Category 1 hurricanes can cause damage comparable to higher categories due to their potential for flooding and dangerous storm surge.
When Hurricane Ernesto was classified as a Category 1 storm, it resulted in 40% of Puerto Rico losing power and triggered flash flooding. Scientists emphasize that lower-category storms can inflict damage similar to Category 5 hurricanes. Hurricanes are classified from Category 1 to Category 5 on the Saffir-Simpson scale, with Category 5 being the most intense. This classification system was developed in the 1970s by an engineer and meteorologist. Hurricanes are ranked based on sustained wind speed, but the Saffir-Simpson scale does not take into account other impacts such as storm surge and rainfall. Hurricanes of all sizes can bring both of these effects.
Category 1 hurricane Ernesto causes flash flooding and widespread power outages in Puerto Rico. (Photo: BBC).
“Focusing too much on hurricane classification can be misleading,” said Craig Fugate, former director of the Federal Emergency Management Agency (FEMA) and now a crisis response advisor. “While the winds of a Category 5 hurricane are undoubtedly destructive, the real danger lies in other characteristics of the storm. There is a significant risk when people underestimate the threat of a Category 1 hurricane due to its lower classification. Focusing on wind speed can lead to a false sense of security.”
A Category 1 hurricane like Ernesto can bring dangerous storm surges, devastating flooding, and tornadoes, resulting in infrastructure damage such as power outages, road blockages, and water contamination, along with various severe long-term impacts. In fact, the greatest threat to life comes from storm surge, caused by seawater being pushed onto land by the hurricane’s winds. Water levels can rise by at least 30 feet. A study found that 49% of hurricane-related fatalities in the U.S. are due to storm surge, 27% from flooding caused by heavy rainfall, while only 8% can be attributed to wind speed.
“The majority of damage comes from water, not wind“, stated Michael Wehner, a scientist at the Lawrence Berkeley National Laboratory who specializes in studying behavior changes during extreme weather events. “The problem is that the Saffir-Simpson scale simply measures the highest wind speed at any point during the hurricane.”
Moreover, experts are concerned about community safety when classifying hurricanes solely by wind speed. Category 3 hurricanes and above are considered major hurricanes by the National Weather Service, which means communities might perceive lower categories as not warranting concern. It is more important to consider the scale of the hurricane rather than just wind speed. A Category 1 hurricane can cause significant damage even with wind speeds below 95 mph. Hurricane Debby, a Category 1 storm, resulted in 5 fatalities with initial loss estimates ranging from $12.3 to $28 billion. Hurricane Sandy was also classified as a Category 1 storm and is the fifth costliest hurricane to hit the U.S., with total damages of $88.5 billion.
Katrina, which killed over 1,800 people, made landfall in Louisiana as a Category 3 hurricane after weakening from a Category 5 over the ocean. The hurricane caused flooding of more than 25 to 28 feet above normal tide levels in Mississippi, and over 10 to 20 feet in southeastern Louisiana. Katrina remains a haunting name illustrating that storm surge can be the leading cause of significant fatalities during a hurricane, according to the National Hurricane Center (NHC). “Category 1 hurricanes can still inflict considerable damage to local communities, especially for those living in flood-prone areas and/or mobile homes,” shared Xilei Zhao, a data analyst at the University of Florida specializing in evacuation behavior modeling during hurricanes.
Improving storm surge forecasts could help save many lives, according to Jeane Camelo and Talea Mayo, researchers studying the effects of the Saffir-Simpson scale. They also concluded that climate change could significantly increase the risk of storm surge in coastal areas. Having dominated hurricane classification for over 50 years, the Saffir-Simpson scale has a significant advantage: it provides an immediate measure of hurricane strength. However, according to Wehner, the public needs to understand that the Saffir-Simpson scale does not reflect everything.
