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    What source of weather data Windy use?

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    • Gkikas LGPZG
      Gkikas LGPZ Moderator @nicolazeni
      last edited by Gkikas LGPZ

      @nicolazeni
      Pressure isolines (isobars) are always from ECMWF.
      I think there is a problem here
      because when in satellite and activate "pressure"
      the isobars are those from the last session.
      @developers
      @Korina
      must try to replicate the following:

      Now, 12 May/23 Local (20 UTC) there is a high pressure ridge over Morocco
      77f359ee-7fa7-4217-b2d8-d6128df6673f-εικόνα.png
      ........

      Gkikas LGPZG 1 Reply Last reply Reply Quote 1
      • Gkikas LGPZG
        Gkikas LGPZ Moderator @Gkikas LGPZ
        last edited by

        ..... I go forward at (let say) Sat 16 May (20 UTC)
        2fd65f9f-7a01-4c53-84e0-3106addeeee6-εικόνα.png
        there is a 1021 hPa High over Morocco......

        Gkikas LGPZG 1 Reply Last reply Reply Quote 1
        • Gkikas LGPZG
          Gkikas LGPZ Moderator @Gkikas LGPZ
          last edited by

          .... now,
          if I go to satellite layer and activate pressure isolines (isobars)
          55c12f34-3800-498f-83a9-5ebafcc898e1-εικόνα.png
          I see those for Sat 16 May !!! with the 1021 hPa High over Morocco
          (although sat. image is for today 12 May).

          idefix37I 1 Reply Last reply Reply Quote 3
          • vsinceacV
            vsinceac | Premium
            last edited by vsinceac

            As said in my previous post above, if forecasts and satellite image layers are displayed together on map, there would be a bug: they cannot be contemporary (excepted at full hours, maybe).

            Satellite images are provided every 10 or 15 minutes; Windy should obtain that worldwide mosaic by merging images from differrent satellites, taken at small time difference (a couple of minutes or so, but surely not hours).

            When combining satellite and atmospheric pressure layers together on map, then playing the animation over the whole available period on timebar (i.e. last 2, 6 or 12 hours), one can see that the pressure layer remains static over the whole period, while satellite images layer change at each time step...

            Thus the pressure isobars layer doesn't follow current value on timebar as expected, which is wrong from my pov.

            Having a static pressure isobars layer combined with animated satellite images would be useful for some specific deep analysis, but in such a case the validity time of the static layer should be clearly displayed on UI (I was not able to find it).

            ¯\_(ツ)_/¯

            1 Reply Last reply Reply Quote 2
            • idefix37I
              idefix37 Sailor Moderator @Gkikas LGPZ
              last edited by idefix37

              @Gkikas-LGPZ
              It was quite obvious for me that the isobars cannot match perfectly the satellite layer. And to get the best compromise it is necessary to set first the timeline on the current time. But I agree with you, that could be done automatically by Windy. From a theoretical point of view, it is wrong to mix forecast and observation. So in this case, Reported wind and Reported temperature should not been displayed at same time with all forecast layers. They show crazy values if the timeline is set 12 hours ahead and more... Windy needs a bit of understanding and training.

              1 Reply Last reply Reply Quote 2
              • jmh2002J
                jmh2002 Moderator Mariners - Seafarers Sailor
                last edited by

                From a development point of view:

                • Should there be some type of pop up warning about mixing these combinations of layers together?

                • Or should it just be impossible to mix these combinations in the first place?

                What are everyone's thoughts about this?

                WINDY is everywhere :)

                Gkikas LGPZG idefix37I 2 Replies Last reply Reply Quote 0
                • Gkikas LGPZG
                  Gkikas LGPZ Moderator @jmh2002
                  last edited by

                  @jmh2002
                  My opinion:
                  Satelitte layer must be "mixed" with isobars and/or other isolines
                  ONLY if those isolines reffer to the time of sat. image (plus/minus 1 hour).
                  I agree with idefix37 that theoretically is wrong to mix forecast and observations
                  but practically I like to have sat. + isolines (isohypses) at 850 or 700 hPa
                  to predict the direction of thunderstorms movement.

                  1 Reply Last reply Reply Quote 2
                  • vsinceacV
                    vsinceac | Premium
                    last edited by vsinceac

                    I think the best would be to clearly display on UI the validity time of the static data displayed on isolines layer (pressure, temperature, etc.).
                    This way I think nobody would say that it is a bug: users should easily understand this.
                    It is the same as when displaying a time series of observed data today AND of the data observed one year ago, on the same 2D plot; this is often used in analysis and it is really useful when the validity time of each time series is clearly labelled.

                    ¯\_(ツ)_/¯

                    1 Reply Last reply Reply Quote 2
                    • idefix37I
                      idefix37 Sailor Moderator @jmh2002
                      last edited by idefix37

                      @jmh2002
                      I don’t think a warning pop up would be a good idea (it is not in the Windy culture). IHMO it could be done automatically when isobars are selected together with satellite layer i.e. isobars should be displayed at about same hour as the last satellite observation as @Gkikas-LGPZ said.
                      I think this is possible in the same way as when you select Rain accumulation with ECMWF at 10 days and switch to ICON, the time lapse is automatically set back to 12h.

                      1 Reply Last reply Reply Quote 2
                      • jmh2002J
                        jmh2002 Moderator Mariners - Seafarers Sailor
                        last edited by

                        @Korina @developers

                        Please review these last comments and note and discuss with the development team regarding how this can be improved, thank you :)

                        WINDY is everywhere :)

                        KorinaK 1 Reply Last reply Reply Quote 1
                        • KorinaK
                          Korina @jmh2002
                          last edited by

                          @jmh2002 @idefix37 @vsinceac Hi all, it seems as a bug, I will let our development team know. Thank you for reports!

                          Korina

                          1 Reply Last reply Reply Quote 3
                          • P
                            peteraschindler | Premium
                            last edited by

                            You mention that NEMS is only available in Europe.
                            But, I'm based in Hong Kong, and METEOBLUE is shown, besides GFS and ECMWF, as models for this location.
                            Why?
                            Thank you!
                            Peter S

                            KorinaK idefix37I 2 Replies Last reply Reply Quote 0
                            • KorinaK
                              Korina @peteraschindler
                              last edited by

                              @peteraschindler Hello, NEMS is a local weather model created by Meteoblue. Meteoblue model is only available in the detailed forecast and yes, it is global model.

                              Korina

                              1 Reply Last reply Reply Quote 0
                              • idefix37I
                                idefix37 Sailor Moderator @peteraschindler
                                last edited by

                                @peteraschindler
                                Find here additional information about the difference between NEMS and METEOBLUE. It is called Meteoblue AI by this forecast provider:
                                https://community.windy.com/topic/10316/metoblue-wildly-inaccurate-in-the-sw-usa/4?_=1588859394205

                                1 Reply Last reply Reply Quote 0
                                • Yves70Y
                                  Yves70 Meteorologist | Premium
                                  last edited by

                                  @peteraschindler
                                  Meteoblue is a Swiss company who developped a global model called NEMS. With this model, you can get weather forecast all over the world as this a global model, as GFS for instance.

                                  1 Reply Last reply Reply Quote 0
                                  • J
                                    jerryw @Zeeshi7897 | Premium
                                    last edited by

                                    @Zeeshi7897

                                    1 Reply Last reply Reply Quote 0
                                    • Y
                                      yqw
                                      last edited by

                                      What is the data source for satellite? How does Windy get it from EUMETSAT?
                                      1.png
                                      If it is EUMETCast Satellite Europe - Ku-band than what do you get from it?
                                      2.png
                                      Does Windy pay EUMETSAT for it?
                                      alt text

                                      KorinaK 1 Reply Last reply Reply Quote 0
                                      • KorinaK
                                        Korina @yqw
                                        last edited by

                                        @yqw Hello, the source is Eumetsat and data are displayed based on the contract.

                                        Korina

                                        1 Reply Last reply Reply Quote 1
                                        • T
                                          TTurbyfill8 @A Former User | Premium
                                          last edited by

                                          @sv1aaw That would be great. WU was extremely accurate until Weather.com bought them and they dismantled the PWS network. I am in Central America and the WU 6 hour graphic forecasts could be relied upon. It was a game to see how accurate they were to the quarter hour.

                                          1 Reply Last reply Reply Quote 0
                                          • howardkuoH
                                            howardkuo
                                            last edited by

                                            Is it possible to default to NAM instead ECMWF?

                                            idefix37I 1 Reply Last reply Reply Quote 0
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