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    West Africa rain data way off

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    • J
      Jibi
      last edited by

      Hi. I just dicovered this excellent-looking site and app. I live in West Africa and I find that your visual rain data is way off. It shows active rain in areas that have no clouds, and nothing where there are tropical storms in progress. EUMETSAT data is very accurate here though. Can you use that data?
      Jibi

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      • J
        Jibi
        last edited by

        Actually, looking closer, a lot of your data on West Africa is off. The wind is blowing the wrong way, the cloud data is wrong etc. etc. Compare the weather data to the visual satellite images and you'll see it's not even close :(

        idefix37I 2 Replies Last reply Reply Quote 0
        • idefix37I
          idefix37 Sailor Moderator @Jibi
          last edited by idefix37

          @Jibi
          You compare observation (satellite images) with rain and wind forecasts. The satellite observation are accurate, the weather forecasts not so much. Windy visualizes 2 weather models, ECMWF and GFS. Are they both so wrong?
          Note that EUMETSAT does not provide weather forecasts data like rain or wind.
          Then the wind at ground surface is not exactly the same as the clouds motion in altitude that you observe with satellite.

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          • J
            Jibi
            last edited by

            Thanks for your reply. I appreciate the difference between observation and forecast. But even at the current time, both forecast models show large amounts of cloud where there is none, no cloud where there is cloud, and wind blowing west to east across most of West Africa, when it generally blows the opposite direction, as it is now.

            idefix37I 1 Reply Last reply Reply Quote 0
            • idefix37I
              idefix37 Sailor Moderator @Jibi
              last edited by idefix37

              @Jibi
              This is the satellite observation a 10:00 UTC (INFRA+ showing temp at top cloud)

              B025A6A9-4E2F-4894-BC21-B9E6A9214CF5.jpeg

              That can be compared to Cloud forecast at same time (Cloud+rain amounts for 3 hours)

              25D2EF4D-08EF-425E-9EE7-B0324301028A.jpeg

              It seems not so bad at this zoom level.

              Concerning the wind I do not see a general direction west to east at ground level except in West Africa
              (Wind layer with customized colors)

              414DE0EA-322A-441F-B467-0E7A9F11FB04.jpeg

              At 500hPa altitude the forecasted wind is east to west, same as the motion of cloud on satellite image and as the usual intertropical flow.

              B0360F7C-99A5-47EA-9CC0-46B4D93BB963.jpeg

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              • J
                Jibi
                last edited by

                Thanks for looking into it. I appreciate seeing the different wind patterns at different altitudes. We had a large tropical storm over our region in southern Maurtiania last night, while your app showed no rain. This morning we had clear skies and your forecast told me it was raining hard. I don't know anything about the science of weather prediction, but I appreciate your efforts :)

                idefix37I jmh2002J 2 Replies Last reply Reply Quote 0
                • idefix37I
                  idefix37 Sailor Moderator @Jibi
                  last edited by idefix37

                  @Jibi
                  So it was a timing issue. Forecast was a bit late.
                  BTW I’m just a Windy user like you, so your thanks are for the Windy team.

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                  • jmh2002J
                    jmh2002 Moderator Mariners - Seafarers Sailor @Jibi
                    last edited by

                    @Jibi said in West Africa rain data way off:

                    Thanks for looking into it. I appreciate seeing the different wind patterns at different altitudes. We had a large tropical storm over our region in southern Maurtiania last night, while your app showed no rain. This morning we had clear skies and your forecast told me it was raining hard. I don't know anything about the science of weather prediction, but I appreciate your efforts :)

                    Pleased that @idefix37 was able to additionally explain things for you.

                    Also, to clarify further, Windy does not create any forecast data but instead only visualises forecast and actual data received from various third party providers.

                    For Africa this includes ECMWF and GFS for forecast data, and EUMETSAT for satellite images.

                    There is no forecast created by Windy.

                    WINDY is everywhere :)

                    1 Reply Last reply Reply Quote 1
                    • idefix37I
                      idefix37 Sailor Moderator @Jibi
                      last edited by

                      @Jibi
                      At least concerning the Wind, you can use Reported wind which are weather stations observations and compare them to the wind forecasts at actual time. I find the Wind layer forecast quite good.

                      724D8A41-31FA-41A9-BF36-C4D45568CE04.jpeg

                      (with customized colors)

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