@gkikas-lgpz That may well be, but as an English speaker, and the language being used is English, the appropriate meaning of “basic” is “forming an essential foundation or starting point.” As Windy has the ECMWF model as it’s default, the impression of the description on the Windy forecasts is that the GFS is somehow inferior, simple, limited. In fact, in several ways, the GFS gives a more useful service to me as a sailor than ECMWF.

@idefix37 Ah! Perhaps it is cabin fever with a “summer” of being in harbour and seeing long spells when we have been unable to move. I now see my Windy problem. GRIB forecasts generally, PocketGrib, WeatherTrack, Weather4D, iGrib, PassageWeather, XyGrib, to name a few, all show clearly the base time for forecasts. It is always the first time for which output is available. With Windy.com, the first time for which output is shown is always midnight regardless of whether the base time is midnight or midday. Not being a habitual user of Windy, this had never really crossed my mind. Presumably, in the evening (c1900 UTC) upload, the information shown prior 1200 UTC is actual data. To be fair, Ventusky does something similar in that they show actual data for the past 7 days. In their case it is more obvious, to me, at least, and I automatically remember that the GFS updates at around 05, 11, 17, 23 UTC. ECMWF updates around 07 and 19 UTC but, not having the same operational commitments, may not be quite so reliable in times of updates. Windy predictions of update times seem overly cautious. Maybe, you should not be so specific in giving next update times. Maybe it is more of a caveat emptor, but it would be clearer if Windy only showed data from the T=0 times, ie for the 1200 UTC forecast, only show data after that time.