When ξ = 0, the GEV becomes a Gumbel distribution and the tails are "light" as is the case for the normal and log-normal distributions.
When ξ > 0, the GEV becomes a Frechet distribution and the tails are "heavy" as is the case for the t-distribution and the Pareto distribution.
When ξ < 0, the GEV becomes a Weibull distribution and the tails are "lighter" than a normal distribution.
