Revising the SS scale

[f5]

i keep reading articles that some are sugessting that thier needs to be a category 6 beacuse Katrina,Rita,Wilma reached an insane 175 mph.does anyone here think there needs to be a category 6 added i don't beacuse once the winds get above 155 you can't tell the difference between structures destroyed by 165 mph winds instead of 180 mph

[WindRunner]

No, there is no need for a category 6, as a category six would probably end up starting around 180 anyway. However, the entire scale itself and the basis for it needs to be reworked; in other words, we need a new scale for these storms. Something that still ranks them on something easy for the public to understand and act on, but is better at getting at the damage potential to the public. Unfortunately, the data needed for such a scale would make it hard to retrofit 35+ years back, but we must consider that the need for public safety, and something needs to be done to improve the public awareness.

[x-y-no]

I don't see any reason to add a category 6 to Saffir-Simpson. Instead, I'd like to see some new classification system which takes into account the overall size of the windfield as well as the peak sustained wind. I don't think the SS scale adequately indicates the destructiveness of a storm.

[vbhoutex]

I may be off base here, but I see some of the problem with the SS scale, if there really is one, being the fact that the winds that are often measured, don't actually mix down to the surface sometimes(it seems many times if we take into account actual measured winds) so many think that they are getting CAT3 winds when they may only be getting CAT2 or maybe lower winds. In actuality, maybe it is fine just the way it is since that would put it on the "conservative" side.

[wxman57]

I think that one major problem is that the SS scale only considers the absolute peak winds (over a marine environment) in a hurricane. What is NOT taken into consideration is the expanse of damaging winds. In many hurricanes, the peak winds occur only in very small regions of the storm, and then, only over the water. In most cases, when these winds reach land, the frictional effects reduce the speed by as much as 20-30 mph (a category or two).

Therefore, most Cat 1 or 2 hurricanes which strike land do not really produce any widespread 75+ mph winds inland. Many who have gone through a Cat 1-2 hurricane only experienced a TS. But wind force increases exponentially with the wind speed, so a true 75 mph wind is quite strong enough to cause considerable structural damage.

Katrina struck Mississippi as a Cat 3 hurricane with 115-120 mph winds in a small area east of the center. But it was the huge expanse of 85-110 mph winds that generated the tremendous storm surge along the MS coast. And this huge area of high winds spread inland such that very many people actually saw sustained 75-95 mph winds, a rarity for most hurricanes.

So to call a hurricane a Cat 3 really says nothing about the true structure of a hurricane. How expansive are those Cat 3 winds? How large is the 75+ mph wind field? The SS scale doesn't address those issues, it concentrates on that one peak wind in the storm.

[Zackiedawg]

One possibility might be to maintain the current scale for the NHC to use internally as a means of labeling storms, while developing a new system to use with the public who often do not understand the many subtle variables which can make a particular storm worse than its 'category' rating might suggest.

A new 'risk' rating of a storm can take into consideration the likely damage from maximum winds, damage from storm surge, damage from sustained winds, the impact of a slow moving storm delivering sustained winds for a linger period of time, the impact of a huge storm spreading sustained hurricane winds over a larger area and for a longer period of time, the aftermath expectation of power outages, communication problems, flooding issues, etc., and can even take into consideration a particular area's preparation for a storm (for example, a weak storm hitting New England may deliver more damage and cause more infrastructure problems than a stronger storm hitting South Florida which has stronger building codes and experience dealing with such storms).

With a revised civilian risk rating, people might be more prone to take storms seriously despite the lower 'category' rating the storm receives on the SS scale. Wilma may have received a higher risk rating due to her increased southern windspeeds from fast forward motion, relatively low loss of strength over land due to fast speed, size of the storm which could spread damage to a very wide area, and high risk of long-term power outages due to South Florida's archaic above-ground power lines and damage within the past year from other storms. A storm like Frances might have gotten a higher risk rating due to her immensity, and the fact that she moved so slowly that her minimal hurricane and tropical storm winds were felt for days causing fatigue damage to trees and structures.

Meanwhile, a storm like Charley or Andrew might be better handled as the relatively narrow field of impact, though incredibly intense, might prompt less widespread evacuation scares, easing the evac routes for those who need them instead of crowding the 3 north-south routes out of the state with the entire population of the Florida coast. The risk ratings could be listed very high in the impact zone, but quickly lowered in surrounding areas outside of the eye wall. Maybe this would allow more last-minute decision-making possible for those not sure if they will be struck, so they can get out if any last-minute directional changes occur, but stay put if the risk is diverted elsewhere.

The problem isn't with those who follow storms...we all know what to expect in a given storm because we check up on it, read all the reports, follow trends, current steering patterns, and temperature trends in the storm's path. The problem is with the general public whose knowledge of a coming storm's danger is limited to the SS category rating, or the panic-inducing wind-blown raincoat-wearing reporters' blather. Meaning the public is often either filled with a false sense of security due to a low SS category number, or filled with a false sense of dread and fear due to the panic of uninformed newsfolks looking to drum up ratings. Meaning they are either surprised when the little Cat 2 delivers a catastrophic blow, or suffer from 'cry wolf' syndrome after hyped storms failed to live up to their expectations and decide not to leave for the next one.