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    Conflicting swell height in models

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    • L
      Ljos last edited by

      Regularly there is a very marked difference in the swells reported
      by the ECMWF, GFS and ICON. For instance, in the Atlantic Ocean east of the Caribbean Islands (17, -61), models show same wave height; however both models will show a significant difference in the swell heights. The ECMWF and ICON will show swell heights of 7 feet and the GFS will show swell heights if 0 feet. Is this an issue in the resolution or parametrization used between models?

      Korina 1 Reply Last reply Reply Quote 0
      • Korina
        Korina Administrator @Ljos last edited by

        @ljos Hello, could you please enclose a screenshot?

        Korina

        1 Reply Last reply Reply Quote 0
        • L
          Ljos last edited by

          Hi there sure. Sorry I just saw your post . The information may be slightly different because of model update. Notwithstanding, the discrepancy continues. Here is a screen shot of ECMWF

          6fffef9c-5385-4894-8270-ab6372dc0544-image.png

          Here the GFS screenshot
          3f4c67ec-1866-4dc1-beeb-211c5fdf1d42-image.png

          Here is the ICON model screenshot
          53bc4cc3-4818-4530-b8bc-ae621f1e58ed-image.png

          Please note that at the reference point the Swells for the
          ECMWF is 5-8 feet
          GFS is 0-3 feet
          ICON is 6-8 feet

          Clearly something is going on for such a large discrepancy between the GFS and the other models .

          Will await your response
          Ljos

          Korina 1 Reply Last reply Reply Quote 0
          • Korina
            Korina Administrator @Ljos last edited by

            @ljos Hello, each forecast model can produce slightly different values, therefore such differences are not discrepancies.

            Korina

            L 1 Reply Last reply Reply Quote 0
            • L
              Ljos @Korina last edited by

              @korina Hi Korina thanks for your response. I accept what what you mentioned; however the difference you point out is not a one day occurrence; it is consistent - model run after model run; so that's the reason why I describe it as such.

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

                @ljos
                It seems that GFS wave model shows weaker swell heights compared to ECMWF and to DWD wave models (both uses WAM model but with probably minor changes and forced by 2 different wind models, IFS and ICON).
                These screenshots from yesterday show a big difference of swell heights in the overall tropical part of the Atlantic and in other areas.

                EBCAE47B-12E0-429E-A702-6A6BE69DD077.jpeg

                DB2711AA-F211-47A6-8256-1D22F78CC538.jpeg

                Is it a wrong visualisation from Windy? Probably not because at same time the NOAA shows the same swell map from GFS but with a different color scale (deep blue is less than 0.5m which corresponds to light blue in the Windy color scale)

                A4A0E485-9FC0-4BBD-8435-25E8AF888AF5.png

                Finally which the best model for predicting Swell? Difficult to say. But I remember good prediction of ECMWF in european seaside.

                1 Reply Last reply Reply Quote 1
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