The Tropical-like Cyclone “Ianos” in September 2020

Fabio Zimbo,Daniele Ingemi,Guido Guidi

doi:10.3390/meteorology1010004

Abstract

In this paper, we analyze a Mediterranean TLC (tropical-like cyclone) which occurred between 15 and 20 September 2020 called “Ianos”. First, the paper briefly presents the “medicane” phenomenon; then, it analyzes the synoptic situation that produced Ianos initiation and development, as well as its intensity (minimum pressure, wind speed) and trajectory. A comparison with similar past events is also provided. Furthermore, we analyze its lightning activity, rainfall data from some meteorological stations of the areas most affected by Ianos, such as Calabria and the Ionian islands of Greece, and the hydrogeological and hydraulic instability effects caused by the passage of the TLC on these territories.

Highlights

Medicanes, known as tropical-like cyclones (TLCs), are mesoscale eddies with hybrid characteristics between extratropical and tropical cyclones [1,2] occurring in the Mediterranean basin [3,4,5,6]
The atmospheric patterns in the Mediterranean initially present prevailing typical baroclinic characteristics; medicanes mainly stem from extratropical cyclones associated with a large trough of the polar flow
The latter, extending and elongating toward southern latitudes, develops in upper-level lows isolated from the main flow itself

Summary

Introduction

Medicanes (portmanteau for Mediterranean Hurricanes), known as tropical-like cyclones (TLCs), are mesoscale eddies with hybrid characteristics between extratropical and tropical cyclones [1,2] occurring in the Mediterranean basin [3,4,5,6]. According to some recent studies [19,21], climate change projections would lead to a slight decrease in the frequency of medicanes in the Mediterranean (as well as of tropical cyclones) in the future, but the strongest ones would become even more intense. Studying these events would assume even greater significance because of their potential to cause widespread hydrogeological and hydraulic instability, with loss of human life and significant infrastructural and economic damage to the affected areas, especially islands and coastal zones.

Tropical like Cyclone “Ianos”

Dynamic Analysis