Category 6 Hurricane Dorian?

Steve Miller

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Meteorologist Jeff Masters says the conditions of Hurricane Dorian, with its sustained winds of 185 mph and gusts up to 220 mph, would qualify it for a Category 6 rating, which does not currently exist on the Saffir-Simpson Hurricane Wind scale. Category 5 is defined by “sustained 1-minute average wind speeds of at least 157 mph (70 m/s).” The new level of intensity would help define the extreme rarity of a hurricane like Dorian, which heavily damaged much of Great Abaco Island in the Bahamas in September. [Scientific American]
 
We should always be open to revisiting classification schemes - I'm thinking about how the F-scale morphed into the EF for tornadoes.

I guess for wind alone, perhaps it might be useful to add an extra level...on the other hand, focusing on trying to define a scheme whereby the overall 'potential' for a tropical system to cause damage, or death, might be useful. For instance, many deaths from hurricanes/typhoons are from flooding, either from the rain, or surge...trying to incorporate these into a scale would be of use, especially when trying to communicate the risks, so that folks get away from the 'Oh, it's only a Cat 1, so it'll be fine', ahead of 35-45 inches of rain falling and giving catastrophic flooding.
 
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I’m not so sure that we should, from a public safety perspective that is. If we add a cat 6 rating, it would breed a sort of “complacency” amongst the public with regard to Cat 5s. I think the fact that Cat 5s is the highest category we have definitely adds to the extremity and wow factor, encouraging people to prepare. We already see this with Cat 4s, there is a pretty large preparation/evacuation disparity just between cat 4 and 5. Cool from our perspective but perhaps not in the public’s best interest.

I think the best approach is one that is 3 pronged. Keep the Saffir Simpson scale as is, but add additional 0-5 categories for surge and inland rain.
 
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Jeff Duda

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We should always be open to revisiting classification schemes - I'm thinking about how the F-scale morphed into the EF for tornadoes.

I guess for wind alone, perhaps it might be useful to add an extra level...on the other hand, focusing on trying to define a scheme whereby the overall 'potential' for a tropical system to cause damage, or death, might be useful. For instance, many deaths from hurricanes/typhoons are from flooding, either from the rain, or surge...trying to incorporate these into a scale would be of use, especially when trying to communicate the risks, so that folks get away from the 'Oh, it's only a Cat 1, so it'll be fine', ahead of 35-45 inches of rain falling and giving catastrophic flooding.
There have been many proposed changes/additions to the scales used to classify the intensity of tropical cyclones. Here's one brief article on the subject: AGU article
 
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Good discussion and interesting!

I have to mention though and wonder if the fact that Dorian just basically stalled/came to a crawl over the area really comes into play here?

I mean we all know the situation - a high end cat 5 slams the area with little movement, basically crawling at 4-6mph with 185mph sustained winds (gusting over 200). We are talking MANY HOURS of devastating destructive winds as opposed to the “norm”. Which scientifically speaking caused much more damage than what we might see otherwise or with a “normal”cat 5.

As others have mentioned, there has long been discussions of possibly enhancing the SS scale. But I wonder if we are collectively taking into perspective that you could basically throw out the “norm” because Dorian did what it did in “parking” over the area, which no doubt caused much more additional damage.

Good discussion!
 
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James K

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Certainly an interesting discussion.
I could see some point in adding another level. (but then say you did add a 6 (and maybe 7 as the article mentioned) where do you stop, say for example all conditions were exactly perfect...and you got an extreme storm, well beyond those, and the likes of which has never been seen? Do you then add an 8 for such a beast? (something that would likely never happen again))

I think the biggest thing would be as others have mentioned...the public would start going "This one is only a Cat-4" I'm not going to worry about anything less than a 5 or 6.
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@Lanny Dean:
I think in the case of Dorian you absolutely have to take into account that it parked there for a full day.
I know Tornadoes and the EF scale can't be directly compared to a hurricane(since its a damage scale, not simply a wind scale), but say you got a long lasting one not exceeding "EF4-level wind", and it moved at very minimal speed across a town, there's going to a whole lot less left of the place than if it whips through. Maybe even bad enough that it'd end up rated an EF5.
 
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Not sure about changing the ratings. I think this only serves to add confusion. People might be more inclined to sit out a Category 5 if it's not the top of the scale as it has been for years. I do agree the extensive damage was a result of the slow movement. Damage was also compounded by poor engineering and infrastructure. Hurricane Katrina was only a Category 3, but the storm surge along the Gulf was a Category 5 level. I believe a surge and flood category would be more effective in warning people.
 

Jeff Duda

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Jeff Masters is not known for being a "gimmicky" meteorologist-type person, so I don't really understand why he would come up with this.

As he rightfully points out, such a storm is so rare it statistically wouldn't matter whether it was classified as a 5 or 6 anyway. There is also likely little noticeable difference in impacts between two such hurricanes. If anything, the Saffir-Simpson Hurricane Wind Scale should be standardized so that the category boundaries are regularly placed rather than being irregular as they currently are.

Anyway, this is basically the same thing as arguing that El Reno 2013 should have been an (E)F6. Seems unnecessary to make the change if you ask me.
 
I wonder of any of this is designed to bolster the idea of Global Warming? That is, storms (including tornadoes) are becoming stronger, which is a false narrative. Not that Jeff Masters is promoting this, but he's not the first to suggest raising storm rankings.
I am not sure it is a "false narrative" with regard to hurricanes, especially with regard to their impact. With warmer oceans the frequency of strong storms may well be increasing, and certainly with higher sea levels and with an increased frequency of slow-moving storms (including Dorian, as mentioned above), the impact is increasing. Now I have no idea what the motivation might be behind the suggestion to add another category; it doesn't make much sense to me for the reasons others have mentioned. What I am reacting to here is the attempt to claim that the idea that global warming is influencing storms and their consequences is a "false narrative."
 
Please post records showing there are more intense hurricanes. There have always been very strong hurricanes but most do not make contact with land. Nor is there direct evidence tornadoes are increasing in intensity. You might want to look up the terms "cap," "drought," and study the effects of dust coming off the western coast of Africa during the hurricane season, which could also relate to "global warning" and would have negative effects on severe weather as well. Again, post the actual data before making 3rd. grade, insults. ;)
 
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Certainly an interesting discussion.
I could see some point in adding another level. (but then say you did add a 6 (and maybe 7 as the article mentioned) where do you stop, say for example all conditions were exactly perfect...and you got an extreme storm, well beyond those, and the likes of which has never been seen? Do you then add an 8 for such a beast? (something that would likely never happen again))

I think the biggest thing would be as others have mentioned...the public would start going "This one is only a Cat-4" I'm not going to worry about anything less than a 5 or 6.
---
@Lanny Dean:
I think in the case of Dorian you absolutely have to take into account that it parked there for a full day.
I know Tornadoes and the EF scale can't be directly compared to a hurricane(since its a damage scale, not simply a wind scale), but say you got a long lasting one not exceeding "EF4-level wind", and it moved at very minimal speed across a town, there's going to a whole lot less left of the place than if it whips through. Maybe even bad enough that it'd end up rated an EF5.
Totally agree and great points!
 
Please post records showing there are more intense hurricanes. There have always been very strong hurricanes but most do not make contact with land. Nor is there direct evidence tornadoes are increasing in intensity. You might want to look up the terms "cap," "drought," and study the effects of dust coming off the western coast of Africa during the hurricane season, which could also relate to "global warning" and would have negative effects on severe weather as well. Again, post the actual data before making 3rd. grade, insults. ;)
See the item linked below. Pretty much supports what I said, which was that the frequency of strong hurricanes MAY be increasing, and that the impact of tropical systems is increasing because of higher sea levels. And it is pretty clear that we have had a number of slower moving storms recently, which may be explained in part by a northward shift in the jet stream, resulting in weaker steering currents in the some of the areas where tropical storms occur, resulting in a greater propensity for the storms to stall. And I do not see how accusing people of "3rd grade insults" contributes to a useful conversation.