SAWS: http://www.weathersa.co.za/References/MetTermsGlossary.jsp#p
Australian Bureau of Meteorology: http://www.bom.gov.au/lam/glossary/apagegl.shtml
American Meteorological Society (AMS) (with search function, very good link): http://amsglossary.allenpress.com/glossary/browse?s=A&p=1
Description of the variables
For SAWS variable description: http://www.weathersa.co.za/References/FCTerms.jsp
For CSAG variable description: http://www.myweather.co.za/weatherinfo/Forecast.html