Why the East Coast Has Been Spared This Hurricane Season
Hurricane Delta blasted onto Louisiana shores on Friday, October 9th, making it the 10th tropical storm to make landfall in the U.S. in 2020. That landing broke the record set in 1916, and forecasters don’t think we are done yet for the year.
Seven of the ten Atlantic storms that made landfall this year have done so on the Gulf shores. By comparison, the Atlantic Coast has been spared. Only one hurricane, Isaias, made landfall on the Eastern seaboard as a Category 1, with winds topping out at 85 mph by the time it reached the southern coast of North Carolina.
Wind and Water
Hurricanes tend to pick on a given region depending on wind currents in the North Atlantic and water temperatures in the Pacific. In the 1990s, North Carolina was targeted when El Nino reigned. In 2020, the Gulf region has been the focus.
Warm Gulf water temperatures have contributed to the severity of the storms, but the main drivers have been a persistent steering wind in the upper atmosphere that the storms have been riding in the North Atlantic and the cooler waters created by La Niña in the Pacific.
“La Niña can contribute to an increase in Atlantic hurricane activity by weakening the wind shear over the Caribbean Sea and tropical Atlantic Basin, enabling storms to develop and intensify,” according to Mike Halper with the National Oceanic and Atmospheric Administration (NOAA) Climate Prediction Center.
Meanwhile, clockwise winds around high-pressure centers typically steer storms from east to west in the open Atlantic and then north closer to the coastline. This year’s high-pressure system has moved the storms in a more westward direction, pushing them into the Gulf.
Storms are Intensifying
To make matters worse, a 40-year study of satellite data of global storms by NOAA and the University of Wisconsin shows that while global warming isn’t causing more storms, it is making them more severe.
“The change is about 8% per decade. In other words, during its lifetime, a hurricane is 8% more likely to be a major hurricane in this decade compared to the last decade,” says Jim Kossin, author of the study.
Associated Costs for All Americans
Hurricanes are relatively small compared to winter storms that can span hundreds of miles. The compact size of hurricanes creates higher storm surges and stronger winds as a result, leading to costly damage and loss of life.
The government assumes most hurricane damage costs (FEMA), such as road and bridge repair, debris removal, and other infrastructure costs like levee and dune repair. Gilbert M. Gaul, author of The Geography of Risk: Epic Storms, Rising Seas, and the Cost of America’s Coasts, noted last year the “roughly 70% of FEMA’s hurricane disaster aid payouts since 1950 have been made in the last ten years.” In addition, the National Flood Insurance Program (NFIP) remains swamped in debt thanks primarily to hurricane-related flooding.
As of September 20th, NFIP’s debt rested at $20 billion (before Delta hit Louisianna), despite a move by Congress in 2017 that “canceled” $16 billion in debt, transferring the responsibility to taxpayers.
The 2020 hurricane season doesn’t end until November, and experts predict another 2 or 3 storms this Fall. If they occur, we can expect to see more of the same with excessive rain and flooding, higher storm surge, rapid strengthening, and probable Gulf Coast landfall.
Sources: The Philadelphia Inquirer | USA Today | CNN | NOAA