Organizing committee: Peter Guttorp (Department of Statistics, University of Washington), Phillippe Naveau (Centre National de la Recherche Scientifique, Laboratoire des Sciences du Climat et l’Environnement) and Francis Zwiers (University of Victoria)

It is worth taking a few lines to think about the terminology that is used to describe extremes in climate science and hydrology. Considerable confusion results from the various definitions of extremes that are in use. Part of this confusion occurs because the word extreme can be used to describe either a characteristic of a climate variable or that of an impact. In this workshop, we will not cover impacts (e.g., the effect of tropical cyclones on infrastructure). Even so, the lack of precise language hinders advances in research on extremes because it makes the job of clearly articulating hypotheses and objects for analysis all the more difficult. Therefore, it would be of interest to spark discussions among participants in order to propose mathematically coherent definitions of extremes, especially in a non-stationary context (Katz and Rootzén, 2013).