| Jeff Masters and Bob Henson's blog covers it in a February 5th blog post: https://yaleclimateconnections.org/2024/02/does-the-saffir-simpson-scale-for-hurricanes-need-a-category-6/ A new paper this week has brought up the topic again. I've usually been against it. Looking at the damage multiplier image they have in that articles makes me slightly more understanding of it, but I still don't think I like the idea. I don't see the idea gaining too much traction. The authors of the new paper do not argue that the National Hurricane Center, or NHC, should adopt a new Category 6 rating for their real-time hurricane forecasts since detailed sociological research would be needed to determine if this is an effective messaging strategy to protect lives and property. Any move to expand the Saffir-Simpson scale would have to come from the NHC, and there is little support for such a move from the experts there that I have heard from. However, talking about hypothetical Category 6 storms is a valuable communication strategy for policymakers and the public, because it is important to understand how much more damaging these new superstorms can be. Hurricane damage is an exponential function of the winds, and the difference in damage potential between a low-end Cat 5 with 160 mph winds and one with 195 mph winds (the lower end of the hypothetical Cat 6 rating) is more than a factor of four, according to NOAA (Figure 3). I agree with the above. I would wonder how the public would take that. If a category 3 hurricane was then in the bottom half of the scale, I think that would make some people take storms like that less seriously. Even if you had a category 5 hurricane coming toward you, some might say, well at least it's not a 6. I also think of a category 6 label as almost a joke. Maybe because it was Jeff Masters' old blog name for awhile. Maybe some ridiculous sci-fi weather disaster movies have used it too, I don't know. I think communicating that a strong category 5 hurricane, perhaps beyond what anyone has ever experienced in a basin, is more effective than anything. I think adding a category would weaken the other categories damage potential in some people's minds. Maybe not immediately, but maybe if people grew up always knowing there were 6 categories. Or maybe with the frequency of powerful storms, maybe they would still understand, I don't know. In the Atlantic a potential category 6 storm would be an extreme rarity, especially talking about for a landfall, though eventually it might just be something that occurs once or twice in people's lifetimes as the water warms. The Pacific, mainly the West Pacific, is where they have storms like that more often, but they don't use the Saffir-Simpson scale. A little more from Wikipedia about past times this has come up: https://en.wikipedia.org/wiki/Saffir%E2%80%93Simpson_scale#Proposed_extensions In an apparent 1991 interview with Robert Simpson he said this: DI: Dr. Simpson, in your opinion, since the Saffir/Simpson scale is an open ended scale, do you think that hurricane windspeeds could become a category 6 or 7? RS: I think it's immaterial. Because when you get up into winds in excess of 155 miles per hour you have enough damage if that extreme wind sustains itself for as much as six seconds on a building it's going to cause rupturing damages that are serious no matter how well it's engineered. It may only blow the windows out, but on the other hand, it can actually rupture the stairwells, the elevator wells and twist them, and it's happened in many buildings so that you can't even use the elevators after they've experienced this. So I think that it's immaterial what will happen with winds stronger than 156 miles per hour. That's the reason why we didn't try to go any higher than that anyway. I disagree about the way he framed that, but I have always seen it as a category 5 hurricane might just destroy most everything. The stronger it is, the more pieces it's going to be in. Sure, some buildings would withstand a "weaker" category 5, but you don't want anyone to try it out. You don't want someone staying for a 5 and only evacuating for a 6. And of course, this is only talking about the wind. I think it's a bad idea to focus on the wind scale so obsessively. It ignores all the other aspects of the storm, including surge. I just don't think a lot of people understand the current ways of informing them about hurricanes. I think changing the scale would just lead to more confusion. But it's good that people are talking about it I guess. It lets them know that storms like this are possible and might be more common in the future thanks to a warming climate, even if they are still exceptionally rare in the Atlantic. |