HARMONIE for superior short-range forecasts in the Netherlands

  • This has been mentioned in other posts (e.g. here), but for the Netherlands HARMONIE 2.5km is the best short-range prediction model by a long shot. It is for example the only model that accurately predicts sea breeze, which is very relevant in this coastal country. HARMONIE-40 is the operational short-range model for the Dutch Meteorological Institute (KNMI). Note that ECMWF is decent and also used by the KNMI but only for medium-range forecasts.

    I read somewhere else on this forum that 'more models will only confuse', but for the Netherlands HARMONIE 2.5km and ECMWF are really the only models you'll need.

    HARMONIE can be downloaded for free from the KNMI datashare, you'll find more information here.

  • Sailor Moderator

    I can’t say how HARMONIE is good, but for sea breeze you can use ICON 7km and AROME 2km (in fact 1.3km exactly). They are good too. Here a day of sea breeze last year with AROME.


  • Thanks @idefix37. I am aware that other models predict sea breeze, but for the Dutch coast they are not accurate enough. Apart from accurately predicting sea breeze HARMONIE in general is really the go-to short-range model for the Netherlands.

    EDIT: to elaborate a bit, HARMONIE is specifically tailored to the Netherlands by the (only) meteorological institute and it really shows. As said it is the official operational short-range model and there's no discussion here that other models are in a different ballpark, especially for wind predictions.
    EDIT2: just historically it's nice to know that HARMONIE is based on AROME... :)

  • And one other addition: there are quite a lot of countries whose short-range forecasts are based on HARMONIE: "... Denmark, Estonia, Finland, Iceland, Ireland, Lithuania, the Netherlands, Norway, Spain, and Sweden." (Bengtsson et al., 2017).

    The challenge will be to get those predictions from their respective national institutes. At least for the Netherlands they are freely available (see link in my first post).

    I think it would be worth the effort to include HARMONIE-40 2.5km in Windy, if it works out for the Netherlands maybe those other countries might follow relatively easily.

  • While looking at the forecast for tomorrow there's a big difference in prediction.
    Ardome vs Harmonie Jun 12 at 12h00 around Markermeer.

    Arome Jun 19 12h00.png

    Harmonie Jun 19 12h00.png

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