In 2017, Hurricane Harvey moved very slowly across parts of Texas (USA) dropping “more than 30 inches of rain in two days and nearly 50 inches over four days.” “Harvey’s rainfall exceeded every known flooding event in American history since 1899.”
The reason for the high rainfall totals was the slow movement of the storm–and a 2018 study reports that “between 1949 and 2016, tropical cyclone translation speeds (how quickly a storm moves) declined 10 percent worldwide.”
While a 10% change may not seem significant, the reality of Hurricane Harvey and other recent storms show the effect–“devastating flooding and billions of dollars of damage” as well as death, trauma, stress, widespread and long-lasting environmental damage, and the list goes on.
What is the cause of the slower storm movement? “Broader evidence suggests that climate change is playing a role.”
The winds that push hurricanes along are influenced by temperature differences between the tropics and the Poles. That temperature difference is getting smaller. As a result, the steering winds are weakening, and the hurricanes and other storms are moving more slowly dropping more rain and causing more destruction.
Hurricanes are becoming more dangerous. Additional scientific analysis indicates that as the winds that push hurricanes weaken, the winds inside hurricanes strengthen.
And, the danger from hurricanes is not just along the coasts. Inland flooding and mudslides caused by the intense rainfall “poses the highest mortality risk nowadays in certain regions.”
Read the article (Kendra Pierre-Louis, New York Times, June 6, 2018).