What is everyone's worst case hurricane scenario? (Ortt pg3)

[wxman57]

As has been mentioned, you need to define "worst case" more. For any location, there is a probable worst case and a possible worst case.

For the possible worst case, you have to assume a Katrina, Rita, Gilber, Carla, Allen-sized hurricane at peak intensity moving slowly into the coast from the proper angle to produce the maximum storm surge.

Charley of 2004 wouldn't be a worst-case by any means for south Florida as it was just too small and moving too quickly. Katrina with 6-8 hours more to deepen before hitting Miami would produce stronger winds than were observed with Katrina, but it would by no means be a worst-case for Miami as a possible small Cat 2 hurricane. For the person who thinks he/she experienced a worst-case scenario in LaPlace, LA with Katrina, you're not even close. Katrina as a full-sized Cat 5 striking just west or you would be your worst case. That would cover your area with Cat 3 winds and a much greater and faster-rising surge.

So think Cat 5 with hurricane force winds extending at least 100nm from the center and Cat 5 winds all around the core as a worst-case POSSIBLE hurricane at landfall.

As for worst PROBABLE scenario, you have to look at climatology to estimate how big and powerful a hurricane could reach your latitude. A Katrina, Rita, Gilbert, or Carla at max size/intensity isn't likely to hit New York, for example, but such a hurricane could very well strike the southeast U.S. or Gulf coast just about anywhere.

Worst case also involves lead time for warnings/evacuations. A rapidly intensifying hurricane at night (think Opal) that hits as a large Cat 5 with short notice would be a worst case as people would have less time or no time to evacuate. That would lead to a greater loss of life.

Worst case would also have to take into consideration the impact to our nation's economy. Taking out a large chunk of oil refininig capacity in the Houston Galveston area could result in gas prices skyrocketing to perhaps $10/gallon or more.

So think about those factors when you consider your worst-case scenario.

[P.K.]

Well sticking just to North Atlantic hurricanes I'd say something along the lines of Mitch in 1998. Globally I'd say a strong supercyclonic storm into Bangladesh.

If I'm allowed to just use hurricane force winds for my area I'd say a deep low moving south down the North Sea with the resultant storm surge over topping the Thames Barrier but that would have to be some storm surge! The Netherlands would also be under threat in that case.

[HurricaneBill]

Well sticking just to North Atlantic hurricanes I'd say something along the lines of Mitch in 1998. Globally I'd say a strong supercyclonic storm into Bangladesh.

If I'm allowed to just use hurricane force winds for my area I'd say a deep low moving south down the North Sea with the resultant storm surge over topping the Thames Barrier but that would have to be some storm surge! The Netherlands would also be under threat in that case.

Would a repeat of the 1953 storm be a worst-case scenario?

[Yarrah]

Well sticking just to North Atlantic hurricanes I'd say something along the lines of Mitch in 1998. Globally I'd say a strong supercyclonic storm into Bangladesh.

If I'm allowed to just use hurricane force winds for my area I'd say a deep low moving south down the North Sea with the resultant storm surge over topping the Thames Barrier but that would have to be some storm surge! The Netherlands would also be under threat in that case.

Would a repeat of the 1953 storm be a worst-case scenario?

No, that won't happen again in the near future, because the flood protection systems are massive in the regions affected by the storm in 1953. Worst case scenario here would be broken levee at a certain point near the city of Rotterdam. If this would happen (it is estimated that a storm equivalent to a category 2 hurricane could do the trick), a large portion of the western part of my country would flood. Studies show that this would result in at least 71.000 deaths.

[P.K.]

I did say it was unlikely. The Netherlands has a very extensive flood barrier system and we have the Thames Barrier. But with sea level rises (Eustatic and Isostatic changes as well as the sea expanding as it warms) the effectiveness of these barriers will drop. That is the worst thing I can see happening in the UK from storm surge as London is the economic capital and was saved in a large part I believe by the flooding further downstream in 1953 due to poor maintenance after the war.

[MGC]

Hurricane Floyd does not recurve up the EC but remains on a westerly course coming ashore on Miami Beach. The coast up to West Palm is destroyed like Katrina did Mississippi. Floyd's nearly Cat-5 winds produce Andrew like destruction in Dade and Broward Counties. Floyd crosses the Florida peninsula and intensifies in the GOM back to a Cat-4/5. Floyd follows the loop current towards the Louisiana coast but turns back towards the west before landfall in Louisiana. Floyd destroys the oil rigs in the gulf south of Louisiana before making landfall near Galveston. A massive surge floods the Galveston Bay area and the strong winds cause massive wind damage.....MGC

[LaPlaceFF]

AFor the person who thinks he/she experienced a worst-case scenario in LaPlace, LA with Katrina, you're not even close.

Well, maybe not with the winds and such. But as effecting everything else economically and myself mentally it was a worst case scenario for me. It's amazing what a Cat 2/3 (I'm not sure how Katrina was classified) has done to here in LaPlace (and we weren't hit directly by the eye)

[wxmann_91]

I know Derek will say NYC and I will agree with him.

Nonetheless, the FL Keys, NJ coastline, New England, are all very vulenerable. A large strong storm rolling up Naragansett (sp?) Bay would devastate Providence, RI. Certainly those do not even come close to matching the type of devastation one would see if a cane rolled into NYC.

Miami would lead to high damages but it is certainly not the worst case. Neither is Galveston/Houston.

EDIT: Oh yeah, for intensive purposes, let's say this is NOT a CV storm and rapidly intensifies off the Outer Banks catching everyone off guard. And, let's add a phasing with a negatively tilted trough over Quebec and northern New England to create havoc over those areas as well. This and of course the upper low stalls and creates flooding rains over the Northeast, and finally, to top it off, strong southerly winds created by a pressure gradient with a strong high to the east creates coastal flooding issues for those who already have been devastated by the hurricane.

[Blown Away]

Major hurricane landfall with the center moving in over West Palm Beach. That NE quadrant would push surge water into the Jupiter Inlet. I've seen what Cat 1,2 sustained winds with Cat 3 gusts can do, it's the sustained Cat 3 and higher winds that would devastating.

[Derek Ortt]

I know Derek will say NYC and I will agree with him.

You'll find out later this week

[Chacor]

I sometimes wonder what would happen if a supertyphoon threatened Singapore. Given how the government reportedly played Tropical Storm Vamei down as a "low pressure system" in 2001 despite JMA reports of 45 kt winds (and JTWC reports of 75 kt!)...

[cajungal]

Worst scerario for my area, would be a hurricane of Katrina's size and intensity either moving directly over my parish (Terrebonne) or just to the west near Morgan City. Andrew hit around Morgan City, an my town had winds sustained at just over 100 mph with some higher gusts. Then, we would be on the dirty side of the storm. Since Katrina hit just east of Grand Isle, my area got winds around the 75-80 mph range. Just mostly roof damage and lots of trees down.

[Derek Ortt]

Storms like Wilma and Katrina existed in very different atmospheric environments where air around the periphery of the storms were moist and allowed for rapid development of thunderstorms in feeder bands. These bands feed the core, but eventually consolidate to form rings and eyewalls themselves, starving the core and weakening the storm--hence frequent eyewall replacement cycles. Isabel had virtually no such bands--just a donut of fury--hence the long annular appearance and sustained intensity of 130kts or more for almost 4 days. On September 14th, the eye had actually increased in diameter instead of the typical shrinking we see with intense storms. This was all due to the storms structure and the environment around the core.

I am giving a talk in Boulder, Colorado next month that shows that the opposite is true. But that is a little off topic for this thread

[SouthFloridawx]

Storms like Wilma and Katrina existed in very different atmospheric environments where air around the periphery of the storms were moist and allowed for rapid development of thunderstorms in feeder bands. These bands feed the core, but eventually consolidate to form rings and eyewalls themselves, starving the core and weakening the storm--hence frequent eyewall replacement cycles. Isabel had virtually no such bands--just a donut of fury--hence the long annular appearance and sustained intensity of 130kts or more for almost 4 days. On September 14th, the eye had actually increased in diameter instead of the typical shrinking we see with intense storms. This was all due to the storms structure and the environment around the core.

I am giving a talk in Boulder, Colorado next month that shows that the opposite is true. But that is a little off topic for this thread

I would be interested seeing that discussion...

You mean that feederbands feed the core, correct? It would not suprise me if this was in fact false. I would not be suprised if the low level flow/convergent air masses, coupled with the warm sst's and also a moist environment were more responsible than feederbands for the intensification of systesms.

Not that I'm an in any way shape or form an expert but, IMO only... I would say that an different explination may be the case for holding feeder bands responsible for eye-wall replacement cycle.

Anyway... let me know if get that video available.

[Derek Ortt]

or one could come to my Master's Thesis defense sometime later this year

[wxman57]

AFor the person who thinks he/she experienced a worst-case scenario in LaPlace, LA with Katrina, you're not even close.

Well, maybe not with the winds and such. But as effecting everything else economically and myself mentally it was a worst case scenario for me. It's amazing what a Cat 2/3 (I'm not sure how Katrina was classified) has done to here in LaPlace (and we weren't hit directly by the eye)

No, it wasn't a worst case. It was bad, but it could have been much, much worse had Katrina moved inland west of New Orleans. LaPlace only received tropical storm-force widns west of Lake Pontchartrain. You didn't even see 1-minute hurricnae-force winds there, though gusts were above hurricane force. You reall lucked out with Katrina.

Here's the post-storm wind analysis over SE LA:

http://www.aoml.noaa.gov/hrd/Storm_page ... ll_mph.pdf

[LaPlaceFF]

That is so true. But what I am seeing what is happening here and that storm coming more westward. I SHUDDER to think what could've happened. I heard experts in my area say the storm had to come at least 5 MILES more west for LaPlace to recieve flooding.

Yes I have it bad.....but it VERY EASILY could've been worse

[Aslkahuna]

Actually, the 75kt winds in Vamei were REPORTED winds from US Navy vessels in the area which also had radar coverage of the system. However, Vamei was so small that Singapore proper did not get high winds from it. A Long Island Express type system that accelerates to a fast forward motion as it passes Hatteras could be a nasty situation-especially if it came in a bit further west like near NYC.

Steve

[Chacor]

Actually, the 75kt winds in Vamei were REPORTED winds from US Navy vessels in the area which also had radar coverage of the system. However, Vamei was so small that Singapore proper did not get high winds from it.

The government here reported 80 km/h winds in the papers, if I remember correctly. That's quite a way off from 75 kt. To be fair, we were on the southern side of the storm, too.

[timNms]

A Katrina sized storm with Cat 5 winds hitting the same area that Katrina hit. It would wipe the map of MS and LA.