Dooms day hurricane Miami...(My thinking)

[Derek Ortt]

I saw the damage in Arcadia and that is what cat 2 winds should do. The codes were AWFUL

[terstorm1012]

Skyscrapers falling over?

No offense, but they are better engineered than that. They look flimsy, but they're really not, otherwise the fatigue of constant wind blowing over decades (in the case of NYC) would have weakenend and toppled them, and the older buildings there have seen some gusts from the '38 cane, Gloria, Bob, and Hazel, to name a few.

I'm not an engineer, but I work in an agency that has hundreds of them. I'll send this along to one of them and see if it's even remotely plausible.

You know the Discovery Channel had an abysmal show on "what if the Great Red Spot was on Earth...flattening Miami just like that." This sounds strangely like that.

during Katrina they said that if it would have made landfall at 175mph, that a few skyscrapers in New Orleans may have toppled. Lots of those buildings can only take 150-250mph wind gusts. Also, some of the older buildings are even weaker. It would take a monster hurricane to actually acomplish this though. We have yet to see a cat. 5 wind speed in a major U.S. city (the closest was Miami with Andrew...but even then, downtown Miami only saw about Cat. 2 force winds). I think that most would probably NOT collapse...but I could see 1 or 2 collapsing if a STRONG Cat. 5 hit a major city dead on.

It depends on where they're rooted...In NYC, they're rooted in bedrock...down south in sedimentary rock/limestone.

Engineer I have coffee with said it'd be possible for prolonged 180+ winds, more than 6 hours of Cat 5 winds (which isn't likely), but not likely. Gutted yes, fall over, probably not.

[ROCK]

the scenario is pure science fiction. The NHC would NEVER not issue advisories while a system is impacting land, when there is a well-defined eye, like there would be in a category 3 hurricane. Advisories would begin, even if they were waiting, when a consensus Dvorak reached 2.0 or 2.5

there would be 3 hourly recon scheduled well before as well

Houston will never fare worse than Lauderdale did in Wilma. IT'S 50 MILES INLAND.

The death toll is also extremely unrealistic. There is no way a hurricane in a non storm surge prone region is going to cause as many deaths as did Treblinka

Actually, as a crow flys downtown Houston is only about 40 miles inland...but you also need to consider Galveston bay which runs about 30-40 miles inland. If a hurricane were to go right up Galveston bay (which can be over 90F in the summer), then it may be able to maintain intensity or intensify. Because of Galveston Bay, some places in south Houston would actually see major storm surges during a cat. 5 hurricane as well as Galveston and all other areas of the coast. In 1983 with Hurricane Alicia, which was only a weak Cat. 3 at landfall, downtown Houston saw gusts over 100mph...enough to blow out thousands of windowns in downtown skyscrapers. IF a CAT. 5 were to come right up Galveston bay, then downtown Houston could still see Cat. 5 conditions...THAT would be the worst case scenario as many would not have left town and be surprised when 200mph gusts started ripping through thier neighborhood. I think if that kind of scenario were to play out...the death toll could certainly surpass 5-10K.

Just to clarify. Most of the windows DT were blown out from loose gravel on adjacent roofs. Back then, most roofs were the tar and gravel type.

The only gust I saw even close to (90mph)100mph (per the NHC) was at hobby Airport which is 10 or so miles away from DT. You might have had gust that high at higher elevations though.

Also Galveston Bay is extremely shallow (I know I have a beach house on the west end, stupid me). Not counting the channel, water is only about 7-10ft deep. Not sure even at 90F, that a TS could sustain its strength over these waters.

I would go high end cat 2 winds DT with gusts into 3 range if a 5 hit Freeport / Galveston.

I still have to diagree. Even if there was no bay...it all has to do with the speed of a storm. Hurricane charley struck Florida as a Cat.4, but 50 miles inland there was still cat. 3+ damage. Why? Well the storm was moving at 25mph, thus it was gaining more ground as it weakened. Were a Cat. 5 to hit the upper Texas coast moving at 25mph, it would probably still be a Cat. 4 downtown...may be a strong 3 if it had a weak eye structure. Also, storms have remained hurricanes for long distances inland. Charley, for example, crossed the state of Florida from Punta Gorda to Daytona Beach without losing hurricane strength. Also, Hurricane Hugo hit S.C. as a Cat. 4 and remained a hurricane all the way to past Charlotte, NC. Even with Katrina; hurricane force winds were recorded over 150 miles inland. Basically, the point I am trying to make is that the stronger the storm, and the faster the speed, the further inland the swath of strong winds will occur. Worst case scenario for Houston (in my mind) is a 165mph cat. 5 landfall on Galveston, it then moves up Galveston Bay and weakens to a Cat. 4; Downtown Houston then gets Strong Cat. 3/Weak Cat. 4 winds with gusts over 150mph. At IAH a gust hits 139mph before the wind gauge fails. Then, the eye turns towards the woodlands. In the woodlands they get 100mph sustained winds, but gusts still top 130mph. In Conroe they report gusts to 121mph. Then, EVENTUALLY the storm reaches Lufkin where a gust to 85mph is clocked. The storm eventually dies to a TS shortly after and finally becomes a TD once reaching Little Rock, AK (keep in mind that Katrina was still a weak TS in Tenessee...so a TS all the way to Arkansas is very possible). And that is MY version of Houston's worst case scenario...but with nature you never know...she has her own plans...anything is possible...but I think a storm stronger than a Cat. 2 is very possible in downtown Houston.

Worst case scenario for sure. I have to do some research but I do not recall a TS ever slamming into any part of the Texas coast at 25mph. Not saying it cant happen. Hell ,after 05 anything can happen.

[Scorpion]

A large Cat 5 approaching the Texas coast will likely draw in tons of dry air, and the fact that alot of the CDO will be over land doesn't help either.

[MiamiensisWx]

A large Cat 5 approaching the Texas coast will likely draw in tons of dry air, and the fact that alot of the CDO will be over land doesn't help either.

Actually, the cause of weakening of several Category Four or Category Five hurricanes (e.g., Allen from 1980) was not entirely from dry air intrusion, but from shear. The same thing happened to Katrina before landfall.

Also, you are saying that Texas cannot get a Category Five landfall. What about extreme southern Texas and Mexico, however?

[Normandy]

A large Cat 5 approaching the Texas coast will likely draw in tons of dry air, and the fact that alot of the CDO will be over land doesn't help either.

]

Im sorry but I dont understand how just because it hits Texas for some miraculous reason the CDO would be over land. A hurricane's cdo would be half over water, half over land no matter where it hits along the nortnern and western gulf coast.

[Scorpion]

A large Cat 5 approaching the Texas coast will likely draw in tons of dry air, and the fact that alot of the CDO will be over land doesn't help either.

]

Im sorry but I dont understand how just because it hits Texas for some miraculous reason the CDO would be over land. A hurricane's cdo would be half over water, half over land no matter where it hits along the nortnern and western gulf coast.

Yes and the fact that half the CDO is over land means thats 50% of the storm not getting in moisture.

[Extremeweatherguy]

A large Cat 5 approaching the Texas coast will likely draw in tons of dry air, and the fact that alot of the CDO will be over land doesn't help either.

]

Im sorry but I dont understand how just because it hits Texas for some miraculous reason the CDO would be over land. A hurricane's cdo would be half over water, half over land no matter where it hits along the nortnern and western gulf coast.

Yes and the fact that half the CDO is over land means thats 50% of the storm not getting in moisture.

well then the same thing should happen when a storm is hitting Florida too right...most of the outer bands are over the peninsula before landfall, yet many storms tend to strengthen before hitting.

[Scorpion]

A large Cat 5 approaching the Texas coast will likely draw in tons of dry air, and the fact that alot of the CDO will be over land doesn't help either.

]

Im sorry but I dont understand how just because it hits Texas for some miraculous reason the CDO would be over land. A hurricane's cdo would be half over water, half over land no matter where it hits along the nortnern and western gulf coast.

Yes and the fact that half the CDO is over land means thats 50% of the storm not getting in moisture.

well then the same thing should happen when a storm is hitting Florida too right...most of the outer bands are over the peninsula before landfall, yet many storms tend to strengthen before hitting.

Florida is a peninsula so there is water on the other side. Also its not directly a part of the continental landmass, only the panhandle is.

[Extremeweatherguy]

A large Cat 5 approaching the Texas coast will likely draw in tons of dry air, and the fact that alot of the CDO will be over land doesn't help either.

]

Im sorry but I dont understand how just because it hits Texas for some miraculous reason the CDO would be over land. A hurricane's cdo would be half over water, half over land no matter where it hits along the nortnern and western gulf coast.

Yes and the fact that half the CDO is over land means thats 50% of the storm not getting in moisture.

well then the same thing should happen when a storm is hitting Florida too right...most of the outer bands are over the peninsula before landfall, yet many storms tend to strengthen before hitting.

Florida is a peninsula so there is water on the other side. Also its not directly a part of the continental landmass, only the panhandle is.

yeah, but think of it this way. The mid part of Florida is about 100 miles across (more at some parts)...so why would it be any different if the eye was just off shore of the east coast of Florida with bands over the state and a storm with an eye right off of the coast of Texas with the outer bands to the west. Also, what about small storms..they are relatively compact. Also..Category 4 storms HAVE hit the upper Texas coast many times in the past..so we certaintly know that a storm over a cat. 3 is quite possible along the upper Texas coast. Also, as for some of the other things I have heard that would prohibit storm strengthening...the water off the coast of Texas is no colder than the water on the west coast of Florida (Usually that is. Now I know one of you will go out of your way to find that one example of when this was not true..but for the most time it is). Also, the air over Texas is not always drier than the air over Florida. You need to think of all the scenarios, not just one....and the same goes with shear...it is not ALWAYS stronger over the western Gulf. Many people are saying that it is impossible for a Cat. 5 to hit the upper Texas coast..but really it is not. After this last season, I am surprised to see that many don't think anything is possible. If I would have asked you last year if three Cat. 5 storms would develop in 2005, 99% of you would have said that it was impossible...but I guess it was not. Just because it has not happened in the last 150 years, does not mean that it never will. Plus if the global warming theory is correct, then we are going to see things we have never seen before. As for now, my worst case for Houston is still a Cat. 5 landfall and Cat. 4 winds downtown.

[Derek Ortt]

Charley and Wilma intensified due to QG factors. You're not going to see that if a system is moving NW.

I have serious doubts regarding some of the past cat 4's, based upon the devastation of Rita. Likely, they were cat 3's that weakened from 4's and 5's just before landfall. Remember, Rita had winds close to 100KT, yet it had a pressure of about 935mb. Rita eliminated all traces of towns like Holly Beach; thus, hurricanes like the 1900 Galveston may very well have been cat 3's since the surge from a large 3 would be equal to that caused by the Galveston storm

[milankovitch]

I'm going to agree with Extremeweatherguy if you can have a Camille why can't a cat 5 make landfall at Galveston. The water's aren't warm as far down but if the system is moving at a decent clip that shouldn't be a problem. A cat 5 at landfall would be made more probable if the system was strengthening up until landfall reaching peak intensity right before landfall. I also agree that a smaller storm could be mostly over water right up until landfall and would more easily make landfall as a cat 5.

As far Rita, just because that storm weakened before landfall shouldn't mean all storms weaken before landfall. Even though I myself believe that many past storms winds were over estimated based on 2005. I wish observations of today's quality went back 200 years. If they did we would be able to answer this question more definitivly. In the end though I think if you accept that Camille was a cat 5 then Galveston should be able to get a cat 5. It surely isn't common but it seems possible.

[Normandy]

Carla and the Indianola hurricane both hit the texas coast as near cat 5's, and Scorpion I wasnt refering to Florida when I was arguing how your theory about half the circulation being over land prohibiting a cat5....i was bascially arguing Camille and how it is proclaimed to be a 5 (when it hit the MS coast).

[wxmann_91]

Nothing is impossible, but a Cat 5 making landfall in any portion of the Gulf Coast (aside from the west coast of Florida and Mexico) is pretty hard to achieve. Reason, a cane traveling north or northwest is unfavorable for hurricanes to maintain their intensity, since most shear is from a westerly or southwesterly direction, meaning that the shear vector is perpedicular to the storm motion vector, enhancing its negative effects. Add in low Heat Content and dry continental air being entrained into a hurricane's circulation and it's no wonder why hurricanes struggle in the north and northwest GOM so much.

Normandy, Carla peaked at Cat 5 right before making landfall, so it was weakening as it was making landfall.

[MGC]

Opal was moving with the shear and still weakened. Big factor in the GOM is the loop current. Once a major hurricane move off the loop current most all have weakened. The exceptions I know of are Fredrick and Betsy. Fredrick never did ride the loop current and Betsy CP, as reported by recon was dropping as she approached Grand Isle. Really, I just think we have been very lucky that many major hurricanes have weakened due to external or internal factors. Personally, I think it is naive to dismiss the possibility of a Cat-4 or 5 landfall along the N GOM based on the past several major hurricanes that stumble near the coast......MGC

[Normandy]

I know, I said it was a near Cat5.

[AussieMark]

A Category Five may be able to make landfall in coastal extreme southern Texas or Mexico, however.

Didn't Beulah and Allen weak from 5's to a 3 in hrs prior to landfall on Southern Texas coast

[WaitingForSiren]

I think the most important problem with GOM hurricanes is eye wall replacement cycles. I think that is more important than shear (minimal shear i mean). Think about it, once the hurricanes are sitting in the loop current with 85-90 degree water and minimal shear they are likely to blow up into monsters. So since they have such a long distance to travel to the coast from when they reach their peak intesity, the eyewall replacement cycles occur prior to landfall. I think that is why Camille was so strong, it went through a cycle early then recovered in time to have a tight eye.

[wxmann_91]

I think the most important problem with GOM hurricanes is eye wall replacement cycles. I think that is more important than shear (minimal shear i mean). Think about it, once the hurricanes are sitting in the loop current with 85-90 degree water and minimal shear they are likely to blow up into monsters. So since they have such a long distance to travel to the coast from when they reach their peak intesity, the eyewall replacement cycles occur prior to landfall. I think that is why Camille was so strong, it went through a cycle early then recovered in time to have a tight eye.

The satellite presentation of Katrina as she was making landfall did not indicate any signs of ERC. Another thing is that ERC's tend to not occur in waters that are not extremely high in SST and/or Heat Content/water depth. (In other words, Cat 5's in the Caribbean go through numerous ERC's yet other canes in the tropical Atlantic/GOM tend to be more annular/undergo fewer ERC's.)

[ROCK]

Nothing is impossible, but a Cat 5 making landfall in any portion of the Gulf Coast (aside from the west coast of Florida and Mexico) is pretty hard to achieve. Reason, a cane traveling north or northwest is unfavorable for hurricanes to maintain their intensity, since most shear is from a westerly or southwesterly direction, meaning that the shear vector is perpedicular to the storm motion vector, enhancing its negative effects. Add in low Heat Content and dry continental air being entrained into a hurricane's circulation and it's no wonder why hurricanes struggle in the north and northwest GOM so much.

Normandy, Carla peaked at Cat 5 right before making landfall, so it was weakening as it was making landfall.

I agree. Even if you have a perfect shear environment the low heat content and dry air entrainment is enough to knock them down a notch. We saw this with Katrina (per the NHC) when her north western side started to take on some dry air prior to landfall. Not saying it can't happen but there is a reason why only 4 cat5's have made landfall in the US. Even that could be argued.