The resilience of New Orleans and other vernacular.

[dave8721]

Originally Posted by galleyfox

I don’t believe New Orleans has ever had a direct strike from Category 5 winds.

Hurricane Katrina was Category 3 when it impacted New Orleans, and Category 3 winds don’t really destroy residences that are more sturdy than a mobile home.


The Florida hurricanes you’re thinking of are Category 4 and 5. In Florida, most long-time residents don’t worry about Hurricane winds below Category 4 unless they have large trees on the property.

But wind is such a low priority in a hurricane. It’s the water that usually kills you.

New Orleans barely had cat 1 winds from Katrina. Wind gusts were up to 100 mph.
Urban Miami hasn't had a direct hit from a strong hurricane since 1926. Andrew hit the southern suburbs as a Category 5 in 1992 and Irma hit the Keys in 2017. In the last 20 years Katrina, Wilma and Irma had hurricane force winds/gusts in the Miami area.
Even with Andrew in 1992 which was one of the strongest ever, older homes did fine and newer modern well built homes did ok. It was those cheap 1970-1980's crap boxes that fell apart. My house I was living in as kid went through the northern eye wall of Andrew (the worst of the worst). It was a ~late 1950s ranch style house with a low roof protected by lots of foliage and suffered very little damage, just a couple of broken windows. A house at the end of our block was reduced to the foundation. Another 2-story house on our block had the 2nd story sheered off. Was anything built well in the 1970's or 80s (other than me of course)?

[lio45]

In my area of FL, the late 1970s/early 1980s houses (I own a few) are pretty well built. Concrete block walls, roof trusses anchored in the concrete walls, concrete floors, everything pretty straight and solid.

I think it's only in the 1990s that you started to see cheaper construction appear (i.e. wood framed).

That's in central Brevard County. I'm assuming So Fla building styles would be similar.

[iheartthed]

Originally Posted by JManc

Guys. Look at a map. New Orleans is not Galveston or Miami. Same reason Houston is far less vulnerable to severe wind damage than Galveston. There are still places in New Orleans that never recovered from the flooding during Katrina and likely will never be.

New Orleans doesn't seem far enough inland to say that this isn't a threat (same for parts of Houston for that matter). A category 5 coming in at the right angle could probably maintain itself as a cat 4 - 5 when reaching the city of New Orleans.

[The North One]

Originally Posted by ardecila

That's what they said after Hurricane Betsy in the 60s. The levees they built back then failed in Katrina, after only 40 years.

New Orleans is built on thousands of feet of spongey silt that is constantly sinking due to natural and man-made factors, so levees of a certain height become less effective every year. That's before you factor in general sea-level rise, and an increase in the severity and height of hurricane storm surges due to climate change and the loss of natural barrier wetlands.

I'm not sure an engineering solution to this problem is even possible, and it would be orders of magnitude more than what the Army Corps has built post-Katrina.

Yeah, New Orleans is clearly a sitting duck with limited time. Anybody who thinks otherwise is delusional.

Sucks because it's probably the most unique city in the United States. A gem of a place.

I feel like if New Orleans didn't have the worst geography in the world it would have been a much more prominent city today. It would be like what Houston is but with a great urban core.

[JManc]

Originally Posted by iheartthed

New Orleans doesn't seem far enough inland to say that this isn't a threat (same for parts of Houston for that matter). A category 5 coming in at the right angle could probably maintain itself as a cat 4 - 5 when reaching the city of New Orleans.

They are far enough that a Cat 5 would probably reduced to a Cat 3 (or less) by the time they drifted that far inland. Hurricanes lose steam the moment they hit land. It's usually those directly on the coasts that are the most vulnerable to the full brunt but everyone around still has the flooding and gusts. Our neighborhood was under 9' of water during Harvey. Galveston is 60 miles away.

[iheartthed]

Originally Posted by JManc

They are far enough that a Cat 5 would probably reduced to a Cat 3 (or less) by the time they drifted that far inland. Hurricanes lose steam the moment they hit land. It's usually those directly on the coasts that are the most vulnerable to the full brunt but everyone around still has the flooding and gusts.

If a storm traveled west and parallel to the coast into the bay it could hit New Orleans from a water route. It's a pretty narrow path, though, so the probability of it happening is likely low. But it's not zero.

I'm also not so sure that Miami has a much greater risk of a category 5. A storm also has to walk a relatively narrow path to hit Miami from an all or mostly water route due to the Bahamas and Cuba.

[SlidellWx]

Here is a listing of the strongest wind speeds recorded in New Orleans from recent past hurricanes.

Hurricane Katrina had a peak gust reported at NASA Michoud in New Orleans East of 107 knots or 123 mph. The anemometer was located 12.2 meters/40 feet above ground level. Wind damage in the city was consistent with a category 3 hurricane.

Hurricane Ida had a peak gust reported at WVUE television station of 98 knots or 113 mph. The anemometer was located 18 meters/59 feet above ground level. Wind damage in the city was consistent with a category 2 hurricane.

Hurricane Zeta had a peak gust reported at New Canal Lighthouse of 85 knots or 98 mph. The anemometer was located at the standard 10 meter/33 feet level. Wind damage in the city was consistent with a cat 1 hurricane.

Although wind reporting equipment was not as reliable in 1965, Hurricane Betsy had a peak wind reported in New Orleans of 95 knots or 110 mph.

Data prior to that in terms of wind speed measurements are far less reliable although several strong hurricanes impacted the city.

The city has yet to see wind speeds equivalent to a category 4 or higher hurricane, which is pretty amazing given it is over 300 years old.