Problem: Wind spot forecast differs from animation



  • I'm seeing the wind spot forecast heading not match the animation. See these two snapshots, one using ECMWF the other WAVEWATCH:
    0_1530370614175_Screen 2018-06-30 028_sml.png
    Full size: https://www.dropbox.com/s/b8lls0a3hn03bz5/Screen 2018-06-30 028.png
    0_1530370720409_Screen 2018-06-30 029_sml.png
    Full size: https://www.dropbox.com/s/u50f1vxor7s18eb/Screen 2018-06-30 029.png

    It kind'a looks like the animation and the spot forecast use different models? Really confusing.
    ull size:


  • Sailor

    @tve
    When you choose the ECMWF model for the wind and ECMWF WAM for the waves the result is consistent. But with ECMWF for the wind (the animation) if you switch to WWW3 wave model, it cannot match because WWW3 use an other wind model.
    When you change the wave model it does not change automatically and accordingly the wind model (the animation).



  • How do I select the wind model and where do I see which is selected? It seems a bug to me that what is shown is not consistent. Also, I posted two images one using ECMWF WAM and one using WWW3 and in neither do the wind directions match the animation (in addition none of the three matched reality , the wind ended up coming out of the WSW!).



  • I gave it another try. Step 1: display the wind, note ECMWF model:
    0_1530390748486_Screen 2018-06-30 032.jpg

    Then I switched to waves (ECMWF WAM) and placed a detail spot marker:
    0_1530390804459_Screen 2018-06-30 033.jpg

    Then I switched back to wind and the animation (which is the same as in step 1) does not match the wind direction of the spot marker:

    0_1530390869875_Screen 2018-06-30 034.jpg

    Is this Windy showing inconsistent data or is this due to the data sets not being self-consistent?


  • Sailor

    @tve
    Concerning the difference between the forecasted wind and the wind that you observe, as you are on the sea shore, you may have local winds, thermal winds ... that global models cannot predict in light winds conditions. It’s better in this case to use a higher resolution model like NAM.
    I have tried again in you area to make the same comparison that you have done, but for me the results are consistent. Check that you did not had a pop up like this ( but it’s with NEMS model)

    0_1530446375540_B100C43A-C281-4EB2-8850-48510816CBCD.jpeg

    You may do the following checking near the Tropical Storm «Fabio» which will strengthen to Hurricane degree by Thursday and will be located N 18º W 125º approx. (It’s better to do this exercise at this date to have different directions of wind forecasted by the models)

    0_1530447217905_5AA066ED-5935-4910-9956-BC64357245C3.jpeg

    In the weather diagram for a place near this storm choose « Basic » and select ECMWF, then switch to « Waves » and select ECMWF WAM, the wind direction on the map and the wind in the light blue label must be the same.
    Then do the same with GFS and WaveWatch, the directions must be consistent. 0_1530447707737_E957D2B0-A0EB-40B1-BBB4-67B16291641A.jpeg

    Of course if the wind model and the wave model don’t match, the result is wrong.
    0_1530447833880_AC9624D3-EF32-4C6F-9D69-21DFB36A08B7.jpeg

    You should obtain the same results as me. Otherwise there is an issue with the device used ??


  • Sailor

    @tve
    In addition, the information about Tropical Storm « Fabio » in West of Mexico are from NHC



  • @idefix37 I understand that when I use different models the outcome isn't necessarily the same, but in my example I specifically used ECMWF for both.


  • Administrator

    WIll look at this


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