How does Windy.com deal with the transition from 00Z -> 06Z IFS model runs?
-
This also applies to 12Z -> 18Z runs.
The ECMWF IFS model runs are "full runs" at 12Z and 00Z, but for 06Z and 18Z the model only runs out to +90hr.
Premium users can see these "limited runs" (18Z and 06Z), and the information panel will tell you when it is showing those runs. However, since they only go to +90hr, there must be an interpolated step after +90hr when it transitions into showing data from last full run.
How is this done smoothly in windy.com, is there a gradual blending across timesteps? Or does it just jump from the 18Z run to the 12Z run? There are situations where you could see quite a huge jump, but I haven't come across one yet.Also: the information panel should tell you that you are not looking at an 18Z/06Z run once you have gone beyond +90hr. At the moment, it claims that it is showing you the 18Z/06Z (if that is the newest run), and that is only true for the first 4 days.
-
@Jon-T-3
Parameters forecasts are not smoothed between a time step and the next one. The model provides a prediction hour by hour and Windy displays the forecast hour by hour too. Interpolation and smoothing is only between grid points. -
@idefix37 Thanks for the clarification. It would probably be good if the information panel for 18Z and 06Z runs could tell the user that after +90hr, it is actually the 12Z/00Z run data.
-
@Jon-T-3
See the detailed schedule of the HRES model dissemination (HRES is the version of the ECMWF model used by Windy).
https://confluence.ecmwf.int/plugins/servlet/mobile?contentId=272310483#content/view/272310483You see that up to 90h you get 1h steps. From 93h you get 3h steps. So only the 1h steps are updated with 06Z and 18Z runs.
I must admit that this limit is not obvious, but I doubt that many users would take it into account.
