Forecasters say Fiona faces two main obstacles that could spell its eventual demise and the tropical storm is no threat to land.
Tropical Storm Fiona, the sixth named storm of the Atlantic hurricane season, is a bit more organized today but, faces a more hostile atmosphere in the days ahead in the central Atlantic Ocean.
As of Thursday morning, Fiona’s convective presentation on infrared satellite imagery looked the part of a tropical storm, with a central area of thunderstorms and some banding evident especially north of the center, which was about halfway between the Lesser Antilles and the coast of western Africa.
Although some short-term strengthening is expected, it faces a familiar pair of nemeses headed into the weekend.
First, Fiona is expected to face increased wind shear, namely, differing winds aloft compared to near the surface. Wind shear tends to displace a tropical cyclone’s convection from its center of circulation and can also tilt that circulation. While some intense hurricanes can fend off some light to moderate wind shear, weaker systems can be ripped apart if the shear is too strong.
The increased southwest winds aloft responsible for the anticipated wind shear, along with a fairly weak Bermuda-Azores high will also cause Fiona to gain too much latitude to ever be a threat to the Lesser Antilles.
Dry air in the central Atlantic is also expected to wrap into Fiona’s circulation, encouraging stronger thunderstorm downdrafts and dispersing the convection from the system’s center.
Therefore, it is possible Fiona, weakened by wind shear and dry air, could degenerate into a remnant low or tropical wave. Continue reading