What source of weather data Windy use?
How do you "add pressure" to "satellite" layer?
These two data layers should exclude each other afaik.: one is real time observation, the other is computed forecast, then they could very rarely have same timestamp on the timebar.
From my pov., if they display together, there is a bug, as they cannot be contemporary.
When you choose Satellite, with pressure isolines or without, the provider is shown in the right low corner. Eumetsat is the provider of satellite data. You can click on it to get information.
In the same way you get the providers of Radar layer data per country.
Pressure isolines (isobars) are always from ECMWF.
I think there is a problem here
because when in satellite and activate "pressure"
the isobars are those from the last session.
must try to replicate the following:
Now, 12 May/23 Local (20 UTC) there is a high pressure ridge over Morocco
..... I go forward at (let say) Sat 16 May (20 UTC)
there is a 1021 hPa High over Morocco......
if I go to satellite layer and activate pressure isolines (isobars)
I see those for Sat 16 May !!! with the 1021 hPa High over Morocco
(although sat. image is for today 12 May).
As said in my previous post above, if forecasts and satellite image layers are displayed together on map, there would be a bug: they cannot be contemporary (excepted at full hours, maybe).
Satellite images are provided every 10 or 15 minutes; Windy should obtain that worldwide mosaic by merging images from differrent satellites, taken at small time difference (a couple of minutes or so, but surely not hours).
When combining satellite and atmospheric pressure layers together on map, then playing the animation over the whole available period on timebar (i.e. last 2, 6 or 12 hours), one can see that the pressure layer remains static over the whole period, while satellite images layer change at each time step...
Thus the pressure isobars layer doesn't follow current value on timebar as expected, which is wrong from my pov.
Having a static pressure isobars layer combined with animated satellite images would be useful for some specific deep analysis, but in such a case the validity time of the static layer should be clearly displayed on UI (I was not able to find it).
It was quite obvious for me that the isobars cannot match perfectly the satellite layer. And to get the best compromise it is necessary to set first the timeline on the current time. But I agree with you, that could be done automatically by Windy. From a theoretical point of view, it is wrong to mix forecast and observation. So in this case, Reported wind and Reported temperature should not been displayed at same time with all forecast layers. They show crazy values if the timeline is set 12 hours ahead and more... Windy needs a bit of understanding and training.
From a development point of view:
Should there be some type of pop up warning about mixing these combinations of layers together?
Or should it just be impossible to mix these combinations in the first place?
What are everyone's thoughts about this?
Satelitte layer must be "mixed" with isobars and/or other isolines
ONLY if those isolines reffer to the time of sat. image (plus/minus 1 hour).
I agree with idefix37 that theoretically is wrong to mix forecast and observations
but practically I like to have sat. + isolines (isohypses) at 850 or 700 hPa
to predict the direction of thunderstorms movement.
I think the best would be to clearly display on UI the validity time of the static data displayed on isolines layer (pressure, temperature, etc.).
This way I think nobody would say that it is a bug: users should easily understand this.
It is the same as when displaying a time series of observed data today AND of the data observed one year ago, on the same 2D plot; this is often used in analysis and it is really useful when the validity time of each time series is clearly labelled.
I don’t think a warning pop up would be a good idea (it is not in the Windy culture). IHMO it could be done automatically when isobars are selected together with satellite layer i.e. isobars should be displayed at about same hour as the last satellite observation as @Gkikas-LGPZ said.
I think this is possible in the same way as when you select Rain accumulation with ECMWF at 10 days and switch to ICON, the time lapse is automatically set back to 12h.
You mention that NEMS is only available in Europe.
But, I'm based in Hong Kong, and METEOBLUE is shown, besides GFS and ECMWF, as models for this location.
@peteraschindler Hello, NEMS is a local weather model created by Meteoblue. Meteoblue model is only available in the detailed forecast and yes, it is global model.
Find here additional information about the difference between NEMS and METEOBLUE. It is called Meteoblue AI by this forecast provider:
Meteoblue is a Swiss company who developped a global model called NEMS. With this model, you can get weather forecast all over the world as this a global model, as GFS for instance.
What is the data source for satellite? How does Windy get it from EUMETSAT?
If it is EUMETCast Satellite Europe - Ku-band than what do you get from it?
Does Windy pay EUMETSAT for it?
@yqw Hello, the source is Eumetsat and data are displayed based on the contract.