For more than 50 years, predictions at the National Hurricane Center have used the Saffir-Simpson Hurricane Wind Scale (SSHWS) to classify hurricane power. This scale, which brings hurricanes from Category to Category 5 to Category 5, is based only on one meter: the maximum continuous wind rate.
It wasn’t always like that. Until 2012, the SSHWs also took into account the fluctuation of central printing and storm, but NHC eliminated these factors to reduce public confusion. The problem is that increasing global temperatures worse the danger of more than one hurricane, not only wind speed. In recent years, extremely busy storms such as Milton, Patricia and Typhoon Haiyan have started a discussion on whether it was time to create a category 6.
For this day, we asked more than one expert which side of this discussion. Although some of them are more open than others, they all admit that adding not only one category to SSHW is not the answer – although a few hurricanes have exceeded wind speeds. Instead, some claim that transmitting hurricane risks in a world of warming may require a completely rethink of the scale, while others believe that the current system should remain unchanged.
Jennifer Collins
He is a professor at the University of South Florida University, who developed an alternative to the SSHW.
The current SSHWs – as the name suggests – is based only on the wind. Regarding this scale, my thoughts about category 6 are not needed to cause total destruction of a category 5 on this scale. There was a lot of discussion in the science community ten years ago and I believe there was a general consensus.
Ours New recommended scaleTropical cyclone sensitivity scale (TCSS) thinks that the wind usually constitutes only 10% of deaths. Storm fluctuations are roughly 50% and about 30% in the rain. Our scale includes all three of these hurricane dangers and assigns a category of each of each. It then gives a general category that will never be lower than the highest category given to dangers.
For example, in 2018, Hurricane Florence will be a cat in Wind for Wind, a cat 4 for storm fluctuating and a cat for rainfall. So, the general score would be a cat 5. If you think about the loss of floods and life, I believe that people who live through him will agree that the name of a cat 1 made by Sshwh does not adequately reflect the other dangers they experience. According to my previous evacuation research, people underestimate the risk of a low -category hurricane, even a tropical storm when considering the evacuation decisions.
The recommended TCSs also reflect the high potential risk of two or more dangers. When the category is classified as 3 or higher, we consider a high risk of danger (equal to the definition of a large hurricane in SSHW). This increases the overall category of hurricane to 1 when there is at least two high -risk dangers in the same category and a lower category of the third danger. Therefore, a tropical cyclone with a CAT 3 score for both wind and storm fluctuations, but a CAT 1 score for rainfall is classified as CAT 4.
Therefore, a high -risk tropical cyclone can be classified as CAT 6 in TCSS in two scenarios. At least two of the dangers are cats 5 or two danger cats are 4 and one cat is 5. This is designed to warn a hurricane of the public with more than one extreme danger.
Brian McNoldy
Miami University Rosenstiel Deniz, who has been watching and writes about tropical Atlantic activity since 1996, is a senior research assistant at the School of Atmosphere and World Science.
My general idea is that adding a cat 6 is not necessary and will not add any value to the current information package.
Since 1980, Cat 5 hurricanes have made up only 5% of all the storms called globally. They made up 4%in Atlantic. I was not convinced that these small storms were divided into smaller boxes.
The most intense Atlantic Hurricane in the recording was Allen, Allen in 1980 and the maximum wind of 190 miles per hour. Since then none of them have reached this sign. The threshold for a cat 6 is at least 193 miles per hour This studyFor example, no Atlantic Hurricane is qualified.
In addition, dividing these small numbers into smaller numbers does not change risk communication. The National Hurricane Center explains after the 5 hurricanes of the cat, which will occur as follows: “Catastrophic damage will occur: a high percentage of framed houses with total roof failure and wall collapse will be destroyed. Falling trees and power poles will isolate the settlement areas. Power cuts will last for months.
If one had to go ashore, what additional risk communication would be for the category 6?
Liz Ritchie-Thyo
At the University of Monash University, the World, Atmospheric and Environmental School, he served as the Deputy Director of the University of the University of the 21st century.
Answer “No.”
The SSHWs were developed by a hurricane expert and a wind engineer in the USA and put maximum wind thresholds on the landing levels. If a cat is 5 in a hurricane SSHW, this catastrophic damage is expected. Therefore, a new “Cat 6” is not meaningful in terms of transmitting threat levels.
For all tropical cyclone basins, all hurricane classification systems are based on maximum continuous wind speeds. Whether the SSHWs in the North Atlantic and the East North Pacific, or other scales in the West North Pacific, the Indian Ocean and the South Pacific, but the main idea is the same: when a hurricane reaches the highest category, disaster damage is probably.
The main limit of existing classification systems is not that they do not go high enough to communicate the threat sufficiently, but they are based only on the wind threshold that does not capture all possible dangers associated with hurricane falling on a land.
What we really need is a new “multi -factor” categorization system that can transmit more than one threat of danger, including wind, storm fluctuation, rainfall, floods and landslides. Different hazards will be more important depending on the replacement of the deduction. Wind, waves and storm fluctuations along the coastline are extremely important, and the sludge shifts caused by flood and heavy rain are more important in the interior.
Moreover, the maximum continuous wind speed, waves and storm fluctuations that create storm force winds does not capture the scope of the winds. The larger the area of these harmful winds, the larger the potential effect of the storm fluctuation. Similarly, the maximum wind density is not directly related to heavy rainfall. Although it is true that cat 4 and 5 hurricanes produce heavy rain, Cat 1 hurricanes can also produce heavy rain.
Therefore, a multi -factor categorization system, which can transmit the risk of various hazards, will be more useful than adding an extra category to the current scale.
Daniel Brown, NHC Hurricane Specialist Branch Chief
NHC Hurricane Expert Branch Chief. In this role, it controls the unit that publishes tropical cyclone forecasts and warnings for Atlantic and East North Pacific Hurricane Basins.
Currently, there is no effort to replace SSHW in Noaa or to add a new category 6.
Storm categories only transmit the danger of wind. While the public warns about the dangers associated with tropical systems, the national hurricane center conveys a wide range of dangers, including wind, rainfall, hurricane and torn currents.
Since most of the deaths caused by tropical cyclones are caused by water hazard, we do not overdo the wind danger by focusing too much to the category. Storm fluctuations, rainfall and interior flood and dangerous surfing causes about 90% of tropical cyclone direct deaths in the USA
In addition, the category of Saffir-Simpson Scale 5 captures the worst damage labeled as “disaster damage .. Regardless of whether the storms are stronger, the damage cannot worse than “disaster”.
Mark Bourassa
Meteorology Professor at Florida State University of Florida Ocean atmospheric Performance Research Center for air/sea interactions, surface water waves, identification of tropical disorders and tropical cyclones.
Better -scale structure and advanced measurements may be claimed that the storms will allow us to classify it as stronger than CAT 5, but would it be beneficial for any reason except to keep a more detailed record?
I find a hurricane as much as I doubt that a new category will have any impact on the public response. People who do not evacuate or evacuate for the cat 3 or 4 storms often do not evacuate or evacuate for a stronger storm.
There are other types of information that estimators are trying to communicate clearly, and this is more useful than defining a new storm category. Storm fluctuation estimated maps are a good example of effective improvements in communication of hurricane hazards.
I hope to see clear messages about the possibility of various wind speeds that reach the region where I live and work. I also welcome more information about the envisaged internal floods. This information will be much more useful than making a distinction between a CAT 5 and CAT 6 storm for both public and emergency management.
However, the arguments I have made against creation of a Cat 6 are not particularly fair, because the purpose of such an assignment seems to be recorded instead of giving too much additional information. There is no reason not to follow all these options, but I want to see better probability maps of key hurricane dangers by talking as a living near the Gulf coast.
