Windy Community
    • Unread
    • Categories
    • Groups
    • Go to windy.com
    • Register
    • Login

    Why same model (ECMWF) differ in other sites/apps

    Scheduled Pinned Locked Moved General Discussion
    19 Posts 4 Posters 13.5k Views 2 Watching
    Loading More Posts
    • Oldest to Newest
    • Newest to Oldest
    • Most Votes
    Reply
    • Reply as topic
    Log in to reply
    This topic has been deleted. Only users with topic management privileges can see it.
    • Filip_KF Offline
      Filip_K Windy Staff @Dimitar Mihaylov
      last edited by Filip_K

      Hi @Dimitar-Mihaylov, according to this article, windy.app uses some other model from ECWMF (14km resolution, updated twice a day). ECMWF-HRES model on windy.com has 9km resolution and is updated 4 times a day.

      1 Reply Last reply Reply Quote 1
      • idefix37I Offline
        idefix37 Sailor Moderator @Dimitar Mihaylov
        last edited by idefix37

        @Dimitar-Mihaylov
        @Filip_K

        In fact for the atmosphere parameters windy.app is probably using the free version of IFS which comes with a 25km resolution. It is called “WMO essentials”.
        But for sea parameters they use the 14km resolution model.
        At ECMWF there is no 14km resolution model for the atmosphere parameters as you can see :
        https://confluence.ecmwf.int/plugins/servlet/mobile?contentId=324860211#content/view/324860211
        They deceive the users using the 14 km resolution as the general resolution of the ECMWF forecast they show.

        1 Reply Last reply Reply Quote 1
        • idefix37I Offline
          idefix37 Sailor Moderator @Dimitar Mihaylov
          last edited by idefix37

          @Dimitar-Mihaylov

          At the altitude of your ski resort, 25km resolution vs 9km resolution that makes a big difference. In addition model updates can be different.
          Check the run time of the models, called the Reference time in Windy.

          98FBF2E1-DB55-41E9-A99C-0C5AFBA5BE84.jpeg

          1 Reply Last reply Reply Quote 0
          • Dimitar MihaylovD Offline
            Dimitar Mihaylov | Premium
            last edited by

            Well, okay, so we can assume the windy.com forecast should be more accurate.

            Would've been great if I could stay at a mountain hut and just make a prospective trail comparing the two forecasts :)

            Anyhow.

            One more question which is offtopic - as I can see few of you are developers/moderators - do you consider adding a "freezing level" line as in the windy.app interface? That feature I must say is really handy. Thanks.

            Filip_KF 1 Reply Last reply Reply Quote 0
            • Filip_KF Offline
              Filip_K Windy Staff @Dimitar Mihaylov
              last edited by

              Hi @Dimitar-Mihaylov, already available: https://www.windy.com/-Show---add-more-layers/overlays?deg0,48.546,31.399,5

              Dimitar MihaylovD 1 Reply Last reply Reply Quote 0
              • Dimitar MihaylovD Offline
                Dimitar Mihaylov @Filip_K | Premium
                last edited by

                @Filip_K said in Why same model (ECMWF) differ in other sites/apps:

                Hi @Dimitar-Mihaylov, already available: https://www.windy.com/-Show---add-more-layers/overlays?deg0,48.546,31.399,5

                Oh, great.

                Can I add it into the "forecast window" with the wind/temp/snow/rain/etc or I can see it only on the map when I move it around? Because when I choose one of my saved favourite spots the freezing level is not shown.

                Thanks again.

                Filip_KF 1 Reply Last reply Reply Quote 0
                • Filip_KF Offline
                  Filip_K Windy Staff @Dimitar Mihaylov
                  last edited by

                  @Dimitar-Mihaylov
                  I'm afraid only map and airgram display freezing level.

                  In airgram, freezing level is the white line between blue and green mass. And the left axis is in pressure levels which makes it quite difficult to get actual freezing altitude.
                  Screenshot_20240213_154821.png

                  But picker displays such value anywhere:
                  Screenshot_20240213_155155.png

                  1 Reply Last reply Reply Quote 0
                  • Dimitar MihaylovD Offline
                    Dimitar Mihaylov | Premium
                    last edited by

                    Yes, that's what I thought. It's not really useful in that configuration but hopefully it will get added in the forecast grid.

                    idefix37I 1 Reply Last reply Reply Quote 0
                    • idefix37I Offline
                      idefix37 Sailor Moderator @Dimitar Mihaylov
                      last edited by idefix37

                      @Dimitar-Mihaylov
                      What you call the “forecast grid” is probably the Basic meteogram called Basic in Windy. For the freezing level you just need to switch on Airgram, as @Filip_K said.
                      I don’t know if a customisable meteogram could be made. Probably not easy.

                      Dimitar MihaylovD 1 Reply Last reply Reply Quote 0
                      • Dimitar MihaylovD Offline
                        Dimitar Mihaylov @idefix37 | Premium
                        last edited by

                        @idefix37 said in Why same model (ECMWF) differ in other sites/apps:

                        @Dimitar-Mihaylov
                        What you call the “forecast grid” is probably the Basic meteogram called Basic in Windy. For the freezing level you just need to switch on Airgram, as @Filip_K said.
                        I don’t know if a customisable meteogram could be made. Probably not easy.

                        I checked the Airgram but as mentioned before - the reference axis for the freezing level is air pressure not altitude which is not useful, at least not for me.

                        idefix37I 1 Reply Last reply Reply Quote 0
                        • idefix37I Offline
                          idefix37 Sailor Moderator @Dimitar Mihaylov
                          last edited by idefix37

                          @Dimitar-Mihaylov
                          Yes, but you must know that the weather model calculations are all based on air pressure levels, not on real elevation.
                          However it would be useful to display the average elevation corresponding to these pressure levels. As it is displayed just below for clouds but not very detailed:

                          3374CF09-2F4F-4CB1-B00B-50BAFE3E0730.jpeg

                          Or you need to make your own pressure / averaged elevation scale yourself.

                          Dimitar MihaylovD 1 Reply Last reply Reply Quote 0
                          • Dimitar MihaylovD Offline
                            Dimitar Mihaylov @idefix37 | Premium
                            last edited by

                            @idefix37 said in Why same model (ECMWF) differ in other sites/apps:

                            @Dimitar-Mihaylov
                            Yes, but you must know that the weather model calculations are all based on air pressure levels, not on real elevation.
                            However it would be useful to display the average elevation corresponding to these pressure levels. As it is displayed just below for clouds but not very detailed:

                            3374CF09-2F4F-4CB1-B00B-50BAFE3E0730.jpeg

                            Or you need to make your own pressure / averaged elevation scale yourself.

                            I understand and know that most of the calculations are based on the air pressure levels but that doesn't change the fact it's not convenient for the normal user.

                            This is exactly every application's "you had one job" thing - to process the information and present it in a understandable way.

                            If I wanted to do my own calculations with the raw data then I would not use any app at all.

                            Anyway - that was just a suggestion for improving the UI.

                            idefix37I 1 Reply Last reply Reply Quote 0
                            • idefix37I Offline
                              idefix37 Sailor Moderator @Dimitar Mihaylov
                              last edited by

                              @Dimitar-Mihaylov
                              I do not ask you to do your own calculations with the raw data, just to imagine this

                              3C376B26-39B4-4940-8660-89483C9A37EC.jpeg

                              This has been already asked to Windy…

                              1 Reply Last reply Reply Quote 0
                              • First post
                                Last post
                              Windy Community  |  Powered by excellent NodeBB
                              Terms of Use     Privacy Policy     Windy.com