Inter-Decadal Shifts in Intense Extratropical Cyclones in the Northern Hemisphere

Abstract

Cyclones, both tropical and extratropical, have a large socioeconomic impact during any given year. Understanding the formation and evolution of these cyclones in the current climate therefore becomes imperative to minimize loss to property and life. Previous work by Kossin et al (2014) showed a significant poleward migration for the most intense tropical cyclones from 1982 to 2009. This sparks the interest in whether extratropical cyclones exhibit a similar trend within a changing climate. Data used stems from the European Centre for Medium-Range Weather Forecasts (ECMWF) ERA-Interim Analysis for an analogous time period from 1980-2015. Tracking and identification of cyclones is performed using the 850-mb level relative vorticity field with procedures similar to that used by Hodges (1995, 1996, 1999) and then limited to 30 degrees North latitude and higher. A statistically significant shift in the most intense cyclones, defined separately for minimal central pressure and vorticity maxima, from the Pacific Oceanic basin to the Atlantic Oceanic basin is found.