Should there be a Category 6, or even a Category 7, to classify extra bit tropical cyclones like Haiyan?

Some tropical cyclones labeled Category 5 are much stronger than others. It has been suggested that we would be smart to extend the system to have a Category 6 and maybe even a Category 7 to allow the additional severity of these storms to be indicated when they are being spoken of in the news or by officials in charge of scaring people into doing the right thing, like running away or staying indoors.

There is resistance to this proposal that comes from two mostly distinct places. One is the community of those who deny the science of climate change, or climate change itself, or science itself. Their motivation is to not allow the so called “alarmists” (those who are alarmed at the changes happening on our planet) to have a tool to point out that severe weather can be very severe indeed. The other is the subset of meteorologists who are actually correct, in a way, when they point out that the Saffir Simpson scale, the scale with the five categories, can’t be extended because of the way it is built, but who are very incorrect, I think, when they point out that extending the scale would damage the most important available tool for scaring people into running away (or staying indoors).

The reason the Saffir Simpson scale can’t be extended is this. The scale has five categories of hurricanes. The first category, Category 1, is the category a hurricane that is at or near the minimum level of strength can be and still be called a hurricane. The top category, Category 5, is the level of strength at which a hurricane flattens a wood-frame suburban American neighborhood and takes out the overhead utilities to the extent that nearly full replacement, not just putting up a few new lines, is required. In other words, from the point of view of the vast majority of Americans living in regular homes or townhouses around the country, a Category 5 hurricane is total destruction of your way of life. You have to move, rebuild, live in a FEMA trailer for a while, etc. From the point of view of the citizen, the rescue workers and first responders, the parts of the government that are in charge of taking care of the refugees, and the meteorologists who discuss these things on the TV, a Category 5 hurricane is effective at the top category because it is as bad as it gets.

I would like to point out three reasons that this is wrong. I’m not actually going to suggest that we replace the Saffir Simpson scale with a different measure. Rather, I’m going to suggest that we add new measures and use them (there already are other ways to measure hurricanes).

The first thing that is wrong is that people are already stupid about hurricanes. The meteorologists don’t want to make a Category 6 or 7 because they don’t want a Category 5, which is total destruction of your American Dream, to look smaller. They want Category 5 to look extra bad because it is, in fact, about as bad as it gets. However, people already don’t get Category 5. For one thing, people think that a hurricane “arrives” when it makes landfall. This landfall thing is a thing Meteorologists use. This is when the eye reaches the shoreline. There are important meteorological things that happen when the eye reaches the shoreline and it is highly convenient and very polite of these monster storms to have something that serves as a virtual point on the map indicating their center so we don’t have to have an endless debate about when the storm “arrives.” But if you are sitting there on the coastline thinking that the hurricane that is bearing down on you hasn’t gotten there yet when the eye is 20 miles away but 130 mph winds are taking off your roof and a storm surge has already broken the dike and all the escape routes are already flooded then you don’t understand that hurricanes are huge. And, I’ve seen meteorologists standing in the 100+ mph winds talking about how the hurricane has not arrived yet, and we’ve all seen the Bush administration claim that Katrina did not cause flooding in New Orleans because the flooding happened before the hurricane arrived, because she had not made landfall yet.

So, now we might say something like “a Category 3 hurricane will come ashore on the Louisiana-Mississippi border” and people who live a ways away have to be reminded “oh, and there will be hurricane force winds over there where you live too” as though this was a separate thing. Hurricanes are not eyes of hurricanes, and the wind field of a certain category of hurricane can very large or very small, and what you have to do because a hurricane is coming may be very unconnected to to simplified and incorrect conceptualization of the hurricane that the Saffir Simposon scale or the Storm Stud on the beach gives you.

On top of this, the Saffir Simpson scale refers only to maximum sustained wind, not the size of the wind field, the intensity of storm surge, or the location and extent of coastal flooding, or the rain and subsequent flooding which may depend on topography, and the tornadoes that spin off, etc. etc. It is only telling us one thing, telling it to us poorly, ignoring things that are more important, and ignoring the context of ignorance and confusion that surrounds these storms.

And speaking of ignorance, there is this: People misunderstand storms. Should a scale of measurement of a storm’s effects be designed to accommodate ignorance, or to accommodate the need to measure the storm’s effects?

Anyway, those are the first two reasons to not fetishize the Saffir Simpson scale. It is part of the ignorance, not an anecdote to it, and it ignores some of the most imprtant aspects of the storm, or at least, fails to correlate well with those things.

The third reason Saffir Simpson is sometimes problematic is because it is, explicitly, a level of destruction meter and it sometimes does a poor job at that. Notice that the number of miles per hour that the winds much reach to jump to the next category is not linear. Some of the categories are 19 mph ‘wide’ and some are 24 mph ‘wide.’ This is because Saffir Simpson categories are not wind speed categories no matter how much they look like they are. They use windspeed but they are categories of destructiveness. Here is the Saffir Simpson scale, officially, from the National Weather Service:

  • Category 1: Very dangerous winds will produce some damage: Well-constructed frame homes could have damage to roof, shingles, vinyl siding and gutters. Large branches of trees will snap and shallowly rooted trees may be toppled. Extensive damage to power lines and poles likely will result in power outages that could last a few to several days.

  • Category 2: Extremely dangerous winds will cause extensive damage: Well-constructed frame homes could sustain major roof and siding damage. Many shallowly rooted trees will be snapped or uprooted and block numerous roads. Near-total power loss is expected with outages that could last from several days to weeks.

  • Category 3: Devastating damage will occur: Well-built framed homes may incur major damage or removal of roof decking and gable ends. Many trees will be snapped or uprooted, blocking numerous roads. Electricity and water will be unavailable for several days to weeks after the storm passes.

  • Category 4: Catastrophic damage will occur: Well-built framed homes can sustain severe damage with loss of most of the roof structure and/or some exterior walls. Most trees will be snapped or uprooted and power poles downed. Fallen trees and power poles will isolate residential areas. Power outages will last weeks to possibly months. Most of the area will be uninhabitable for weeks or months.

  • Category 5: Catastrophic damage will occur: A high percentage of framed homes will be destroyed, with total roof failure and wall collapse. Fallen trees and power poles will isolate residential areas. Power outages will last for weeks to possibly months. Most of the area will be uninhabitable for weeks or months.

See how I did that without even mentioning wind speeds? Notice that these categories are levels of destruction mainly of human-made structures. Saffir and Simpson did not invent destruction. They did not invent wind speed. What they did was to list levels of destruction that make sense, like how bad the power outages will be or whether or not houses will get knocked down just here and there or everywhere, and how long after the disaster everything will be a mess. Then, Saffir and Simpson linked these categories of destruction to wind speed thresholds that do not form even categories. This is not a set of wind speed categories. This is a set of categories indicating levels of destruction that, of course, go up with more wind speed but not in a linear fashion.

I note that when asked about a Category 6 storm Simpson had this to say, quoted in Wikipedia:

According to Robert Simpson, there are no reasons for a Category 6 on the Saffir-Simpson Scale because it is designed to measure the potential damage of a hurricane to manmade structures. Stating that “…when you get up into winds in excess of 155 mph (249 km/h) 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”

As brilliant as the Saffir Simpson scale is, there is a problem with categorizing levels of destruction beyond the fact that much of the destruction and death may be flooding which is not addressed directly by the system. A hurricane in a hilly third world country with a lot of erosion due to deforestation, and where people live in homes that can be blown down more easily, are not going to experience the same level of destruction as people who live in a first world country with the experience of a major typhoon and who rebuilt their homes to be concrete bunkers with storm shutters and excellent drainage systems in place (a friend of mine lives in a home on Osaka that is built like this; there was a major typhoon there years ago and this is how people there rebuilt). Saffir Simpson has its uses but these uses to not apply globally or across time as conditions change.

The reason people are asking about a new category is this: We may need a new baseline. This is true with climate change in general. If we normally get Category 1 through 5 storms and the 5’s are rare and only barely go over the line that defines a Category 5 storm on the Saffir Simpson scale, then we don’t need to change. But if there is an increasing number of storms that turn into super storms and go many tens of miles over the Category 5 line, as Haiyan did (with wind speeds of 195 mph, enough to make it a Category 6 or even 7, if we extended the scale) then we should acknowledge the shifting baseline by adding a category or changing the system.

I think we should keep Saffir Simpson because it is already in use, but add categories every 20 mph as needed. But in addition we should add or begin to use more of the other ways of measuring a hurricane, that indicate the overall strength and size of the beast. The general public might be too stupid, according to some, to handle even a tiny bit of complexity, but if you live in a hurricane prone area knowing that hurricanes have two or three pertinent characteristics is important and you better know that. Knowing what a given hurricane that is coming your way looks like is important and you better know that. Knowing that the total energy of a storm is X, the likely destructive force is Y (from a modified Saffir Simpson that has more categories), that you are in a zone of likely wind strength of Z and if you are on the coast likely storm surge of F sounds like an awful lot to know, but it is less information and less complicated than the following:

  • The average bread recipe.
  • The variables you used to chose your last car.
  • Using the TV remote.
  • How to use a pull tab or slot machine.
  • Managing death certificates and other paperwork of your relatives who died because they didn’t pay attention to the hurricane.

Comments

  1. #1 Veli Albert Kallio
    England
    November 10, 2013

    I think hurricanes with sustained wind speeds at 320 km/h and with top windspeeds in gusts reaching 396 km/h deserve own category. 400 km/h is roughly half the speed a commercial airliner ploughs through the air and wind speed in many smaller tornadoes. However, the storms eye wall in Philippine storm is far bigger than in tornadoes or supercells that also cause highly destructive circular winds.

  2. #2 Ted Irwin
    Australia
    November 10, 2013

    Yes we have to acknowlege change and thus create new categories to describe the changes as they arise. I’ve been in 120 kp/hr in Japan. They called it a typhoon. To be honest it was just like a strong wind in Australia. However this new mega typhoon in PPN is way way out there.

  3. #3 Mike
    November 10, 2013

    I went through Cyclone Yasi (downgraded to cat 4 just prior to the eye crossing the coast) in north Queensland a few years ago and was amazed how unprepared many people were, especially since they had experienced an equally destructive cyclone (Larry) just 5 years earlier. Even in the afternoon, just 8 hours before Yasi’s eye was due to cross the coast, people were panic buying everything they could get. There were arguments at the local petrol station because people weren’t perceived to be moving fast enough by the queueing motorists. It was pandemonium. When I first arrived there in 2009 I experienced a category 1 cyclone (Ellie) on my first night. At the time it was a little scary although in hindsight after Yasi, not really, and therein lies the problem. People become complacent and they fail to prepare in a timely fashion. They experience a cyclone or two and it’s all a bit blase. They forget. Prior to Yasi making landfall, there were times when his windspeeds may have been high enough to bestow a higher category than 5 on him. Perhaps proper reporting of that may have sparked more preparedness and less last minute panic.

  4. #4 jyyh
    November 10, 2013

    possible definitions for category 6:
    cat6 – over 185 mph ~300km/h at 1-min sustained wind (if one needs a definition:”only sports cars placed on flat solid ground may stay upright and undamaged if faced to the wind and there’s no flying debris” ;-) ), and Haiyan would be cat6 along with a couple of predecessors. (Camille would possibly be the only Atlantic hurricane make into that)
    cat6 – under 890 mbar (there would have been 18 systems already and Haiyan would have been in cat5)

    the 186mph limit would somewhat fit to an extension of Beaufort scale and would be 23 in that. (I can’t really fathom the vastness and force of these systems. see f.e. the images from the Guiuan reconnaissance flight at Masters’ blog comments)

  5. #5 Greg Laden
    November 10, 2013
  6. #6 Judy Anderson
    Usa
    November 10, 2013

    I think you are on to something.

  7. #7 Omega Centauri
    November 10, 2013

    You also have the fact that peak wind speeds are vary on short time scales, especially due to eyewall replacement cycles, so even if your location is in a direct path of the worst sector -and the storm doesn’t deviate from the predicted path, your experience may be off by a category or more from the forecast. Add in the uncertainty of the storms path, and local effects (topography or whatever), and there is already a lot of uncertainty. So the cat number can at best be only a crude indicator of how much respect the storm deserves.

  8. #8 Connie
    Minnesota
    November 10, 2013

    Let’s just call it a Category 6 typhoon because it was a Category 6. I think even the meteorologists and scientists are in shock right now. It will take them a little time to get through the denial and then they will create the new category.

  9. […] Greg Laden’s Blog: […]

  10. #10 4TimesAYear
    November 11, 2013

    “We may need a new baseline. This is true with climate change in general.”
    Really?
    Who’s to determine the “baseline”? What’s “normal”? We’ve been through ice ages and warming periods. Tell me please, what’s “normal”?

  11. #11 Harry
    New York
    November 11, 2013

    This tells me that the category scale is US centric and no relevance whatsoever in other countries where construction and infrastructure ranges from solid brick homes to meager wooden shacks.

    On the day that the news is 10,000 dead in Asia due to a hurricane, this article is disturbing in its US centricism because science ought to be universal. I guess the rest of the world’s climate scientists ought to work on developing a categorization system of global relevance because US meteorologists are entirely consumed by american interests, which is a betrayal of the moral and ethical compulsions of science.

  12. […] There Be A Category 6 For Hurricanes? Greg Laden brings up the pros and cons in a post at scienceblogs.com; here’s a clip: “…There is resistance to this proposal that comes from two mostly […]

  13. #13 Sou
    November 11, 2013

    It makes sense to add a new category for these super storms.

    To give a parallel example, in Victoria and probably now other states in Australia there is a new fire danger rating to match the sort of conditions we can face these days. Fire danger ratings used to go from low-moderate, high, very high, severe to extreme. Now there’s a category beyond the “extreme” and it’s called Catastrophic or Code Red. Which means “get the hell out if you’re going”.

    Problem is, of course, that as often as not the Code Red day will apply to a thousand km or more in every direction, so there’s no place to go. (Not quite true as most localities have designated “safe” areas. How safe they are on a Code Red day if a fire breaks out will depend a lot on the wind.)

  14. […] and killing as many as 10,000 to date.  Some have asked whether or not it is necessary to create a new category of storm to capture the magnitude of the typhoon, much as Australia’s Bureau of Meteorology […]

  15. #15 G
    California USA
    November 11, 2013

    Seems to me there are two separate and distinct needs here.

    1) A system of measurement that will be useful for meteorologists and climatologists and others who are concerned with scientific and technical issues and who can be properly trained in the use of the system.

    2) A means of warning the public, that is easily understood by the vast majority including by people with little to no formal education who may also be illiterate.

    I don’t think there’s any good way of filling both needs with one system. So if it was up to me, I’d create (1) on the basis of the measured characteristics of storms, including a weighted mix of a) average wind speed, b) peak wind speed, c) diameter of storm across its largest axis, d) air pressure.

    Then for (2), something as simple as a three-color alert system: Yellow for mild to moderate damage expected, Orange for moderate to severe damage, Red for catastrophic damage. These would be based on local conditions, taking into account the geography, economic condition of the people, quality of construction, available escape routes and reinforced concrete shelters, and available supplies along evacuation routes. The alert system could be broadcast over radio & TV, colored flags posted on designated buildings, and a siren system used to get peoples’ attention. (And, there’s nothing like a continuous siren wailing a red alert all day & night without stopping, to annoy the hell out of even the hard-core stragglers enough that they’ll evacuate.)

    After that I’d go for saturation media coverage, and training of all school children, to be sure the system was universally understood. Also hold drills once or twice a year, with some kind of economic reward-incentive to enable poor people to evacuate or go to public shelters as the case may be. (RIght, “somewhere over the rainbow, blue birds fly…” But if the value of human life means anything at all, the world will find a way to allocate resources to deal with this.)

    Any locale that gets flattened should only be eligible for rebuild if the rebuild is going to be to “bunker” standards. If that means living in reinforced concrete domes with port-holes for windows, so be it, and people who object to the aesthetics can move inland. In some cases there should be no option to rebuild: everyone relocates inland, government makes them whole for cost of lost property up to some reasonable amount, and the flattened area is allowed to return to its natural condition minus humans.

    All of the above assumes people care enough to do what needs to be done. But, know what’s even scarier than a cat 7 cyclone? The law of supply and demand applied to the value of human life on an overpopulated planet that’s overshot its resource base. Contemplate that for a while.

  16. #16 Greg Laden
    November 11, 2013

    G, I agree with your basic argument.

    The weather service (the NWS anyway) does a good job of predicting and describing expected weather conditions along with a hurricane. In a way, the category system gets in the way of that as it is. A Cat 2 or 3 can still flood a region quite heavily, but if people experienced less flooding during a prior Cat 4, and then hear about the Cat 2 that is positioned in such a way to wipe out their house, that’s a problem. Bob, a Cat 2 did amazing and unprecidented (almost) flooding at the head of Buzzards bay. I remember some relatives complaining about having to be evacuated. It was only a Cat 2. When they returned to their house later, it was full of fish and sea bottom and had been completely inundated by floods, even though it was up on a hill overlooking the bay.

  17. #17 Eric Johnson
    November 11, 2013

    How do we categorize storms greater than Cat 5? That is the level of total devastation. What is beyond total devastation? Anything more than that does not provide any new, meaningful information. Adding higher categories for the sake of climate change is meaningless unless it is for political purposes. The effects on the ground are not going to change.

    The only place where there is a needed change relates to storm surge. The Saffir Simpson scale is useful regarding extent of wind damage but does not reflect the magnitude of storm surge. A weak storm can produce a large storm surge while a powerful storm may not. Hence, a storm surge category is needed and certainly more relevant than adding higher levels to the Saffir Simpson scale.

  18. #18 Greg Laden
    November 11, 2013

    I don’t regard a more effective system of letting people in on important information as political. At one level we have the problem of a given hurricane likely to affect a given population, on the other hand we have the possibility of increased storminess (generally) due to increased energy in the atmosphere and sea surfaces. That’s not political, that’s important realities.

    But yes, as I say in the post, if the SS scale is about destruction, and all TS’s above the Cat 5 threshold are the same in that respect, than the system works.

    But the argument can be made that the basic assumption of the SS scale is flawed. At one end, the lower category storms are plenty enough destructive in areas where housing is badly made, at the other end the higher strength storms that would be identified as Cat 6 or Cat 7 really do seem to be potentially more destructive.

    It is hard to say, but I’m thinking that if Haiyan was closer in overall strength to the Cat 5 threshold it may not have had the level of destruction it in fact had.

    gtl

  19. #19 Eric Johnson
    November 11, 2013

    G, I see you are in CA. I’m in FL. State building codes after the 2004 season have been strongly upgraded. New construction, especially near the coasts, are to bunker-like building. Roofs must be attached to foundations, typically through the center the cinder block walls and is then filled with cement. Windows have to be impact resistant and about double the cost of regular windows. the foundation has to be above the crown of your road. Right on the coast, most structures are elevated to let the storm surge pass under the first floor. The grocery stores are starting to do that so they can be operational after a storm.

    Hardening more than that is not cost effective. Building need to stand up to Cat 3 since up to those are the most common storm strengths. Only three Cat 5 storms have made US land fall and are so rare as to not justify the astronomical cost to build to that level.

    The simple fact of the matter is that if a big storm is coming, it’s best to evacuate. In many coastal communities, you would be cut off from civilization for weeks, maybe even months: no power, water, food or shelter and no one can get to you because of miles of debris.

  20. #20 Eric Johnson
    November 11, 2013

    Greg, you bring up some good points. There is talk about climate change making the world experience more tropical weather. That is not coming from the experts on tropical weather but from climatologists with a superficial understanding of storm mechanics. Yes more energy suggests more storms and stronger storms. But there are contrary principles at play. Climate change also increases upper level wind shear which inhibits storm formation. Climate change may lead to fewer hurricanes but more thunderstorms, which is a net benefit of climate change. Then add that to the fact that Cat 5 storms are very hard to produce. Conditions have to be maintained near perfect or they burn out fast. Hence upper level shear works against them. Being slow moving also works against them.

    Don’t let 2004 be a misleading year. Yes, more storms made landfall but there were not more storms than normal. The Bermuda High was located that year that cause more storms to be steered to land instead of curving northward over the Atlantic.

  21. #21 Greg Laden
    November 11, 2013

    The model that does the best job of predicting the frequency of tropical storms over recent decades, and also predicted this year’s North Atlantic season to reasonable accuracy, shows increasing frequency and severity of North Atlantic hurricanes and other Tropical Cyclones.

    It is not so simple as experts on tropical storms say no increase in TC’s and climatologists do. There are differences in opinion in both areas, but the “tropical storm” experts tend to be meteorologist and as a group they’ve been wrong on climate change more often than right, though they are by and large caught up these days.

    This is a question of climate change, not storm prediction. When it comes to a question of climate change, I’ll go with the climate science.

    Nobody is using 2004 to predict the future. That’s a straw man. But 2004 may be a way of helping people to visualize a future with more storms.

    If TS’s increase in frequency or severity only slowly or not at all, we are already seeing the effects of sea level rise on making their effects more severe.

    One thing I do wonder about: When Florida eventually disappears below sea level, and the Gulf of Mexico looks way different, how will that change the nature of North Atlantic storms?

  22. #22 Greg Laden
    November 11, 2013

    For those interested in donating to help with Haiyan/Yolanda, may I suggest this secular organization: http://foundationbeyondbelief.org/crisis

    But also, if you donate now don’t forget to donate later too. Often crises are forgotten about long after they are in the news but well before they are over. Entire cities and villages were flattened. This is going to take some time.

  23. #23 Steve Oregon
    November 11, 2013

    Greg,
    You cite a model that “shows increasing frequency and severity of North Atlantic hurricanes and other Tropical Cyclones”

    Observations contradict that model.

    There is no increase.

    So why cling to a model?

  24. #24 Greg Laden
    November 11, 2013

    There has been an overall increase, most likely, in TS frequency and strength over the decades but this is a difficult thing to measure. Something that happens only a few times a year and has a huge amount of intrinsic variation is hard to track.

    But the models are about the future. You see, that is the stuff that has not happened yet. It is therefore not possible to provide evidence of something that has already happened if the thing hasn’t happened yet, because we expect it to happen in the future. Unfortunately, Dr. Who and those other time travel stories are fiction!

  25. #25 Steve Oregon
    November 11, 2013

    Greg,

    Thank you the feedback.

    However, when you wrote:

    “The model that does the best job of predicting the frequency of tropical storms over recent decades, and also predicted this year’s North Atlantic season to reasonable accuracy,”

    You inferred the model had been accurate to date.

    It maters little what that climate model says when the the theory of increased strength and frequency has not occurred during the past decades of increased CO2 emissions.

    There are no real world indications at all that extreme weather is increasing. Let alone due to AGW.

    Yet you are still advising that it is. Why?

  26. #26 Russell
    November 11, 2013

    The extension of maximum storm intensity Greg proposes has long been embodied in the Modified Beaufort Scale employed by cruising sailors the world over:

    Force 0 Smoke rises vertically , sea a mirror for miles around. Hand helmsman full bottle of Demerara rum

    Force 1 Sails slack, sea surface barely undulates
    Give helmsman second bottle of Barbados rum

    Force 2 Sails begin to fill, ripples appear astern

    Offer helmsman a lime to put in second bottle of rum.

    Force 3 Bow wave appears, slack lines tighten
    Place cup of ice at helmsman’s disposal

    Force 4 Whitecaps appear, winch handle needed to trim sail
    Start adding cola to helmsman’s rum.

    Force 5 Whitecaps begin to shed spray and salt water ruins helmsman’s Cuba Libre

    Force 6 Waves lengthen, helmsman requests beer

    Force 7 Helmsman relieved after mistaking streaks of blowing foam for head on navigator’s beer

    Force 8 Waves heighten and new helmsman switches to shandy

    Force 9 Overhanging crests appear on waves, new helmsman switches to ice tea

    Force 10 Breaking waves interfere with steering. Helmsman requests black coffee

    Force 11 Violently agitated sea surface disappears beneath
    blowing foam, hand helmsman irish coffee after he agrees to set storm trysail

    Force 12 . Hurricane. Bow invisible from stern. Give all hands bottles of Demerara rum.

    Force 13 Existential Threat.
    St. Elmo’s fire ignites emergency cask of iron jack stored in bilge.

  27. […] [ /center] A proposal is afoot to add a category 6 storm to the scale. Should There be a Category 6 for Hurricanes? – Greg Laden's Blog Sign in or Register Now to […]

  28. […] is just a quick post to suggest an answer to the question posed by Greg Laden here: should we have a category 6 and above for hurricanes.  My answer is […]

  29. #29 William Hendrixson
    November 12, 2013

    I think that the existing scale is fine for mass consumption. If “Cat 5 incoming” isn’t enough to scare people into doing the right thing, why would “Cat 15″ do any better?

    But scientifically, the existing scale is nothing more than a “hi, medium, low” setting on a piece of equipment. It would seem to me that the best measurement would be to calculate the total energy of the storm and then express that in terms of area.

    I’d be curious to see the total energy of all storms of any given period of time then compared to average land and ocean temperatures over that same period. Perhaps, more accurately, only the average temperatures over land and ocean where a tropical storm has formed and traveled over…

  30. #30 adelady
    November 12, 2013

    I’d suggest a “scale” or a category that sort of lines up with the new “catastrophic” fire danger category we’re using in Australia.

    It basically amounts to, “nobody can get to you to help you during the event and we probably won’t be able to get to you after the event for a good while, maybe a long while.” Once it gets close you won’t be able to get out. Don’t wait. Get out before you can’t get out. When you see the flames or see the wind or the water is rising or the debris is flying, it’s already too late. That really applies to Category 5, but the big issue for these bigger storms – is that they’re bigger. They cover more area and any individual person or household is that much less likely to get any assistance they need in the aftermath.

    Some marketing person could turn the various concepts into something that might stick once the measurement or implications have been worked out.

  31. #31 Scott
    November 14, 2013

    I agree that adding a Cat 6 to the SS scale could make sense.. If you look at the existing scale, each category is roughly 20-25 mph increments:

    Cat 1: 74-95
    Cat 2: 96-110
    Cat 3: 111-130
    Cat 4: 131-155
    Cat 5: 156+

    Going by that pattern, maybe Cat 5 should be 156-180, and 181+ could be Cat 6.

    There have been a few storms in the past century that qualify as a Cat 6 according to what I just typed: Haiyan and Camille, and I also believe Gilbert?

    Rare, but it can happen.

Current ye@r *