Current Conditions

Bramblemet - roughly equidistant from Cowes, Calshot and Hill Head.
Christchurch, Hurst Castle, Lymington, Portland, Yarmouth.
Poole Harbour Weather
Bell Hill Weather station - Actual Wind/Temp/Pressure. [Web Cam]
Whitesheet Weather station - Actual Wind/Temp/Pressure. [Web Cam]
Henstridge Airfield weather station which gives up-to-the minute accurate weather reports 24/7. It is 8 miles NW of Bell and slightly less SW of Mere, so useful for both sites.
Durlston Weather - Useful for Ballard/Knitson.
Sat24 - (almost) live satellite pictures of UK.
Skylinkweather - 100 UK locations.
Strategic Regional Coastal Monitoring Programmes - south coast stations.
Wendy Windblows - telephone into automated weather stations (paid subscription).
XC Weather - Actual Wind/Temp/Pressure/Weather.
"Windy" UK Weather - Actual Wind/Temp/Pressure/Weather.

Live Webcams

Swanage webcam - controllable web cam you can zoom on Ballard take-off. log in is guest, pswd guest
Ballard Down
Highcliffe Sailing Club
Mudeford Quay Bay
Bournemouth/Boscombe Beach Webcams
Bournemouth Pier View Webcam
Weymouth
Dorset Webcams

Forecasts

Technical
ECMWF - synoptic charts +3-6 days
RASP - Regional Atmospheric Soaring Prediction: thermal strength, cloudbase, soundings, etc.
Simplified RASP + Synoptic Chart - Tailored for Paragliding.

Local
Met Office SW forcast
Blandford - for Bell Hill
Bournemouth - for Southbourne
Christchurch - for Barton
Dorchester - for Cowdown / Telegraph(Batcombe) / Eggerdon
Lasham Gliding Society - nr Alton, Hants (email subscription)
Shaftesbury - for Monk's Down / Winklebury / Whitsheet
Swanage - for Ballards / Knitson / Kimmeridge
Weymouth - for White Horse / Ringstead

General
Accuweather - a selection of UK cities
BBC UK Weather - wind and synoptics avalable
hgpg.co.uk - a collection of weather links
Meteorologica
Netweather GFS and other charts
Oceanweather
Ten day temperature outlook for Europe
Ten day precipitation outlook for Europe
Windguru - coastal weather, Kimmeridge Bay selected

Satellite