@yves70 Yeah, I know the data in Premium and free version are different (1h v.s. 3h). But the question is...I just want to make sure that the definition of the rainfall value shown on the layers and meteogram is still the same? Thanks for your help!

@yves70 said in Description of weather overlays:

@baldo1191
I understand that you can be surprised to see those differences although you should not.
There are different elements :

1. the figures after the coma have not a lot of meaning so 7.4mm could be easily 8mm and on 9.8mm could be easily 9mm. Of course it could be 7mm and 10mm as well
2. what the picker is showing is rain accumulation, this is the equivalent to the data from the map called rain accumulation. The data in the meteogram and data from rain accumulation are both calculated by the model, meaning that by definition you can get different values knowing that on top of this difference, Windy is smoothing the data which will also affect a bit the data.
   The conclusion is that you should take that as a nice opportunity to get 2 sets of data for rain accumulation, so in your example you can guess that rain accumulation could be somewhere in the middle so around 8.5mm. It is a bit the same approach as comparing the data from 2 different weather models

@yves70 Thanks for your interpretation, I've already been confused by this disagreement for a long time, too! Finally find a reasonable answer here.
The one thing I'd like to confirm is whether the rainfall values on the basic forecast and Meteogram still represent the precipitation accumulated from the previous hour (or in the last 3-hr)?

And I'd also like to know whether the value of 'rain' in Meteogram actually represents the large-scale precipitation or not? Since the total precipitation is the sum of large-scale & convective precipitation in both ECMWF & GFS, according to their paramter description. It seems that the total amount of precipitation has been split into two parts in the bar graph in Meteogram: the large-scale term and convective term. Furthermore, the sum of 'Rain' and 'Covective' is exact the value in basic list, which might indicate the total precipitation. Does it indicate the term 'Rain' might be equivalent to the large-scale precipitation in Meteogram?

Thanks again!

@korina Thanks for your help! Yes, I know exactly the data in Premium version and free version are different. But...Actually, I'm trying to figure out the differences between the rainfall values shown on the 'Rain & Thunder' layers and basic weather forecast on the same place. I just found they aren't exact the same value, especially for heavier rainfall cases, so I have no idea which one is correct. I guess it might be caused by the different definition of accumulated time period or the interpolation between each grid point.

@korina Thanks! So the value in Meteogram is the precipitation accumulated over a quite different time period compared to the Rain & Thunder layer? What's the time period you'd applied to do the calculation?

And I'd like to know whether the value of 'rain' in Meteogram & Airgram represents the large-scale precipitation or not? According to the description of parameter on ECMWF's website, total precipitation is the sum of large-scale & convective precipitation. It seems that the total amount of precipitation has been split into two parts in the bar graph in Meteogram: the large-scale term and convective term. Furthermore, the sum of 'Rain' and 'Covective' is exact the value in basic list, which might indicates the total precipitation. As a result, the term 'Rain' might be interpreted as the large-scale precipitation part in Meteogram.

Hi, I've just found that the values of the 'last 3 hours' precipitation are different in the Meteogram and the layer data. For example, in this picture (https://imgur.com/k0uKcEq), the value derived from the weather picker is 71mm, but the value from the basic Meteogram on the same point is 92mm, which one is correct? Is it resulted from the different definition of the two rainfall value?

Another question is, the value of 'Rain' in Meteogram is 78mm, and the convective rainfall is 14mm. And the sum of them is equal to the value in the basic meteogram, 92mm. So the 'blue Rain' term is actually the 'large-scaled precipitation?' and the value 92mm is the total precipitation, the sum of large-scaled and convective precipitation, right?

Thank you!