@idefix37 said in Why same model (ECMWF) differ in other sites/apps:

@Dimitar-Mihaylov
Yes, but you must know that the weather model calculations are all based on air pressure levels, not on real elevation.
However it would be useful to display the average elevation corresponding to these pressure levels. As it is displayed just below for clouds but not very detailed:

Or you need to make your own pressure / averaged elevation scale yourself.

I understand and know that most of the calculations are based on the air pressure levels but that doesn't change the fact it's not convenient for the normal user.

This is exactly every application's "you had one job" thing - to process the information and present it in a understandable way.

If I wanted to do my own calculations with the raw data then I would not use any app at all.

Anyway - that was just a suggestion for improving the UI.

@idefix37 said in Why same model (ECMWF) differ in other sites/apps:

@Dimitar-Mihaylov
What you call the “forecast grid” is probably the Basic meteogram called Basic in Windy. For the freezing level you just need to switch on Airgram, as @Filip_K said.
I don’t know if a customisable meteogram could be made. Probably not easy.

I checked the Airgram but as mentioned before - the reference axis for the freezing level is air pressure not altitude which is not useful, at least not for me.

Yes, that's what I thought. It's not really useful in that configuration but hopefully it will get added in the forecast grid.

I completely agree with the above mentioned.

The forecast grid should be customizable with the parameters every user needs.

I need the freezing level, wind chill etc but I can only see them through the interactive map but not just written in the grid for the spot I need.

@Filip_K said in Why same model (ECMWF) differ in other sites/apps:

Hi @Dimitar-Mihaylov, already available: https://www.windy.com/-Show---add-more-layers/overlays?deg0,48.546,31.399,5

Oh, great.

Can I add it into the "forecast window" with the wind/temp/snow/rain/etc or I can see it only on the map when I move it around? Because when I choose one of my saved favourite spots the freezing level is not shown.

Thanks again.

Well, okay, so we can assume the windy.com forecast should be more accurate.

Would've been great if I could stay at a mountain hut and just make a prospective trail comparing the two forecasts :)

Anyhow.

One more question which is offtopic - as I can see few of you are developers/moderators - do you consider adding a "freezing level" line as in the windy.app interface? That feature I must say is really handy. Thanks.

Alright, let's try again. Here are two screenshots - windy.app and windy.com showing absolutely the same spot at the same time. One of the forecasts has been updated almost 1 hr ago, and the other one - almost 4hrs ago, hence 3hrs difference (but I must say that there was the same pattern of discrepancy between the two even when the update times were in favour of the other app.)

As you may see: Per windy.app the calculated snowfall is almost TRIPLE as much as per windy.com.

Something is just not right - I cannot wrap my head around how the same forecast model has that much of discrepancy between two different apps. The 3hrs difference in the update time cannot be a legitimate reason. If a forecast model cannot predict the weather for the SAME day why does it exist at all?

I am completely aware that windy.com and .app are different things. That's why I am comparing them.

I check and compare them throughout the day a few times. And not on one occasion as well. For different spots as well.

The reference time is almost exactly the same - about an hour difference. The model in windy.app is 14km resolutions as per their site. I don't think that's so great of a difference.

Anyway, it's just frustrating. I am mainly a winter user and the main objective is temp, snow, wind. I just wanted to know where the difference in snow accumulation comes from, because if one of the sites was saying snow 1,00m and the other 1,10m - that's fine, 10% difference not big deal. But between 10cm and 0cm it's quite the opposite. Anyhow, it is what it is.

I need an explanation:

Comparing two sites (windy.com and windy.app) for the forecast of absolutely the same spot in the mountain using absolutely the same model - ECMFW, there is great difference in the temperature, snow accumulation etc.

Windy.com says there would be 0.1cm of snow accumulation but windy.app says there will be 9cm. The temperature differ from -10C (windy.app) to -5C (windy.com).

I am talking about a forecast for the same day. Not 6 days from now.
Using the premium version of both sites and once again - the same model!

Thanks.

Well, okay, I understand but I have to say it is a bit misleading because the word "resolution" is used when explaining the difference between the forecast models and the advantages between 30-20km and 7-9km model. On the other hand it is used as an "images resolution" hence - the confusion.
Anyway.

Another question - if the model resolution is predetermined by itself why some apps use GFS 27 and yours use GFS 22? Where the difference come from?

Thanks.