Hurricanes Are Changing
There have been some strange hurricanes in the past few years. Some are causing an unusual amount of rain. Many have very fast winds. Hurricanes are becoming stranger because the climate is changing.
Hurricane winds are speeding up.
As the climate warms, the surface of the ocean warms, too. The warmer water changes hurricane winds.
A hurricane’s winds get stronger when it travels over warm ocean water and calm when it travels over cooler ocean water. (Play Hurricane Allie to explore how this works!) Because seawater is warming, the winds of hurricanes are getting stronger.
Hurricanes are making more rain.
Hurricane clouds are made of water that evaporates from the ocean. As climate changes and the ocean and air warm, more water vapor can get into the air. This means that the clouds of a hurricane can carry more water. And what goes up must come down as raindrops. Hurricanes that cause extreme rainfall are becoming more common as the climate warms.
Two U.S. Coast Guard officers boat through a neighborhood in Texas that flooded during Hurricane Harvey in August 2017. Between 40 and 60 inches of rain fell as Hurricane Harvey slowly passed through the Houston, Texas, area. The rainwater caused huge floods.
U.S. Coast Guard photo by Petty Officer 3rd Class Corinne Zilnicki
More wind and rain can cause more flooding.
The chance of floods caused by hurricanes increases as the climate warms.
Because climate change is causing more rain during hurricanes, floods caused by rain are getting more common, especially where the water can’t absorb into the ground.
Flooding can also happen on a coast when winds from a hurricane push ocean water towards the shore. This is called storm surge. Because climate change is causing stronger hurricane winds, this can cause more storm surge flooding. And because climate change is causing sea levels to rise, more places are in danger of flooding.