New TC intensity criteria needed.

[MGC]

In absence of a real tropical cyclone to track in the Atlantic basin, I've been reading up on tropical cyclones of historical proportion. I've come to the conclusion that new creteria in needed for rating hurricanes. The Saffier-Simpson rating is too simplistic in its method of rating hurricane intensity. As you know, the current system uses maxium sustained winds as the primary criteria. For example, a category 5 hurricane has sustained winds in excess of 155 MPH. But, are all 155 mph hurricanes equal? For that matter are all tropical storms equal? Take for example hurricanes Andrew and Floyd. Both hurricanes were category 5 storms. However, Floyd was an much larger hurricane in its wind field, nearly twice as big. Had Floyd stuck south Florida at the same trajectory and wind intensity the damage zone would have been far greater. Another example could be tropical storm Isidore of 2002 and tropical storm Barry of 2001. Both tropical storms had nearly identical central pressures of around 990mb at landfall. Isidore was a much larger tropical storm and caused considerable surge flooding. As such, the scope of the storm should be taken into consideration when assigning intensity rating to tropical cyclones. A tropical cyclone that will affect a significantly larger area than an average storm should be given consideration for a higher rating......MGC

[HurricaneBill]

In absence of a real tropical cyclone to track in the Atlantic basin, I've been reading up on tropical cyclones of historical proportion. I've come to the conclusion that new creteria in needed for rating hurricanes. The Saffier-Simpson rating is too simplistic in its method of rating hurricane intensity. As you know, the current system uses maxium sustained winds as the primary criteria. For example, a category 5 hurricane has sustained winds in excess of 155 MPH. But, are all 155 mph hurricanes equal? For that matter are all tropical storms equal? Take for example hurricanes Andrew and Floyd. Both hurricanes were category 5 storms. However, Floyd was an much larger hurricane in its wind field, nearly twice as big. Had Floyd stuck south Florida at the same trajectory and wind intensity the damage zone would have been far greater. Another example could be tropical storm Isidore of 2002 and tropical storm Barry of 2001. Both tropical storms had nearly identical central pressures of around 990mb at landfall. Isidore was a much larger tropical storm and caused considerable surge flooding. As such, the scope of the storm should be taken into consideration when assigning intensity rating to tropical cyclones. A tropical cyclone that will affect a significantly larger area than an average storm should be given consideration for a higher rating......MGC

Floyd never reached Category 5. Maximum sustained winds were 155 mph. 1 mph short of Category 5 status.

[HURAKAN]

In absence of a real tropical cyclone to track in the Atlantic basin, I've been reading up on tropical cyclones of historical proportion. I've come to the conclusion that new creteria in needed for rating hurricanes. The Saffier-Simpson rating is too simplistic in its method of rating hurricane intensity. As you know, the current system uses maxium sustained winds as the primary criteria. For example, a category 5 hurricane has sustained winds in excess of 155 MPH. But, are all 155 mph hurricanes equal? For that matter are all tropical storms equal? Take for example hurricanes Andrew and Floyd. Both hurricanes were category 5 storms. However, Floyd was an much larger hurricane in its wind field, nearly twice as big. Had Floyd stuck south Florida at the same trajectory and wind intensity the damage zone would have been far greater. Another example could be tropical storm Isidore of 2002 and tropical storm Barry of 2001. Both tropical storms had nearly identical central pressures of around 990mb at landfall. Isidore was a much larger tropical storm and caused considerable surge flooding. As such, the scope of the storm should be taken into consideration when assigning intensity rating to tropical cyclones. A tropical cyclone that will affect a significantly larger area than an average storm should be given consideration for a higher rating......MGC

As I know Hurricane Floyd was not a Cat. 5, with winds of 155 mph it only qualifies as a Cat. 4. The Saffir-Simpson Scale I believe is fair, I don't think changes should be made. But I believe the Fujita Scale should be replaced by another method more convenient to qualify a tornado. A tornado should be qualified by its intensity and not by the destruction it left behind. In conclusion, the Saffir-Simpson Scale for me a pretty good and understandable way to qualify a tropical system

[MGC]

Floyd was far more a hurricane than Andrew. I'd rather go though Andrew than Floyd. Floyd was twice as big. Wind intensity is just to vague of a qualifier.....MGC

[MWatkins]

In absence of a real tropical cyclone to track in the Atlantic basin, I've been reading up on tropical cyclones of historical proportion. I've come to the conclusion that new creteria in needed for rating hurricanes. The Saffier-Simpson rating is too simplistic in its method of rating hurricane intensity. As you know, the current system uses maxium sustained winds as the primary criteria. For example, a category 5 hurricane has sustained winds in excess of 155 MPH. But, are all 155 mph hurricanes equal? For that matter are all tropical storms equal? Take for example hurricanes Andrew and Floyd. Both hurricanes were category 5 storms. However, Floyd was an much larger hurricane in its wind field, nearly twice as big. Had Floyd stuck south Florida at the same trajectory and wind intensity the damage zone would have been far greater. Another example could be tropical storm Isidore of 2002 and tropical storm Barry of 2001. Both tropical storms had nearly identical central pressures of around 990mb at landfall. Isidore was a much larger tropical storm and caused considerable surge flooding. As such, the scope of the storm should be taken into consideration when assigning intensity rating to tropical cyclones. A tropical cyclone that will affect a significantly larger area than an average storm should be given consideration for a higher rating......MGC

A couple of considerations.

1. Why? Damage potential and intensity are two completely different measurements. Intensity scales such as the Safir Simpson scale and the Fujita Scale apply only to the maximum winds expected...so that the public can be alerted to the potential damage if a storm affects their paticular location.

In terms of area of impact...this is covered well in the public advisories and by local media. So...the rating system you propose would be great for post analysis...but has little if any application in the real world in terms of public awareness.

As far as post analysis goes...normalized damage amounts in terms of dollars are as absolute as you can get...and significant events are always measured this way. So I don't see the gain by changing the classification scheme.

2. Quite honestly...if we start rating hurricanes along those lines...wind radius...pressure background differences and issues like concentric eyewall strutures get introduced to the mix...and these variables are almost impossible to measure with any accuracy. Most of these factors are a guess by forecasters...and are by no means absolute.

Plus...you may tick off the public when they are expecting (for example) a category 10 storm (Opal) and they get only a Category 2.

Way too confusing...impossible to measure with any current technology IMHO.

The current scale works...and is consistent with how we measue other atmospheric systems. Until our ability improves so these items can be forecast and measured with significantly better skill...I must respectfully disagree with the need for a new scale.

MW

[HURAKAN]

Floyd was far more a hurricane than Andrew. I'd rather go though Andrew than Floyd. Floyd was twice as big. Wind intensity is just to vague of a qualifier.....MGC

That's your opinion and you sure know which opinion is the one that's valid.

[FWBHurricane]

Actually knowing the range of the winds would help because it would show where the worst winds of the storms are and it can show people if they live in a dangerous area or not.

[FWBHurricane]

It would also help with knowing if you should evacuate or not...but thinking about it you have to consider storm surge near you too.

[rainstorm]

Floyd was far more a hurricane than Andrew. I'd rather go though Andrew than Floyd. Floyd was twice as big. Wind intensity is just to vague of a qualifier.....MGC

andrew is only a cat5 based on revisionism 10 years later. had floyd made landfall at peak intensity it would have caused much more damage than andrew.

[hurricanemike]

Floyd was a Cat 5 @ 135 kt

[senorpepr]

Floyd was a Cat 5 @ 135 kt

Actually 135kt would put it at the top end of cat 4.

Maximum sustained winds increased from 95 knots to 135 knots, and the central pressure fell about 40 mb from early on the 12th to early on the 13th. From 0600 to 1800 on the 13th, Floyd was at the top end of category four intensity on the Saffir/Simpson Hurricane Scale.

http://www.nhc.noaa.gov/1999floyd.html

[hurricanemike]

135 kt = 156 mph

I cant help they round down. I cant use Unisys to back me up anymore because they changed 135 kt to Cat 4.

[The Dark Knight]

Does it really round up that high?????........

[hurricanemike]

135 * 1.152 = 155.52, 0.5+, round up the next whole #

[senorpepr]

135 * 1.152 = 155.52, 0.5+, round up the next whole #

Don't get me wrong, in my opinion it's cat 5. I never really cared for the NHC's guidance in that area.

As for 135kt = 155.52mph, the NHC uses 1.15 as the converter instead of 1.152. I know... it's only 2 thousandths, but it's enough.

135 = 1.152 = 155.52 = Cat 5
135 = 1.15 = 155.25 = Cat 4

[HUC]

Perhaps they can add a rain criteria to the wind speed(cat:1 in wind+cat 3 in rain??).
I said that,becaused,frequently,people that suffered a cat 4(like Hugo here in Guadeloupe)think when there is a threath of a cat1(like Marilyn,in Guadeloupe):"well,after Hugo,this is a gentle storm"...And in fact,they don't preprare with accuracy for the cat1
And Marilyn was here a real desaster............

[hurricanefloyd5]

i should be called a cat.5 hurricane because if i had hit here in centreal florida where i live i would have cause cat.5 damage here so yes i think i should have a cat.5 storm. coments are welcome!!!!!!!!!!!!!!!!!!!

[hurricanefloyd5]

i mean if i hit here in orlando or anywhere that strong then yes a cat.5 sounds reasonable to me but u also have to remember that i had 155mph winds 1mph shy away from from being a cat.5 so again yes i think i should have been called a cat.5 hurricane...........

[isobar]

The concept sounds to me somewhat like the Northeast Snowfall Impact Scale (NESIS) that Kocin/Uccellini developed. (except that it's a damage scale) But it accounts for area and population affected.

I can understand your point that if Floyd had taken the same path as Andrew, damage would have been far worse and more widespread, even though winds were a fraction shy of cat 5.
However I believe our current scale and warning system are the best we've got based the complexities and fluctuating nature of hurricanes and our current technology.