period, but for industries that need to see trends and tendencies further into the future, this can provide an indication of future weather development. In this article at Yr, you can read more about how the forecast is being developed and how you can give feedback to the developers.