Influence of Storm–Storm and Storm–Environment Interactions on
Tropical Cyclone Formation and Evolution
This page includes the abstract and a link to my Master's Thesis that was published in the Monthly Weather Review Journal.
HURDAT positions and storm classification for TCs Danielle, Earl, Fiona, and Gaston. The 0000 UTC positions are marked by
a black-filled circle, and classifications are colored according to the key inset in the bottom left. (right inset) Time–longitude diagram of 700-hPa meridional wind (shaded in m s^-1) averaged in the 108–208N latitude band. Cyclonic horizontal shear couplets corresponding to Danielle (D), Earl (E), Fiona (F), and Gaston (G) are indicated. The west coast of Africa is marked by a solid black line.
Abstract
The aim of this study is to examine the development of four tropical cyclones (TCs) in the North Atlantic basin in late August and early September 2010. This period is of interest because four consecutive easterly waves emerged from West Africa and resulted in a multiple TC event (MTCE) over the North Atlantic. The first two TCs—Danielle and Earl—quickly developed into TCs east of 408W and eventually intensified into major hurricanes. Conversely, the last two TCs—Fiona and Gaston—developed more slowly reaching only weak tropical storm intensity at their peak. The close proximity and differing evolution of these four TCs provides a unique opportunity to examine how these TCs interacted with each other and their surrounding environment, which influenced their development as they moved westward across the North Atlantic. The results showed that concurrent extratropical cyclogenesis events over the western and eastern North Atlantic and the recurvature of TC Danielle produced increased meridional flow over the midlatitude North Atlantic. This increased meridional flow resulted in subsynoptic-scale regions of increased vertical wind shear in the subtropics, which delayed Earl’s development and led to Fiona’s demise. Additionally, increased meridional flow in midlatitudes contributed to anomalous drying of the subtropics. This dry air was entrained into Gaston’s circulation leading to reduced convection and weakening. These TC–TC and TC–environment interactions highlight the difficult challenge of forecasting TC genesis and position posed by MTCEs in a rapidly evolving synoptic-scale flow.
Fowler, J.P. and T.J. Galarneau, 2017: Influence of Storm–Storm and Storm–Environment Interactions on Tropical Cyclone Formation and Evolution. Mon. Wea. Rev., 145, 4855 – 4875, https://doi.org/10.1175/MWR-D-17-0131.1