mynthdd2 wrote:......am assuming MWIS gets the basics from the Met Office then tweaks a few extras in eg effect of altitude etc as for example Met Office ‘wind chill’ is defined at a 2m height?
MWIS likely uses other model data as well at the Met Office (for example the US-based GFS model, whose output is all freely available, unlike the Met Office). There is quite a lot more to it than just taking a low-level forecast and adjusting for altitude, especially for cloud bases. There are ruls of thumb
I'm surprised that it's not universally known that the Met Office issue a mountain specific forecast -https://www.metoffice.gov.uk/weather/specialist-forecasts/mountain - I guess it's not that easy to find by browsing their website, and it's not available on their phone app.
What sets the MWIS and Met Office mountain weather forecasts apart from anything else is that a human forecaster is involved, and not just an algorithm.