Here are some of the links that I use to get weather information for hot air ballooning in the U.K.

BBC Online - Weather Centre.  http://www.bbc.co.uk/weather/

BBC Online - Weather Centre - UK Radar.  http://www.bbc.co.uk/weather/uk_radar.shtml

BBC Online - Weather Centre - UK Satellite.  http://www.bbc.co.uk/weather/satellite.shtml

- Flight briefing services for pilots.  http://www.avbrief.com/

Tom Dawes-Gamble - Airport Information and Weather.  http://www.tmdg.co.uk/weather/

- European Centre for Medium-Range Weather Forecasts.  http://www.ecmwf.int/

Alexander L. van Homoed - European Aviation Weather Center.  http://www.phd.nl/aviation/wx/

- Aeronautical information for pre-flight planning.  http://www.ais.org.uk/