A new model simulation of Atlantic hurricane activity, which projects the last two decades of this century, predicts fewer hurricanes overall, but a slight increase in intensity for hurricanes that do occur. The NOAA report said hurricanes are also projected to have more intense rainfall, on average, in the future.

These findings are reported in a study by scientists at the agency's Geophysical Fluid Dynamics Laboratory in Princeton, N.J., which was published online this weekend.

"This study adds more support to the consensus finding of the Intergovernmental Panel on Climate Change and other reports that it is likely that hurricanes will gradually become more intense as the climate continues to warm," said Tom Knutson, research meteorologist and lead author of the report. "It's a bit of a mixed picture in the Atlantic, because we're projecting fewer hurricanes overall.”

According to an agency release, the scientists performed hurricane simulations using a new regional model that offers both higher resolution and an improved ability to simulate past observed changes in Atlantic hurricane activity. In a preliminary study published last October in the Bulletin of the American Meteorological Society, the new model was shown to successfully reproduce Atlantic hurricane counts year-by-year from 1980 to 2006, including the observed increasing trend.

In the new study, said the release, the model was used to test the influence of greenhouse gas warming on Atlantic hurricane activity through the end of the 21st century. Simulations revealed higher levels of wind shear and other changes, which act to reduce the overall number of hurricanes in the model.

Visit http://www.gfdl.noaa.gov/research/climate/highlights.