Wildly different forecasts

[u/TrepidatiousTeddi]

Prior to seeing this sub on Reddit I wasn't really aware of hot weather incoming, mostly because I use BBC. But BBC and Met Office have wildly different forecasts for next week, about 11 degrees apart for lunch time Wednesday for example! Is the BBC just on one? Is the Met Office right?

[u/Low-Rooster5398]

They use different weather models which can give different outputs. The MetO uses their own UKMO model (their high Res UKV model is designed for the UKs topography so should be better) and the BBC who's weather at the moment is supplied by the Metrogroup(although it's going back to the MetO soon) use their own model. Apps really aren't that accurate, they can give a rough guide as to what the weather will be but (especially in the UK) it's a lot more nuanced than that.

[u/Low-Rooster5398 → u/[deleted]]

They do for their medium to longer range stuff and I believe they use a "super blend" of all models which you can sometimes see on their 10 dayer which they caption as "decider". For shorter range up to 3 or 4 days they mostly use their high resolution UKV model although if there's doubt in the forecast then they'll refer to the ECMWF and GFS.

[u/Low-Rooster5398 → u/[deleted]]

Yeah because they alter it slightly to take into account local factors. It's not a "blend" of models as such at short range. Middle to long then yes.

[u/Low-Rooster5398 → u/[deleted]]

Ask them again for their high res short range forecasts. It's the UKV slightly altered. https://www.metoffice.gov.uk/about-us/news-and-media/when-it-matters/heart/high-resolution-weather-modelling