West Africa rain data way off
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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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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 :(
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@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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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.
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@Jibi
This is the satellite observation a 10:00 UTC (INFRA+ showing temp at top cloud)
That can be compared to Cloud forecast at same time (Cloud+rain amounts for 3 hours)
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)
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.
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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 :)
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@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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@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.
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@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.
(with customized colors)
