Hurricanes that intensify rapidly — a characteristic of almost all powerful hurricanes — do so more strongly and quickly now than they did 30 years ago, according to a study published recently in Geophysical Research Letters, a journal of the American Geophysical Union.

While many factors are at play, the chief driver is a natural phenomenon that affects the temperature of the waters in the Atlantic where hurricanes are powering up, according to scientists at the U.S. Department of Energy's Pacific Northwest National Laboratory and the National Oceanic and Atmospheric Administration.

They found that a climate cycle known as the Atlantic Multidecadal Oscillation or AMO is central to the increasing intensification of hurricanes, broadly affecting conditions like sea temperature that are known to influence hurricanes.

Last year's lineup of powerful storms — Harvey, Irma, Jose and Maria — spurred the scientists to take a close look at the rapid intensification process. This occurs when the maximum wind speed in a hurricane goes up by at least 25 knots (28.8 miles per hour) within a 24-hour period. It's a rite of passage for nearly all major hurricanes, including the big four of 2017.

 

Continue reading at Pacific Northwest National Laboratory.

Image via Pacific Northwest National Laboratory.