[PinkTequila]

May I point out that you've left off the Met Office, from where these others derive their forecasts?

I don't think they should just come under "Other"!

Actually they don't all use the metoffice to make their forecasts, most analyze the numerical models from the ECM or GFS and make their own forecast either by computer or by human intervention. The BBC weather site just uses the GFS computer prediction hence its inaccuracy as does Metcheck. Netweather is supposedly more accurate certainly in the short term. The met Office I think are most accurate in their two weekly forecast but often don't add detail so less to get wrong.