Government Agencies

Met Office: World Weather
Provides locational forecasts, seasonal forecasts, cyclone and tropical storm forecasts, weather from locations round the world, satellite imagery and information on the world climate.
http://www.metoffice.gov.uk/weather/world/

World Meteorological Organization (WMO)
UN weather agency provides official news, forecasts and warnings plus major issues, hot topics, publications, meetings and membership list. Based in Geneva, Switzerland. [Arabic, English, French, Spanish]
http://www.wmo.ch/