What is JB's rant about- Is a Cat 3 now just 110 mph?

[DanKellFla]

MWatkins, I agree with you.
Cyclone1, Yes, they are that oblivious. Here is an example:
I have a collegue that INSISTS that Wilma was a Cat 3 storm because "It looked that way." After showing him all the reports and the post season reports showing otherwise, he still refuses to believe me. My point is not to prove that I am right, but to educate him just how powerful a Cat 1 or Cat 2 storm can be. And, that gusts also play a role and can vary greatly from storm to storm. I was trying to get my collegue to take the NHCs data seriously and not rely on a "gut feeling" because the next storm that comes through, he will have his expectations totally out of wack. In my discussions with others, most think that every Cat 1 storm is the same as every other Cat 1 storm. I quickly loose people when I start talking about wind diameters, forward speed and other storm specific information. For this reason, even though the intensity estimate was "blown" as Derek points out, I still think that particular warning got the essence of the danger correct. I see those warnings as a tool for the general public, not a scientific piece of data. If people really paid attention to the details of the storm, those kinds of warnings would be uncessary.
Personally, I listent to the ProMets around here before a storm.

[Cyclone1]

Yeah, I guess you're right.

[Typhoon Hunter]

In the Wpac difference agencies have different scales. The Japanese use the following scale:

Tropical Depression 33kts

Typhoon 34 - 63kts

Strong Typhoon 64 - 84kts

Intense Typhoon 85 - 104kts

Violent Typhoon 105+kts

Source - http://agora.ex.nii.ac.jp/digital-typhoon/help/unit.html.en


Hong Kong came up with a new classifications this year (10 minute wind speeds):

Tropical Depression up to 33kts

Tropical Storm 34 - 47kts

Severe Tropical Storm 48 - 63kts

Typhoon 64 - 80kts

Severe Typhoon* 81 - 99kts

Super Typhoon* 100+kts

Source http://www.weather.gov.hk/informtc/class.htm

*classifcations added in 2009.

[docjoe]

let me preface this by saying i am a rank amateur with no scientific knowledge of hurricanes other than just an avid interest. I do have the experience of taking the brunt of Ivan (though not the eyewall) and the eye of Dennis headon. Thus I do have some familiarity with the destruction these storms can cause. i have thougoht for some time that a scoring system could be used. At least in my mind it would clearly give a decent idea of what to expect. I would assign a score of 1-5 for expected wind, rain, and surge. These parameters would vary for a given area. For a given storm maybe a threat from wind would be a 3, from surge maybe a 4 and from rain maybe a 2. This would give a score of 9 out of 15. It would give some type of overall rating yet each major component would have an easily recognizable ranking that could be unique for a given area(for example the surge threat from Katrina would have been a 5 however if the same storm hit elsewhere the surge score may have only been 3)...i am sure there are reasons this would not work that i have not thought of but it is a start

docjoe

[jinftl]

You are right, I am asking people to change their behavior. Actually, I am asking that people change the thought process that they undergo when a storm is approaching. That in turn would modify behavior. I think behavior modification is in order. What if Ike had struck with a 20' surge on Galveston Island like was forecast? How many of the tens of thousands who wouldn't leave would have benefited from a little behavior modification. What would that additional 10 feet of water have done?

I am also asking people to listen to those who are the experts...the NHC and their forecasts and emergency management and local officials. This is what they do....what makes their forecasts and recommendations/orders less believable than an individual who is not a meteorologist, knows very little about storms, and is basing their views on pass hits or misses and assuming repeats of those making their own 'stormcasts'?

If all else fails, I am asking people to look around. What are the majority of your neighbors doing? Are they leaving? Are tv news crews reporting from your neighborhood? That is another tip off that you probably should get out. Bottom line, people who are in the surge zone can either hold their ground and refuse to budge...and maybe luck out most of the time....but they will lose that gamble at some point. Take a cue from the animals in nature....they know to flee or seek shelter before a storm. Only humans don't want to modify their behavior in order to survive. Don't forget, Mother Nature has ways of modifying behavior too....ask katrina survivors if they will stay for the next threat.

A lot of the confusions and misperceptions the public has could be easily overcome by doing one simple thing...listen to your local emergency management officials.

Two mistakes. One, you're asking people to change their behavior and two, you're asking people to put trust in others who may or may not be qualified. Apparently many thought the mayor of Galveston was a qualified emergency management official they should listen too.

Again I think it's important to stick to the idea that we need to convey information to people who really aren't interested in it but will react if it's presented in a simple enough fashion. We stumbled upon this system when categories were introduced and now I think it should be a simple enough task to quietly change how those number are derived so people react based on the real danger as perceived by hurricane forecasters.

[meteorologyman]

docjoe had an excellant idea on how storm surge and rain should be scaled. I just figured out why surge scale may not work.

For example like Katrina: Cat 3 storm with Cat4 (17ft) surge. New orleans can only withstand a minimum cat3 surge, so people know in that area needs to evacuate because surge is greater than what the area can hold.

Now lets say Cat4 surge head straight for Pensacola Fl. A 17 ft surge crashing into pensacola would not do much because the elevation is 120ft above sea level that would take a Category 15 hurricane surge. However 1 mile west or east the elevation could drop to only being 0-1 ft above sea level. Land height changes so extreme from one area to the next that there is no telling if it will see a CAT5 destruction or no destruction just a couple miles change of course can change the outcome of how much damage would cause for better or worse.

[MGC]

Sections of downtown Pensacola saw significant surge...so, I don't know what you are talking about. In fact quite a large swath of Florida coast line saw considerable surge damage from Ivan. Had Ivan followed a similar path as Katrina, Ivan would hold the title as most destructive hurricane in American history.....MGC

[vbhoutex]

docjoe had an excellant idea on how storm surge and rain should be scaled. I just figured out why surge scale may not work.

For example like Katrina: Cat 3 storm with Cat4 (17ft) surge. New orleans can only withstand a minimum cat3 surge, so people know in that area needs to evacuate because surge is greater than what the area can hold.

Now lets say Cat4 surge head straight for Pensacola Fl. A 17 ft surge crashing into pensacola would not do much because the elevation is 120ft above sea level that would take a Category 15 hurricane surge. However 1 mile west or east the elevation could drop to only being 0-1 ft above sea level. Land height changes so extreme from one area to the next that there is no telling if it will see a CAT5 destruction or no destruction just a couple miles change of course can change the outcome of how much damage would cause for better or worse.

????????????Where did you come up with that? Since I grew up in the Pensacola area, I would have to see some proof of that to believe it. BTW, the surge from Ivan in upper Pensacola Bay(Escambia Bay) at the I-10 bridge was on the order of 15+ feet and destroyed the I-10 bridge. You really need to check your facts and figures before posting.

[wxman57]

Pensacola regional airport, just 1 miles from the western shore of the bay is 38 meters, or over 120 ft above above MSL. Downtown, just west of the airport, is a bit lower elevation. But there is a considerable rise in elevation just inland. So there is a sharp elevation increase just inland in Pensacola. And due to a coastal shoaling factor multiplier of 0.6 (vs. 1.8 for MS), the same hurricane hitting MS and Pensacola would produce 3 times the surge height in MS as it would in Pensacola.

Oh, and there's no such thing as a "Cat 4 surge" or "Cat 5 surge", as I've said many times. The SS category plays only a very minor role in surge generation compared to radius of max winds, angle of approach, and coastal bathymetry.

[jinftl]

All of these alternative scales of measuring surge are based on the assumption that we know the exact location of landfall in advance of the storm. That is impossible to know. Even a 50-mile margin of error could mean any one point is going to be on the west side of the eyewall or the east side of the eye wall...that could mean all the world of difference in surge impacts. The process of storm preparation and evacuation has to be done with that understanding...that the worst case scenario may not happen due to normal margins of error 24 or 48 hours out. But the likelihood of that worst case is great enough that full preparation is needed. People shouldn't be angry if they 'evacuate for nothing'...they should be thanking their lucky stars.

For example....what if Katrina had hit 75 miles west of where she did....or if Rita hit 75 miles west of where she did. Areas of impact would have been expanded/different...but those areas were as likely to see landfall as the actual locations that did when it was time to evacuate (24-48 hours out) given the normal margin of error.

[vbhoutex]

Pensacola regional airport, just 1 miles from the western shore of the bay is 38 meters, or over 120 ft above above MSL. Downtown, just west of the airport, is a bit lower elevation. But there is a considerable rise in elevation just inland. So there is a sharp elevation increase just inland in Pensacola. And due to a coastal shoaling factor multiplier of 0.6 (vs. 1.8 for MS), the same hurricane hitting MS and Pensacola would produce 3 times the surge height in MS as it would in Pensacola.

Oh, and there's no such thing as a "Cat 4 surge" or "Cat 5 surge", as I've said many times. The SS category plays only a very minor role in surge generation compared to radius of max winds, angle of approach, and coastal bathymetry.

Thanks for clarification on this Chris. I did not realize the rise in elevation was that significant. Much of the downtown area of P'cola is not more than 15 feet msl if that, but there is a significant rise that begins about a mile inland. In fact it begins near a school I went to in my elementary years.
The problem with the previous statement was that it made it sound like the whole area was at 120 msl and that is not the case by any measurement.