When a meteorologist talks about a Category 2 or Category 4 hurricane, do you know what they mean? For people living in hurricane-prone areas like Florida and Texas, this categorization system can be a life saver.
It’s known as the Saffir-Simpson Hurricane Wind Scale, and this system is used to rank hurricanes by their potential destructive power, using a five-category scale.
Here’s a quick explanation of how the Saffir-Simpson Hurricane Wind Scale was created, and why it’s crucial for at-risk regions every Atlantic hurricane season.
Who Were Saffir & Simpson?
The Saffir-Simpson Hurricane Wind Scale was unveiled by structural engineer Herbert Saffir and meteorologist Robert Simpson in 1973.
Saffir was working as a county engineer in South Florida when he became interested in how a hurricane’s strong wind impacted beachside buildings and houses. This led him to open a structural engineering firm in 1959, where he specialized in how these intense conditions affected structures. His expertise in the field led to him to assist with developing building codes throughout South Florida.
In 1969, Saffir began working on a hurricane intensity scale as part of a project with the United Nations. Saffir and his team sought to find ways to minimize the destruction caused by hurricanes, especially in poor countries that might not have adequate emergency response systems.
Inspired by the rating system that already existed for earthquakes, Saffir believed that hurricanes needed a similar system for scaling. He developed a five-category system and presented his work to Robert Simpson.
The Saffir-Simpson Hurricane Wind Scale
At the time, Simpson was working as the head of the National Hurricane Center (NHC). As the public’s main source of information about these catastrophic storms, Simpson wanted a system that was easy to understand and that would actually help people prepare for an upcoming hurricane.
The two innovators worked together to assign wind speeds for each category. Simpson also added the effects of flooding, storm surge, and pressure ranges. They introduced the system to the public in 1973, where it was used to rank hurricanes for more than three decades.
Since that initial scale, the system has gone through two changes. In 2009, the NHC stopped using storm surge, pressure, and potential flooding as determining factors to categorize a hurricane. In 2012, a slight change was made to adjust the Category 4 wind speed by 1 mph at its minimum and maximum.
What is the Saffir-Simpson Hurricane Wind Scale?
Saffir and Simpson’s scale ranges from Category 1 to Category 5, and is based on a hurricane’s sustained wind speed. To measure this velocity, the NHC determines the highest wind speed a storm can maintain for a full minute. The full breakdown is:
Winds ranging from 74 to 95 mph. You can expect minor damage to your property with a Category 1 hurricane. The biggest threat posed to people and animals is typically from flying or falling debris, though staying inside will protect them from a majority of these risks. Power outages are possible if a power line or tree goes down.
Winds ranging from 96 to 110 mph. Extensive property damage can occur, and your home’s roofing, siding, and glass windows are more at-risk for breakage. Structural damage can also occur in apartment building and mobile homes. It’s not uncommon to experience a power outage that lasts up to a few weeks following a Category 2 storm.
Winds ranging from 111 to 130 mph. Those living in mobile homes are often urged to evacuate due to the risk for severe damage to both the property and occupants. Intensive flooding can occur, and it’s not uncommon for electricity and water to be unavailable for anywhere from several days to several weeks following a Category 3 hurricane.
Winds ranging from 131 to 155 mph. A Category 4 hurricane can cause catastrophic damage to structures, people, and animals. Power and water outages can last anywhere from several weeks to several months following a storm of this level. Residents in areas that are prone to flooding are often asked to evacuate to higher ground.
Winds at or greater than 155 mph. This is the highest ranking a hurricane can earn, and cause catastrophic damage to any area it hits. These storms have the power to wipe out entire shopping centers, uproot trees, and cause power/water outages that can last for months. One of the most infamous Category 5 hurricanes was 2005’s Hurricane Katrina.
We have a lot to thank Saffir and Simpson for. Their scale has helped the world understand the damage that hurricane-force winds can cause, thus helping people better prepare for these destructive storms and know the best way to take action and stay safe.
It turns out, Saffir and Simpson aren’t the only ones with a severe weather scale. Have you heard about the Waffle House Index? Click here to find out more.