Amid warming oceans and increasing rapid intensification of tropical cyclones, a new study suggests expanding the hurricane wind scale to include a Category 6 with winds over 192 mph.
Climate researchers published a study in the Proceedings of the National Academy of Sciences journal that considers adding a Category 6 to the long-used Saffir-Simpson Hurricane Wind Scale due to more intense tropical cyclones fueled by warming oceans.
Hurricanes in the Atlantic Basin are assigned a Category 1-to-5 rating based on their maximum sustained winds. This hurricane category method is called the Saffir-Simpson Hurricane Wind Scale,
and the National Hurricane Center has used it to evaluate the strength of hurricanes since the early 1970s. It’s the most used metric the public recognizes but does not extend beyond a Category 5 storm with winds topping out at 157 mph or stronger.
The study authors say because the scale is open-ended, it can lead to the public underestimating the risk of a storm, which is becoming increasingly problematic with warming oceans fueling rapid intensification.
According to the National Hurricane Center, rapid intensification occurs when a tropical cyclone’s maximum sustained winds increase by at least 35 mph in a 24-hour period. Another MIT-led study found that rapid intensification rates are expected to become more common because of climate change.
After looking at hurricanes between Category 3 and 5 over the past 42 years, the study authors said they found half of the 197 tropical cyclones rated a Category 5 happened within the past 17 years.
Five of the storms would have met the hypothetical Category 6, including Typhoon Haiyan, which made landfall in the Philippines in 2013, killing more than 6,300 people.
The study also included Hurricane Patricia as one of the five storms to meet this proposed new wind category. The 2015 monster storm with winds topping out at 207 mph.
