HurricanesHuman-Caused Warming Cause More Slow-Moving Hurricanes

Published 27 April 2020

Hurricanes moving slowly over an area can cause more damage than faster-moving storms, because the longer a storm lingers, the more time it has to pound an area with storm winds and drop huge volumes of rain, leading to flooding. The extraordinary damage caused by storms like Dorian (2019), Florence (2018) and Harvey (2017) prompted researchers to wonder whether global climate change will make these slow-moving storms more common.

Hurricanes moving slowly over an area can cause more damage than faster-moving storms, because the longer a storm lingers, the more time it has to pound an area with storm winds and drop huge volumes of rain, leading to flooding. The extraordinary damage caused by storms like Dorian (2019), Florence (2018) and Harvey (2017) prompted Princeton’s Gan Zhang to wonder whether global climate change will make these slow-moving storms more common.

Zhang, a postdoctoral research associate in atmospheric and oceanic sciences, decided to tackle the question by using a large ensemble of climate simulations. He worked with an international team of researchers from the Geophysical Fluid Dynamics Laboratory on Princeton University’s Forrestal campus and the Meteorological Research Institute in Tsukuba, Japan. The results of this work was published in Science Advances.

Princeton says that Zhang and his colleagues selected six potential warming patterns for the global climate, then ran 15 different possible initial conditions on each of the six patterns, resulting in an ensemble of 90 possible futures. In all 90 simulations, they told the computers to assume that global carbon dioxide levels have quadrupled and the planet’s average temperature has risen by about 4 degrees Celsius — a level of warming that experts predict could be reached before the turn of the century, if no action is taken to curb fossil fuel use.

“Our simulations suggest that future anthropogenic warming could lead to a significant slowing of hurricane motion, particularly in some populated mid-latitude regions,” Zhang said. His team found about the storms’ forward motion would slow by about 2 miles per hour — about 10 to 20% of the current typical speeds — at latitudes near Japan and New York City.

“This is the first study we are aware of that combines physical interpretation and robust modeling evidence to show that future anthropogenic warming could lead to a significant slowing of hurricane motion,” he said.