Meehl et al. (2000)
Also: Meehl et al. 2000
Trends in extreme weather and climate events: Issues related to modeling extremes in projections of future climate change
Meehl, G. A., Zwiers, F., Evans, J., Knutson, T., Mearns, L., & Whetton, P. (2000). Trends in extreme weather and climate events: Issues related to modeling extremes in projections of future climate change*. Bulletin of the American Meteorological Society, 81(3), 427-436. Link to PDF
References
All IPCC definitions taken from Climate Change 2007: The Physical Science Basis. Working Group I Contribution to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change, Annex I, Glossary, pp. 941-954. Cambridge University Press.