Warm ocean water and a weak west-to-east flow across the southern United States will translate into a busier-than-average hurricane season this year in the Atlantic and Caribbean basin.
While forecasters disagree on the number of named tropical systems will form, they agree that the total will be a bit more than usual.
And forecasters are reminding inland residents of the Carolinas tropical systems often trigger tornadoes and severe flooding hundreds of miles from coastlines.
The 2017 Atlantic hurricane season began Thursday and continues through Nov. 30, but the year’s first named storm, Arlene, actually formed in April. Meteorologists say the period from mid-August into early October is usually the busiest time for tropical systems.
Forecasters at the National Weather Service in Greer note that inland locations like the Rock Hill area can suffer from tropical systems.
In 2004, a dying Hurricane Frances made landfall on Florida’s east coast and then triggered dozens of tornadoes as it moved north through South Carolina. And the worst flooding in Matthew last year happens well inland, in the sandhills of the Carolinas.
“In the last 30 years, inland flooding has been responsible for over half the deaths associated with tropical cyclones in the United States,” the National Hurricane Center’s Ed Rappaport said.
The National Hurricane Center is predicting between 11 and 17 named storms, with sustained winds of 39 mph or stronger; five to nine hurricanes, with winds of 74 mph of more; and two to four major hurricanes, with winds of 111 mph or stronger.
The annual averages are 12 named storms, six hurricanes and three major hurricanes.
Last year was the busiest since 2012, with 15 named storms, seven hurricanes, and four major hurricanes. The total included Hurricane Matthew, killed more than two dozen people and caused more than $2 billion damage in the Carolinas last October.
Two other highly regarded tropical weather forecasters have produced similar predictions for 2017.
Phil Klotzbach, of Colorado State University, said Thursday that his team expects 14 named storms, six hurricanes, and two major hurricanes this year. Klotzbach also said there is a 25.4 percent chance of a tropical storm or hurricane making landfall this year in South Carolina.
Meanwhile, North Carolina State’s Lian Xie is predicting 11 to 15 named storms, four to six hurricanes, and one to three major hurricanes.
Robert Fenton Jr., acting FEMA administrator, said that while forecasting the number of storms is helpful in planning, “It only takes one to disrupt our lives.”
Meteorologists agree that water temperatures in the tropical Atlantic Ocean are warmer than usual this year, a condition that helps tropical weather systems develop. And the west-to-east flow across the southern United States is expected to be weak this year. When the flow is strong – during so-called El Nino episodes – the upper-level winds tend to disrupt the formation of hurricanes.
Klotzbach said conditions this year resemble 1957, 1969, 1979 and 2006. Three of those years had slightly-below-average number of tropical systems, but 1969 was among the busiest in decades. The 1979 season included Hurricane David, which made landfall south of Charleston. And the 2006 season included Tropical Storm Alberto and Hurricane Ernesto, each of which caused severe flooding in North Carolina.