Description of weather overlays


  • Sailor

    @meridies
    @Eand

    As you probably know the shape of waves, in a given place, is a mix of different kind of waves:

    • The windsea (also called wind waves) is produced by the local wind.

    • The main swell is produced by a strong wind far away.

    • Secondary swells are produced also by winds far away but in other places.

    All of them have different heights, come from different directions and show different periodes (which is the time between 2 wave crests)
    Swell 1 is the main swell, swell 2 and 3 are secondary swells (the swell classification 1, 2, 3 depends on their respective heights)
    In this example below, Wind gives the direction of windsea. Swell 1 has a height of 0.6m and a period of 9 seconds.

    0_1532433836586_C4D96B18-4CD9-49E4-8BCE-75D80F835ACE.jpeg

    The best surf conditions correspond to a strong swell with weak windsea and secondary swells.

    A cross sea thrown up by a strong wind and a strong swell whose directions make an angle close to 90º gives hard conditions for navigation.



  • Also it would be appropriate to post a legend up on the main page about what each of the layer icons represent. In this list of descriptions there are no corresponding icons. The names of the layers did not appear in the version of Firefox I was using.



  • @gkikas-lgpz I am just working on it. Coming soon both in this post and on windy.com >> "about these data" section ("clock" icon).



  • Hi ,
    I am trying to get data related to weather overlays()wind,wave height,current,current direction) in my application. My input parameters would be lat,long and datetime. Can anyone please advise how to implement using windy api



  • Is there a description of Wind Accumulation? Seems like it would follow this description from above

    "Rain accumulation: Total rain accumulation in the next hours or days."

    But I am seeing it change for the path of Hurricane Florence southward along the South Carolina and Georgia coasts, which matches the spaghetti model's adjustments I've seen as well.

    Is Wind Accumulation an indicating factor in those models I guess? Also is there a plan to add those as a layer to the Windy interface?

    Just added the app and started recommending to friends - very much enjoying it so far!


  • Sailor

    @elmo19
    I’ve just discovered the Wind accumulation today, thank to your question !
    I don’t know if I’m right, but for me this layer is the wind accumulation on 10 days (?) for the model you have selected, nothing to do with «Spaghetti models » (that I prefer calling Multimodels forecast). It is probably not either the Ensemble Model, but just the standard Deterministic Model that is selected i.e. ECMWF, GFS or NAM. But this is to be confirmed.



  • @idefix37
    What is "wind accumulation" ?
    I can not find any definition here
    http://glossary.ametsoc.org/index.php?title=Special:AllPages/W

    I've (also) just discovered this parameter and I see that is not changing
    for the whole forecast period.

    It reffers to the max wind for the forecast period?
    or to mean direction and wind speed for the forecast period?

    We can accumulate rain or snow, but ... wind? Is not stacked !



  • @gkikas-lgpz It is maximum intensity projection - means that maximal value of the forecast period is taken for each point.


  • Sailor

    @tz
    @Gkikas-LGPZ
    Thanks, but strange that there has been no announcement and explanation for this new layer.
    It’s a way to predict the track of a strong and localised storm that’s OK. Is « Wind accumulation » the best name for this layer? But I’ve not another name to propose.



  • @idefix37 It was released quickly because of the current hurricanes and typhoons. Probably some adjustments will be made and we will also add the description.


  • Sailor

    @tz
    Sorry the announcement was in the next post !


  • Sailor

    @TZ
    Today there are 2 storm tracks in the North Atlantic:
    One is the track of Helene. The second one, it seems impossible to identify what makes it
    (Note that the tracks are black on my screen because I changed the wind colour settings: strong winds are black for me)

    0_1537039405024_234DA710-0391-46DD-A285-B224D5F1904E.jpeg

    On this track there is e.g. 154km/h at this point: N 57º16’ W16º36’.
    If the time slider is moved over the 10 days there are only 2 maximum at the same point: 95km/h on Wednesday and 104km/h on Sunday.
    So, how is it possible to have 154km/h and what is the explanation of this narrow track when there is no localised storm?



  • @idefix37 Hi, is it still there? Maybe it is a bug, I will look at it, but the computation is pretty straightforward.


  • Sailor

    @tz
    Hi,
    Today there is no similar strange track. I have checked one or two tracks in the North Atlantic. They seem to correspond correctly to the max. gusts predicted in the same area once during the 10 days.
    A suggestion: sometime the track is due to a strong wind at day 8 or 9. For people it will be difficult to understand why they see this storm track if the strong winds are forecasted at near the end of the 10 days.
    So, instead to show the wind speed in the picker, may be it would be better to show the date when the max. gust is expected ?



  • @idefix37 We will consider it, but for our user interface it would be better to add 3/5/10 range selector like in rain accumulation.



  • @tz
    Totally agree!
    I suggest "wind accumulation" to include only 3 and 5 days range.
    Inaccuracies beyond day 5, are big.
    Even NHC, tracks hurricanes up to day 5.



  • @tz sagte in [Beschreibung von Wetter-Overlays] (/ post / 7549):> @IgorXXXmirror Hallo, 100m Schicht oben Modell Gelände.



  • @sonnigekerstin I would like to know how to decode the cloud symbols on the meteogram. Most are obvious, however some less so. For example, the four stacked horizontal gray horizontal lines? thanks


  • Sailor

    @edneff
    These lines correspond to altitude levels. They allow to know the altitude of the clouds shown on the Meteogram.

    0_1544470068774_A7488F1C-2A99-4CA1-ADCB-5D465CB52268.jpeg

    • 700h means 700hPa. This altitude is expressed as atmospheric pressure level.

    • 3km is the altitude in metric

    • FL100 is used by aviation as flight level. FL100 correspond to 10000ft level.



  • @idefix37 said in Description of weather overlays:

    @tz
    Hi,
    Today there is no similar strange track. I have checked one or two tracks in the North Atlantic. They seem to correspond correctly to the max. gusts predicted in the same area once during the 10 days.
    A suggestion: sometime the track is due to a strong wind at day 8 or 9. For people it will be difficult to understand why they see this storm track if the strong winds are forecasted at near the end of the 10 days.
    So, instead to show the wind speed in the picker, may be it would be better to show the date when the max. gust is expected ?


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