Hurricane Helene, the most lethal tropical cyclone in the continental United States in nearly two decades, is also among the country’s most costly natural disasters. These are just a couple of the key findings outlined in the recently published final report by the National Hurricane Center. Spanning over 100 pages, the report, released on Wednesday, provides a comprehensive analysis of Helene’s development in the Caribbean Sea on September 24 to its dissipation over Tennessee four days later. Here are some of the notable revelations from the report:
Deadliest Hurricane in the U.S. Since Katrina:
According to data gathered from various government and media accounts, at least 175 fatalities were recorded in the U.S. as a result of Helene’s destructive flooding, powerful winds, storm surges, and tornadoes. Additionally, an additional 70 individuals lost their lives in the aftermath of the storm, due to incidents such as vehicle accidents, medical emergencies, and accidents during cleanup operations. The overall death toll of at least 248 makes it the highest among mainland U.S. tropical cyclones since Hurricane Katrina in 2005.
Impact of Flooding and Winds:
Out of the 175 deaths during Helene, 94 were linked to flash floods caused by heavy rainfall, including floods triggered by landslides and debris flows. This proportion of fatalities due to flooding rain aligns with recent findings by the NHC regarding U.S. hurricane-related deaths since 2013. Furthermore, a striking 65 deaths were attributed to the storm’s winds, with 61 of those fatalities resulting from falling trees, highlighting the danger posed by high winds not only during hurricanes but also in other severe weather events.
Economic Impact:
Helene ranks as the seventh costliest hurricane in U.S. history, causing an estimated $78.7 billion in damages, according to estimates from NOAA’s National Centers for Environmental Information. This places it above hurricanes like Ivan in 2004, Rita in 2005, and Wilma in 2005 in terms of economic losses.
Record Rainfall and Devastating Flooding:
Southern Appalachians experienced up to 30 inches of rain, leading to widespread flooding and landslides. The National Weather Service issued 34 flash flood emergencies during the event, signalling a severe threat to life and property. Numerous stream and river gauges recorded historic crests during Helene, with rivers like the French Broad and Swannanoa surpassing century-old records.
In summary, Hurricane Helene stands out as a catastrophic event with significant implications for both human life and economic infrastructure in the United States.
During Hurricane Helene, there were 2,015 landslides in the southern Appalachians, mainly in western North Carolina. Half of these slides affected buildings, roads, or rivers. The storm caused widespread power outages, affecting around 7.4 million customers in the Southeast. Helene’s strong winds, combined with its rapid movement and the saturated ground from heavy rain, led to significant damage. Wind gusts reached up to 106 mph on North Carolina’s Mt. Mitchell, 100 mph in Alma, Georgia, and 99 mph in Perry, Florida.
Helene also generated a storm surge of 12 to 16 feet in areas like Keaton Beach and Steinhatchee, causing extensive destruction to buildings. Cedar Key experienced record-breaking inundation of 9.3 feet, resulting in significant damage to homes. The storm surge impacted the Tampa-St. Petersburg metro area as well, with water levels reaching 6.5 to 7.3 feet.
The storm was responsible for fourteen deaths due to storm surge. Helene also spawned 39 tornadoes, including an EF3 tornado in Rocky Mount, North Carolina, and an EF1 tornado in Cordova, South Carolina. The Rocky Mount tornado, though brief, was rare in its intensity, while the Cordova tornado stood out for its size, measuring 1,100 yards wide.
Jonathan Erdman, a senior meteorologist, has been reporting on extreme weather events since 1996.
