Why is Wind speed in hurricanes so wrong?



  • I use the wind Gust icon and this seems to be very close to the TV info. Once I get past the "Eye" it must be affected by the info that you indicated
    Ron



  • So if I see a wind speed of 180 / 35mph, what does that mean exactly? What's that first number?



  • I really like this tool and hope the team can develop to be as accurate as possible. Wishing this team all the best. This tool is my secondary. I have built a map by putting all traditional sources together. with both of these tools, we can monitor and compare the data easier.
    http://www.arcgis.com/apps/View/index.html?appid=7eaab00a59954a03b952e44e0150844a



  • News agencies across the World are reporting Irma's wind speeds up to 185MPH. How is it that they all know the wind speeds but Windy.com and the Windy app do not?

    I have yet to see Windy show Irma's wind speeds any greater than 80MPH. That makes the app useless. How can any of Windy's numbers be trusted with such grievous errors?



  • The first number is the compass heading. 0 means the wind is out of the north (blowing to the south), 90 is east, 180 is south, & 270 is out of the west.



  • @DailyRich First number is wind direction. 0=north, 180=south etc.



  • You have to remember, depending on the model you are using those are the values at Height. IE 10mAGL is apx 33 ft above Ground Level, some model are at 9k feet and some higher. 10m is about as close to ground level as you can get with model software, and there is all kinds of factors at ground level that can change the wind values. Homes, trees, vehicles, even porches can effect an accurate wind speed at ground level.



  • @Siff Where do you get the real data from for everywhere on the planet? It's easy to say you have real data in somewhere like the USA, which is covered by hundreds of observation points, along with upper air measurements taken twice daily. What about everywhere else?

    How do you verify a forecast for a location which there is no credible observation data? Remote sensing can help, but it only goes so far.



  • @TZ 100% correct TZ. Others in this thread clearly don't understand weather modeling. Windy pulls the model data - NAM 3k, ECMWF 9k or GFS 22k - from NOAA and other agencies and then displays it on a great GUI - all 100% free. Windy does not generate model data. Prior to Windy I was forced to look at the raw data - ugh. I'm hoping soon that Windy can also show other "popular" models such as HRRR, OP4-, BAK40, etc. Also, a skew-t at a click would be wonderful! Keep up the good work. Windy is an invaluable tool for pilots and sailors, who use it every day. As for the haters - take the time to learn how to use Windy - for example, I just now selected Wind Gusts and see 155 MPH near the eye of Irma - very accurate. And study meteorology , it might help you get a clue ... if all that fails, go use some other app/website, most are not free.

    Steve


  • Moderator

    @stevecrye
    You are absolutely right!
    Windy is the best "tool" for visualization of weather models and the only one that provides, for free, data from the ECMWF. Unfortunately some people cannot distinguish model data (forecasted values) from real measurments (observations). And some others even expect to have forecast radar images !!! ignoring that radar "can see" only what happens now ... forecast models "visualize" the future (with all the inaccuracies that include).
    P.S. sorry for my poor english


  • Moderator

    If someone wants to compare actual wind measurements with model's outputs:
    Here can find ocean wind measurements from scatterometer (satellite instrument)
    https://manati.star.nesdis.noaa.gov/datasets/ASCATBData.php



  • @Siff , it is mentioned in the about section. It says the site uses three weather models. i don't see why you feel they need to spell out the things they do not use.



  • @georgewells , news agencies are most likely getting their data from the National Hurricane Center, who are in turn getting their wind speed data by flying an airplane into the storm. This website relies on a few standard models to present it's graphics, not actual observations.



  • Siff mentioned that he had been comparing weather station data to Windy's reported surface winds and they agreed. I too have been doing this following Irma (I live in Orlando). I went to weather channel or other local weather data for a location and compared it to Windy and they did seem to be very close (for wind speed). Weather stations measure the actual wind speed from instruments that are 10m off the ground (http://www.wral.com/weather/blogpost/1283652/). I would assume that the reported hurricane wind speeds are measured the same way, but I agree that there’s a big disparity between the reported speed and Windy’s speed. Another very similar site, www.ventusky.com, has the same disparity.



  • I don't care about the politics for sure. I also think this is a great graphic to indicate what's happening and going to happen. Whether there is some error in the system of 20 or 40 %, it's a great way to show laymen some technical information that isn't a bunch of stuff that only engineers, meteorologists, or geniuses can comprehend. GREAT JOB



  • Windy needs to get the Winds right... kind of a poetic necessity. :)

    I agree with many that that the wind data sets (wind & wind gusts) are are not easy to nail at all - let alone consistently. But I truly believe it needs to be mastered over time... especially in the angry weather world we have brought ourselves.

    I think Ventusky is making a good effort here (though not sure on data accuracy audits re wind).

    When Cat5 Matthew rolled thru Florida last year - the wind data projections were wildly off the further out from the storm centers.. useless actually.

    When I looked that the micro-local Dark Sky wind speed projections... they were spot on.

    I think that (in the end) there needs to be a artful balance between macro and micro data. That said: when you are in a storm - most want to know what is going to happen to me where I am... and those we love.

    Master the winds... Windy!

    Stay safe everyone....



  • @Mekronid Oh please DO stop your rant against Trump. Or show your sources.



  • Windy states very clearly that winds are arrived at using all relative, applicable and resourceful data and they are defined. The arrows represent wind velocity, (relative speed and direction), within a certain volume suspended above the surface. There may be a billion directions and speeds in that volume, but the one chosen represents the speed and direction expressing the central or typical value in a set of data, in particular the mode, median, or, (most commonly), the mean.****

    IMO windy is a great tool-very discerning engineering.



  • Steve, this is great and I thank you (I live in Florida)
    A better work around is take the measurement at 100 meters or 500 meters.
    This is a compromise of sorts.
    This is a worthwhile project and may save many lives here.
    I am reposting on Facebook with some editing. all the tool bars and are can be distracting. I wish you could do false colour white green and blue.

    THank you.



  • @Mike-Boyle
    If you need any help in evaluation let me know.
    I'm a retired electronic/ computer technician.
    Boylemike1@aol.com


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