J. Climate http://doi.org/j7q (2013)

The intensity of tropical cyclones is projected to increase over the coming century. Model simulations in the North Atlantic suggest that the tracks of tropical cyclones are also set to shift.

Angela Colbert of the Rosenstiel School of Marine and Atmospheric Science, University of Miami, and colleagues assessed the impact of a rise in greenhouse gas concentrations over the twenty-first century on tropical cyclone tracks in the North Atlantic, using climate model simulations and a hurricane track model. The frequency of straight-moving cyclones — which tend to hit the Caribbean coast and the Gulf of Mexico — is projected to decline by 5.5%. In contrast, the frequency of cyclones that re-curve into the open Atlantic Ocean and avoid the US coast is projected to grow. As a result, the tropical storm count is projected to fall by 1–1.5 tropical cyclones per decade over the southern Gulf of Mexico, the Caribbean and Central America. The mid-Atlantic storm count is projected to rise by the same amount.

The researchers suggest that an eastward shift of locations where the cyclones form, together with a weakening of the subtropical easterly winds, is responsible for the change in curvature of tropical storm tracks.