Forecast period representing the wind gust value in ECMWF meteogram

idefix37

@stitch
In the FAQ it is said to be during the last 3 hours.
https://community.windy.com/topic/3361/description-of-weather-overlays?sort=oldest_to_newest

Gkikas LGPZ

@idefix37
FAQ was written years ago when windy provided only 3hr forecast data.
Now, we have 1hr time resolution so clarification needed.

idefix37

@Gkikas-LGPZ
Yes, same with rainfall which is said to have occurred in the last 3 hours. This is confusing in the 1-hour meteograms.

idefix37

@Suty
Please could you clarify the question about the wind speed, gusts speed and rain amounts in the 1-hour meteograms. Are they predicted for the last 3 hours or for the last hour?
It seems that for rain it is quite obvious: forecast for the last 3 hours on the weather picker and 1 hour in the 1-hour meteogram.

Is it the same for wind and gusts?

Suty

@idefix37 Hi there, as you said rain in the picker is displayed as a sum of 3 hours, but beteogram in general shows all values in 1h step and it is not anyhow interpolated from 3 hours.

stitch

@Suty

Are the meteogram images generated in-house or are they sourced through ECMWF or another party? If in-house, are you able to seek which ECMWF gust field code is used for the Meteogram display?

From the ECMWF HiRes 10-day dataset:
10fg6 (10m gust in last 6hrs),
10g (10m gust in since previous post-processing),
10fg3 (10m gust in last 3hrs),
and i10g (instantaneous 10m gust).

There are a few options available. I use the EC gust as a forecasting parameter and would like to get confirmation as to the gust sampling time.

Thanks.

Filip_K

Hi @stitch, we're using 10fg3 for forecast hours 0-144 and 10fg6 from forecast hour 150 further. That is how these parameters are available. Values for 1h step are linear interpolation of those 3h or 6h values.

idefix37

@Filip_K
Hi,
For Wind, are 1 hour step forecasts also interpolated ?
But not for Rain?

stitch

@Filip_K thank you

Filip_K

@idefix37

For Wind, are 1 hour step forecasts also interpolated ?
But not for Rain?

For ECMWF-HRES, only gusts need to be interpolated because they are available only every 3 or 6 hours. Precipitation is available every hour.

idefix37

@Filip_K
Thanks you, and same for Wind, ECMWF provide hourly forecasts ?

Filip_K

@idefix37
yes, every other parameter is available for each hour