True - but if we want to hijack the thread onto what is actually useful....
Then as stated: TAFs, F214 & F215 for same day forecast, and for longer range the Met Office charts - available on avbrief and here:
http://www.greatweather.co.uk/
No need to register (3/4 down page under Forecast Charts then click on T+xx ... from G Mueller (not MetO?))
These are also worth studying over time so that you can see how reliable (or not) they are and convert what they are saying into reality. They are my source for working out ahead of the game whether a longer trip may or may not be on.
(and before anyone says it I obviously use the TAFs and Fs on the day)
Its also interesting to see how much a forecast chart for 5 days away can change.
Are there any other worthwhile sources?