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    Why is Wind speed in hurricanes so wrong?

    Frequently Asked Questions
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    • S
      Siff
      last edited by

      I also want to point out that why isn't real data being positioned at the old prediction data points. How do you check your accuracy then based on the predictive algorithm to the real data? Why was there no mention of this before putting up this site, seeing that the public has access to this site?

      M F 2 Replies Last reply Reply Quote 0
      • S
        Siff
        last edited by

        As a side note I checked the accuracy of this by going to my location and checking all data and it is very accurate when compared to current temps and pressure and winds.

        1 Reply Last reply Reply Quote 2
        • S
          Siff
          last edited by

          fyi:

          "

          Scientists have a new way to measure how fast the wind is blowing.

          That's because over the past decade, scientists have learned how to measure the speed of the wind at the ocean's surface by observing how much GPS signals are distorted when bouncing off the moving water waves. Now, a new paper reports that such wind speed measurements can be used with confidence when conditions are right, even to measure the winds of hurricanes.

          Improved wind speed measurements could help meteorologists better understand and predict storms, says Stephen Katzberg, a distinguished research associate at the NASA Langley Research Center in Hampton, Virginia.

          In the early 1990s, Katzberg and colleagues at NASA were asked to evaluate a U.S. Navy satellite for a civilian application in global ocean altimetry. The U.S. Navy was beginning to use GPS in their satellites and the team became intrigued with the question of whether the GPS signals could reflect off the surface of the ocean.

          "Normally GPS signals go to a receiver in your car or cell phones, but some of it reflects off surfaces," Katzberg told National Geographic. "It's an incidental thing that turns out to be pretty practical, especially because GPS now illuminates pretty much the entire Earth."

          Ricky_LightningR J 2 Replies Last reply Reply Quote 1
          • I
            Incubeus
            last edited by

            So what are you suggesting is that Windy.com is more for entertainment purposes than an accurate monitoring tool? if so, that's a damn shame. Time to go back to the traditional radar resources, you know... the ones that are accurate.

            1 Reply Last reply Reply Quote 2
            • S
              Siff
              last edited by idefix37

              Technology that they use for satellite measurements is actually the GPS system and special x-ray detectors. The technology is already there and being used for this additional purpose. That is why I included the information about how they get the measurement data. GPS is already being used extensively and the resultant reflection off of the water let them calculate the movement of said water. The GPS signal is reused for this purpose. Now you are trying to tell me they are getting rid of the GPS system? I highly doubt that.
              I also agree that if the system is not accurate in real time then what data are you feeding it every morning, noon and night and why is the data over my own location so accurate when they use the very same systems to show our current weather. In fact they enhance the system using GPS and the local overland radar is fed into the data as well. I don't understand this explanation that they are cutting the funding....
              Is windy.com using real data or not and what is the discrepancy between the real time data and current data from the ground sources. Why would the system be so accurate overland but very "Smoothed" over the water?
              Why is there a 100 mph difference between the current data shown on your system and the reported data from the media..
              They are saying this storm is 185 mph sustained wind with 225 gusts, yet your data is 100 mhp slower.

              S 1 Reply Last reply Reply Quote 1
              • S
                Siff @Siff
                last edited by

                @Siff

                Sorry some corrections here. Not x-ray but microwave satellites.

                1 Reply Last reply Reply Quote 0
                • O
                  oldman77
                  last edited by

                  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

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                  • D
                    DailyRich @oldman77
                    last edited by

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

                    Toobie78T M 2 Replies Last reply Reply Quote 0
                    • jurate2911J
                      jurate2911 | Premium
                      last edited by

                      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

                      1 Reply Last reply Reply Quote 1
                      • georgewellsG
                        georgewells
                        last edited by

                        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?

                        F R A 3 Replies Last reply Reply Quote 1
                        • Toobie78T
                          Toobie78 @DailyRich
                          last edited by

                          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.

                          1 Reply Last reply Reply Quote 1
                          • M
                            markholbrook64 @DailyRich
                            last edited by

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

                            1 Reply Last reply Reply Quote 1
                            • kf4nxsK
                              kf4nxs
                              last edited by

                              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.

                              1 Reply Last reply Reply Quote 0
                              • M
                                MeteoMike686 @Siff
                                last edited by

                                @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.

                                1 Reply Last reply Reply Quote 1
                                • stevecryeS
                                  stevecrye @TZ | Premium
                                  last edited by

                                  @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

                                  Gkikas LGPZG 1 Reply Last reply Reply Quote 13
                                  • Gkikas LGPZG
                                    Gkikas LGPZ Moderator @stevecrye
                                    last edited by

                                    @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

                                    Gkikas LGPZG 1 Reply Last reply Reply Quote 4
                                    • Gkikas LGPZG
                                      Gkikas LGPZ Moderator @Gkikas LGPZ
                                      last edited by

                                      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

                                      Ricky_LightningR 1 Reply Last reply Reply Quote 1
                                      • F
                                        frostymon @Siff
                                        last edited by

                                        @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.

                                        1 Reply Last reply Reply Quote 2
                                        • F
                                          frostymon @georgewells
                                          last edited by

                                          @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.

                                          J 1 Reply Last reply Reply Quote 3
                                          • N
                                            nolan0019
                                            last edited by

                                            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.

                                            1 Reply Last reply Reply Quote 0
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