Category 6 Hurricanes? Why Not?

Why add a Category 6 for hurricanes? Glenn explains why.

Modern cars can both drive and park themselves. Asking a tiny object called a cell phone a question can get you all the answers. You can buy a tiny airplane with a tiny camera on it and fly it over traffic jams, storm damage, or even your ex-wives’ house, etc…etc…etc.

It’s called progress. Let us not fear changing something first developed 47 years ago!

Currently there's no Category 6 for hurricanes. But there should be.

They changed the Fujita scale, which measures tornado intensity. They already have a different hurricane scale in the Pacific. Building construction has improved a lot since the Saffir-Simpson hurricane scale was developed in 1971.

Building construction? What does that have to do with creating a new, higher category for hurricanes? The “Saffir” part of the scale was a Civil Engineer, who helped base the scale on structural damage and not just wind speeds. And, in 2001, Robert Simpson explained the reason he objected to the creation of a Category 6:

“…when you get up into winds in excess of 155 mph you have enough damage…it’s going to cause rupturing damages that are serious no matter how well it’s engineered.”

Well, it’s 2018 now, and some buildings can withstand 155 mph winds. In fact, Dade and Broward counties in Florida have new building codes requiring “critical infrastructure” buildings to be able to withstand Category 5 winds.


The Saffir-Simpson scale considers the SIZE of a storm. It doesn’t consider the amount of PRECIPITATION it produces. The strict scale has led to mass confusion and underestimation of tragic storms like Agnes, Katrina, Sandy, and Harvey. There is plenty of room for improvement.

Some scientists have suggested completely new scales that try to better account for multiple storm dangers (such as Kerry Emanuel’s “Hurricane Intensity Index”). In the meantime, why not expand the current scale to account for the “strongest of the strong”?

Damage doesn’t go up in a simple way as winds increase. It’s an exponential increase (double wind speed and damage is 4 times greater). That makes it even more important to have a better damage scale.

The current wind speed ranges are:
*20 mph for a Category 1(74-95 mph)
*14 mph for a Category 2
*18 mph for a Category 3
*26 mph for a Category 4

So if we have a reasonable range of 22 mph for Category 5, that leaves 180+ mph (sustained winds) for Category 6. If we do that, only 7 hurricanes in the Atlantic/Gulf/Caribbean rate that high:
*1935 “Labor Day” hurricane (185 mph)
*1980 Allen (190 mph)
*1988 Gilbert (185)
*1998 Mitch (180)
*2005 Rita (180)
*2005 Wilma (185)
*2017 Irma (180)

Who does it hurt to put those 7 in their own category?

As explained above, the implication that a 190 mph hurricane won’t cause significantly more damage than a 160 mph hurricane has been shattered. That is no longer a reasonable excuse.

There are more Category 4 and 5 hurricanes now than in the past-even the recent past. In my above example, there was only ONE Category 6 before 1980, but 3 since 2005. The increase has already begun, and this trend is bound to continue.

The main graphic that comes with the above research shows the strongest storms have increased the most since 1980.


And what about the future? A new study by scientists at the National Center for Atmospheric Research (NCAR) used 22 actual hurricanes and “placed” them in the average climate expected by late this century. What would change?

The basic answers were not surprising to many climate scientists, but the amount of the changes were remarkable. Take Hurricane Ike (from 2008). It could have 13% higher winds, moved 17% slower, and be 34% wetter in that warmer future climate. The combination of “wetter” hurricanes plus slower movement multiplies the future flood risk. That means more Harvey’s.

Some of the modeled storms did weaken a bit, or move a bit faster-but none were drier. The average rainfall increased 24%!

And the expected intensity increase would just continue the trend seen in the 1980-2016 trend graphic above. Some computer models project fewer overall hurricanes in our warmed future. But it’s the most intense ones that cause, by far, the most loss of life and damage. They are already known as “The Greatest Storms on Earth”. These new studies show that our changing climate already is, and will continue to make them worse in the future.

Category 6? Why not?

Contact Us