Statistical modeling of hot spells and heat waves

To address this shortcoming, we extend the point process approach to extreme value analysis to model the frequency, duration, and intensity of hot spells. The annual frequency of hot spells is modeled by a Poisson distribution, their length by a geometric distribution.

To account for the temporal dependence of daily maximum temperatures within a hot spell, the excesses over a high threshold are modeled by a conditional generalized Pareto distribution, whose scale parameter depends on the excess on the previous day. Requiring only univariate extreme value theory, our proposed approach is simple enough to be readily generalized to incorporate trends in hot spell characteristics. Through a heat wave simulator, the statistical modeling of hots spells can be extended to apply to more full-fledged heat waves, which are difficult to be modeled directly.