An investigation of the pineapple express phenomenon via bivariate extreme value theory

We study regional climate models' ability to reproduce these events by defining a quantity that captures the spatial extent and intensity of PE events. We use bivariate extreme value theory to model the tail dependence of this quantity as seen in observational data and the Weather Research and Forecasting (WRF) regional climate model driven by reanalysis, and we find tail dependence between the two.

To link to synoptic-scale processes, we use daily mean sea-level pressure fields from the reanalysis product to develop a daily "PE index" for extreme precipitation that exhibits tail dependence with our observational quantity. Other models from the North American Regional Climate Change Assessment Program ensemble are used to estimate the future marginal distributions of reanalysis-driven WRF output and observational precipitation.