Problem with the UK met office, and the BBC forecasts they provide the public with is that they are all a bit vague and dumbed down. Really annoying since we pay the vast bulk of their running costs with taxes and licence fees. Some of us can cope with numbers.
A couple of alternatives:
http://www.yr.no/ is the Norwegian weather service (in English too) with hour by hour forecasts, expected rainfall range and useful graphs. When the met office and the Norwegians have differed, it's usually the Norwegians who get it right. There's also an Android widget called AIX that draws a 24 hour forecast on the phone homepage using yr.no data.
http://xcweather.co.uk provides a lot of detail, 3 hour forecasts intervals etc. Not as slick but it works.