Hurricane category 6 could be introduced under new storm severity scale
Comments
jliptzin
wtallis
If you live on the coast, following the details of the forecasts and warnings is extremely important. But my experience living a little over 100 miles inland taught me that the hurricane category is a useful predictor to some extent: anything below category 3 would weaken enough on its way inland that it wasn't a higher risk than routine severe thunderstorms, and didn't require any special advance preparations. The winds would merely be coming from a different direction than usual for our area, and only the areas usually prone to flash flooding had to worry about the volume of rain. It's location-specific, but it is possible to usefully distill the local risk profile down to something where the hurricane category tells you whether it's time to start worrying about that storm.
jliptzin
You don’t sound like the average person; perhaps you could even be a local authority :)
EE84M3i
A comparison can be drawn to the scales used for measuring earthquakes. Although the Richter scale is quite common in many parts of the world, in Japan the Shindo scale is primarily used. This measures the local ground shaking intensity, as opposed to the Richter scale which measures the amount of energy released in the quake.
https://en.wikipedia.org/wiki/Japan_Meteorological_Agency_se...
liamwire
I thought the world had broadly moved onto the moment magnitude scale?
varenc
I think you’re in total agreement with the authors of this new system. They’re simply making a new categorization system that is closer to a 1:1 mapping between the classification and what local authorities are saying about potential danger.
It's easier to make the classification a better representation of danger than it is to convince people to ignore the rating and only listen to local authorities.
jliptzin
That’s true
trehalose
This article is about replacing the current scale with one that does factor in more than just wind speed. You're right that it's still just a number though.
nothercastle
I would think there is some legal and liability importance here. If you get another catagory that probably another thing insurance can deny claim for.
bb88
I'm conflicted on this.
Lax building codes in hurricane prone areas shouldn't exist after Hurricane Andrew in 1992 [0].
And then there was the Trump sharpie incident. [1]
Wind speed is the best metric (that's not corruptible by humans yet) that describes how dangerous a storm is.
[0]: https://www.npr.org/2024/10/15/nx-s1-5151844/tougher-buildin...
[1]: https://en.wikipedia.org/wiki/Hurricane_Dorian%E2%80%93Alaba...
varenc
I believe this is the real paper for those curious: https://pure.lib.usf.edu/ws/portalfiles/portal/40758246/Adeq...
This new rating system uses the old system and 2 new rating categories
Wind (from old system, 1min sustained speeds)
Cat 1: 33–42 m/s (~74–95 mph)
Cat 2: 43–49 m/s (~96–110 mph)
Cat 3: 50–58 m/s (~111–129 mph)
Cat 4: 59–69 m/s (~130–156 mph)
Cat 5: >70 m/s (>157 mph)
Storm surge (peak surge height above tide)
Cat 1: 0.75–1.54 m
Cat 2: 1.55–2.34 m
Cat 3: 2.35–3.14 m
Cat 4: 3.15–3.99 m
Cat 5: >4.00 m
Accumulated rainfall (event total)
Cat 1: 100–262 mm
Cat 2: 263–425 mm
Cat 3: 426–588 mm
Cat 4: 589–749 mm
Cat 5: >750 mmquodlibetor
And the following criteria:
(a) The final category can never be lower than the highest hazard-based category;
(b) The TCSS should adequately reflect the case of high potential risk of two or more hazards. We consider a hazard of high risk when its respect- ive category is classified as 3 or higher (equal to the definition for a Major Hurricane on the SSHWS). Whenever (at least) two high risk haz- ards have the same category value and the third hazard has a lower category value, the final category should increment the highest hazard- based category. This implies that a TC scoring a Category 3 on both wind and storm surge, and a Category 1 on rainfall, will be classified as a Category 4.
(c) To warn the general public for an event with multiple extreme hazards, a high-risk TC can be classified as a Category 6 when either 1. at least two of the hazard-based categories are of Cat- egory 5; or 2. two categories are of Category 4, and one of Category 5.
ChrisMarshallNY
Up here, Sandy was a cat 2 or 3, but caused 70 billion dollars’ worth of damage, and killed a couple hundred people. Water did most of that damage.
But about 30 years ago, Andrew swept across Florida like a giant roomba, and did a huge amount of damage. It was a cat 5. Wind did most of the damage.
Not sure how they would reconcile these two types of mega-storms.
mapmeld
Sandy was only a category 1 when it hit NYC. This was a wakeup call and part of why there's been years of rebuilding and hardening of NY and NJ infrastructure afterward https://blogs.law.columbia.edu/climatechange/2012/11/21/what...
Grazester
Yep.It this did much damage because places so far North East never experienced storm and so they never built with that in mind.
In place that experience this kind of weather more often(some parts of the Caribbean), it would have been business as usual the next day and I speak from experience.
ChrisMarshallNY
Not so sure about that.
There’s been some nasty storms, up here. They just happen infrequently.
What made Sandy so bad, was timing. It hit at high tide, and mixed with another storm.
Also, geography. The Long Island Sound (the water between Long Island and Connecticut) can act as a “funnel,” that concentrates storm surges, if the wind is from the northeast, and there’s a number of waterways and estuaries, along the South Shore, that normally act as buffers, but actually turned into concentrators, with Sandy. Several seaside communities got all but wiped out, with boats being docked into the kid’s second-story bedroom.
Southmost Manhattan is mostly reclaimed land. That is naturally prone to flooding. It also has some of the most expensive real estate in the world, so any flooding is guaranteed to be pricey.
Because of the timing issue, I’m skeptical that anyone could predict how bad it got.
Grazester
And I would argue that even if that was the case, if these areas saw more storms, then the likelihood of this occurring would not have been so one-off. They would have built with that consideration.
ChrisMarshallNY
Possibly, but never underestimate the short-sightedness of real estate developers. In places like Florida, they force them to design storm-resistant housing (post-Andrew, mainly).
Up here, after Sandy, any house south of Montauk Highway, is basically uninsurable. So you have a lot of waterfront property, that people can't sell. The insurance companies basically enforce it.
My mother was big into managing stormwater runoff (in Maryland). It was one of her casus belli (She had more than one –She was pretty scrappy).
Real estate developers hated her.
wmichelin
It sounds like under the new ratings, both would be much closer together. It sounds like the water damage caused by Sandy is not articulated in the current rating system. So Sandy might work out to be a 4 or a 5? Not 100% sure of course, but that is my interpretation of the article.
js8
> Not sure how they would reconcile these two types of mega-storms.
Maybe something like free energy in thermodynamics?
msla
[flagged]
ChrisMarshallNY
Boy, you are obsessed. I guess I should be ... flattered?
https://pinkpanther.fandom.com/wiki/Charles_Dreyfus
But it's more likely that this is a simple insult bot, considering what it posts.
jcalx
Feels like something similar to the NFPA 704 safety square [0] — maybe they could copy that to mimic a relatively accepted "danger measurement" format.
Also of interest: hypercanes [1], my hurricane-adjacent Interesting Wikipedia Deep Dive, which (according to Wikipedia):
- require ocean temperatures of 120 °F (50 °C)
- have sustained winds of 500 mph (800 km/h)
- have barometric pressures in their centers sufficiently low enough to cause altitude sickness
- may persist for several weeks due to above low pressure
- may be as large as North America or as small as 15 mi (25 km) — Wikipedia has an unhelpful caption about the size of the "average hypercane" (!)
- extend into the upper stratosphere, unlike today's hurricanes (lower stratosphere)
- due to above height, may sufficiently degrade the ozone layer with water vapor to the point of causing (an additional) hazard to planetary life
BobbyTables2
Interesting thought experiment but if any significant area of the ocean was even 100F, much less 120F, I think we’d be cooked.
throwaway290
as the article says, all you need is a volcano.
jauntywundrkind
I keep meaning to reread Bruce Sterling's Heavy Weather, about a future where the climate is trashed & weather escalates. Amid this, a group of tornado chasers are trying to find the first "F6" class tornado. https://thierstein.net/index.php?view=article&id=355:bruce-s...
Different extreme weather but fun book.
adverbly
Power creep. They should just buff cat 1 and 2.
orev
It’s my understanding that “category 5” means “total destruction”, which is why this hasn’t been done in the past. However if it helps to get the point across about climate change, it would be helpful for marketing purposes.
trehalose
That's not what the proposed change is about. (It's about replacing the scale with a different one that takes into account flooding and other dangers that better reflect the likelihood of fatalities than just wind speed alone. Category 1 hurricanes can sometimes be more dangerous than higher-category hurricanes under the current scale.) I worry that people might not take this seriously because they assume this is a frivolous rebranding to "market" climate change.
ares623
Exhibit A
alehlopeh
Hurricane categories just mean that winds are above a certain threshold. For cat 5 I think it’s 157mph, and that means if the hurricane has winds of eg 170mph it’s still a category 5.
Another problem with this system is that some category 2 or even 1 hurricanes can cause incredible devastation, depending on where they hit. But people see category 1 and they assume it’ll be nothing.
cryptoz
I think you’re referencing the tornado EF scale, not the hurricane Saffir-Simpson scale.
gosub100
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_heimdall
Sorry but that reason for a change feels very coercive. If cat 5 is intended to be total destruction, meaning that anything above the lower bounds for a cat 5 is indistinguishable, there should be no 6.
trehalose
That's not what this is. (The person you're responding to didn't read the article.) They're not looking to add a "total-er destruction" category; they're looking to replace the current scale with one that takes into account more factors than just wind speed, such as storm surge and flooding. Under the current scale, a category 1 hurricane can be deadlier and more destructive than a higher-category hurricane. They want to use a different scale that better indicates the dangers. It goes up to 6 when multiple factors rate 5 on each factor's specific scale under the proposed system.
I think the title of this article is misleading and clickbaity. :/
hedora
Category 6 could also be useful in that it implies multiple threats to avoid.
Evacuation strategies for a cat 5 that’s just storm surge is very different than one that is wind and rain. Either way you lose the city, but with the latter, moving to high ground won’t save you.
bombcar
Total destruction could be “total human-scale destruction”.
You could have “geological changes” above that; reroutes rivers, moves mountains, etc.
creatonez
The National Hurricane Center has figured out pretty well how to depict hurricane danger to the public, but a lot of people don't bother to pay attention to it and go for noisy sources instead. I think it's a good example for how to prioritize important information in general. Every few hours, they put out a selection of graphics:
- A "Key messages" graphic with 2-4 bullet points about what is going on, what is predicted to happen, and specific dangers to look out for. The tone of the text is carefully adjusted for how life-threatening the situation is. This graphic also includes a copy of the two most important visualizations on the right. (Example: https://www.nhc.noaa.gov/archive/2024/HELENE_graphics.php?pr...)
- A peak storm surge graphic showing predicted coastal inundation and destructive wave action (Example: https://www.nhc.noaa.gov/archive/2024/HELENE_graphics.php?pr...)
- A cone to depict the range of predictions for where the hurricane could go, ideally without a confusing line drawn in the center prediction (Example: https://www.nhc.noaa.gov/archive/2024/HELENE_graphics.php?pr...) Arguably this could be replaced with a spaghetti model map, but these can be just as confusing for those unaware of how predictions are depicted.
- A map of the most likely arrival time for hurricane force winds (Example: https://www.nhc.noaa.gov/archive/2024/HELENE_graphics.php?pr...)
- After the main risks are over, a map of continued flash flood and river flooding risk (Example: https://www.usatoday.com/gcdn/authoring/authoring-images/202...)
- A no-frills ad-free weather report livestreamed to social media, so you can gauge how much the pros at the very top level of hurricane meteorology are freaking out about it (Example: https://www.youtube.com/watch?v=GFL-nbFs2Xs)
- A few other graphics and data dumps primarily intended for meteorologists, local officials, and nerds
jpm_sd
They're just trying to compete with Ethernet.
bombcar
People keep saying they need Car 6 hurricanes but I’m smart and know Cat 5e hurricanes are just fast enough for anyone.
eth0up
As a Florida resident and native, I've been telling people for years to brace for a "Goreicane", which is a cat 6 named after Al.
Irma reached +180mph before magically dwindling to a 3 (or weak 4?) just before landfall. By then, we were already without power, so stats were unknown. I made a safety box out of a toolbox into which I stuffed my cat and provisions, as I wore an old motorcycle helmet and combat boots clutching a bugout bag and bottle of courage.
I really didn't expect to do well and had it hit as a super 5, I'd probably not be leaving this silly post.
But cat 6 is real. We'll see it soon.
WaltPurvis
Your recollection of Irma's intensity is not particularly accurate. It was never anywhere near 180 mph "just before landfall" unless you were in the Leeward Islands on September 6. Irma crossed the Florida Keys on September 10 as a weak category 4, with 130 mph winds, but it didn't dwindle to that weak category 4 status, it intensified to it. When it left Cuba and turned toward Florida, on September 9, it was only a category 2 (and there was nothing magical about why it dwindled to a category 2 — it was because it ran into Cuban terrain). It did weaken a bit, down to a 115 mph Cat 3, between the Keys and it's second landfall in Collier County.
Hurricane Dorian, in 2019, was almost a "Cat 6" kind of experience for Florida. It made landfall in the Bahamas with 185 mph winds and then just parked itself there, barely moving, for 24+ hours, maintaining Cat 5 strength the whole time. If it had done that on Florida's east coast, as it was once forecast to, the economic destruction would have been unbelievable.
eth0up
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eth0up
I re-read this thread thinking I may have been unnecessarily harsh. No.
I am apparently supposed to forget my experience of being in the eye of Irma for over an hour, and presumably the hurricane altogether and all memories of my time within it and efforts to mitigate its aftermath - all because wunderboy pasted an AI summary of Irma's path in attempt to further belittle my little post, based on the profound impetus of imperfect punctuation.
If HN can't call out this kind of desperate opportunism, lurking in strange places waiting to trounce on any opening to expose oneself as an erudite hero wielding an elaborate encyclopedic remedy to a misplaced comma, then your future here may involve many bots.
And really, that should be the job of a bot - dealing with other bots or trivial wankers who stand tall and proud upon the bodies they've sucker punched. If so, a bot is welcome to take my place too.
bigmattystyles
"These go to 11"
bitwrangler
I love that movie, and that scene. ha ha.
Esophagus4
Couldn’t you just make 5 1 stronger?
ItCouldBeWorse
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josh_today
[dead]
cranberryturkey
[flagged]
trehalose
This is not a "climate change is getting worse" story, as I think you're implying :/ (I don't entirely blame you--I doubt you read the article, but I do think the title is misleading.) This is just a story of "The current hurricane categorizing system has always failed to correlate very well with deaths and destruction, because it only factors in wind speed. A category 1 hurricane can sometimes be more disastrous than a higher-category hurricane."
Hikikomori
Gore, Obama, Bernie.
cranberryturkey
yup. we'd be living great.
_heimdall
We don't know what Gore or Bernie would have done once in office or how the world would have responded differently to those presidencies. We could be living great, it could have gone even worse, or more likely it could just be different.
johnklos
We do know. Don't both-sides here.
_heimdall
That seems like a common trope recently. How am I both sides-ing this?
Edit: trope may not be the right term here. "Don't both sides it" is a baseless claim meant to shut down a discussion rather than refute, debate, or discuss it.
Arainach
It could not have "gone even worse". Anti-competence regimes are a disaster. Destroying America's alliances, international relations, leadership, soft power, environment, leadership in renewable energy, and more are all disasters that will take decades to recover from if ever (I'm personally leading towards Pax Americana being over and never recovering).
_heimdall
But you simply have nothing to compare against. Are you honestly saying there is absolutely no reality in which those years could have gone worse if the elections went the other way?
Arainach
The Iraq was was entirely unnecessary. It cost $3 Trillion[1], the lives of more than 500,000 Iraqi civilians, the lives of more than 8000 US troops and contractors, and so much more. It built a wave of anti-American sentiment in the middle east and the world. Literally nothing Gore could have done could have come close to that cost.
The Bush Administration turned a moment of universal world support for the US into cynicism and hatred by wasting goodwill on pointless wars. They turned a nearly balanced budget into huge deficits. The Trump Administrations have been, somehow, infinitely worse. No, there is no world in which things went worse.
[1] https://www.hks.harvard.edu/publications/true-cost-iraq-war-...
hedora
We do know that Gore would have been president in the absence of a corrupt judiciary.
Our corrupt judiciary allowed all of the things you mentioned to happen.
_heimdall
How do we know that? We don't know what judicial appointments would have been made, we can only guess and assume they would have been better.
hedora
Gore won in Florida after the votes were counted, but Bush got the electoral college votes.
No honest judge would rule with the majority of the current supreme court.
_heimdall
Sure, I get that. But how does that allow us to know how the last 20ish years would have played out? And how does that let us know as a fact that it would have been better (that's where this thread started)?
bigstrat2003
We do not, and by definition cannot, know what would have happened in a hypothetical alternate timeline. You're entitled to your beliefs about what could've happened, but don't inaccurately state them as known fact. Moreover, "both-sides" as an accusatory term is hostile and not conducive to a good discussion. You shouldn't do that.
jmclnx
Last I heard from weather people, cat 6 is not really needed, wonder if that changed recently.
With NOAA's cuts, the only way I think cat 6 will be add is Trump wants to be the one to create that level and scientists state it is not really needed :)
destitude
The title is wrong, this is about using a completely different scale system.
jmclnx
I read the article and with the title in mind, it made no sense. So I defaulted to the title.
gosub100
[flagged]
jaggs
Yeah we get it that you think climate change is a hoax.
kylehotchkiss
[flagged]
macintux
Probably the other way around, so he can send FEMA and money to Florida and ignore blue states.
ksherlock
Nah, a hurricane that wipes out Mar-a-Lago will get the same FEMA attention as a hurricane that wipes out Club Bedminster.
hedora
You might want to read up on recent changes to FEMA.
It’s now substantially (and intentionally) weaker than it was pre-Katrina. Trump more than rolled back all of the reforms that happened since then.
Heck, in public statements, they patted themselves on the back for “job well done” when they were asked why they didn’t pick up the phone during or after the recent mass casualty event in Texas.
I’m sure there’d be major federal responses and a special allocation of reconstruction funds if either of the Trump properties you mentioned got hit, but it wouldn’t happen via FEMA (and probably wouldn’t even go through congress).
The average person should not even really pay attention to the category of the storm. That is mostly of scientific concern. It measures the maximum wind speed found at the relatively tiny center of circulation which may or may not have anything to do with how destructive the rest of the storm is hundreds of miles away from the center, as the article points out. That can also depend on things that have nothing to do with the storm itself, such as whether it’s impacting an area with lax building codes that is unprepared for storm surge. People should forget about that scale and focus on what local authorities are saying about the potential danger.