Central & Eastern Pacific Thread

[mob1]

10 minutes ago, olafminesaw said:

The first I've seen on the East side of the city. This would be where the surge would have occurred and appears to be significant standing water still.

 

 

 

Wow, that is some pretty impressive damage. Images coming out of rural areas aren't much better 

 

 

[LongBeachSurfFreak]

I’m actually shocked and appalled by the lack of coverage of this, soon to be, humanitarian crisis. This was the big one, for Mexico.

[Random Chaos]

11 minutes ago, LongBeachSurfFreak said:

I’m actually shocked and appalled by the lack of coverage of this, soon to be, humanitarian crisis. This was the big one, for Mexico.

I agree, but one of the coverage issues is the lack of information out of there. Even 1.5 days after the hurricane hit we are getting only a very few videos and pictures from the location. All the roads to there are inaccessible. And because of the short warning, media and storm chasers didn't have time to pre-stage near the landfall location. Until media is able to actually get access, I wouldn't judge too harshly the lack of coverage. If, once media can get access, lack of coverage continues, then I too will be appalled.

[Newman]

26 minutes ago, LongBeachSurfFreak said:

I’m actually shocked and appalled by the lack of coverage of this, soon to be, humanitarian crisis. This was the big one, for Mexico.

You hear nothing on the big news stations except the Maine and Israel situations. Mind you, those are big news stories in and of themselves. But this is a huge natural disaster just south of us and there's NO coverage at all. The images and videos coming out are just insane

[SchaumburgStormer]

Definitely need a mod to break this into its own thread. We will be talking about this hurricane for a long time 

[LongBeachSurfFreak]

1 hour ago, Random Chaos said:

I agree, but one of the coverage issues is the lack of information out of there. Even 1.5 days after the hurricane hit we are getting only a very few videos and pictures from the location. All the roads to there are inaccessible. And because of the short warning, media and storm chasers didn't have time to pre-stage near the landfall location. Until media is able to actually get access, I wouldn't judge too harshly the lack of coverage. If, once media can get access, lack of coverage continues, then I too will be appalled.

Based on our, immediate gratification news culture it will be too late. This is a once in a generation event. A major modern city basically set back to the Stone Age. This has major long term implications. 

[Bhs1975]

That’s what’s so impressive about this is the type of damage modern well built structures took. Not many examples come to mind especially with the high rise damage. There’s no question those taller structures took 200+ mph gusts to produce what we’re seeing. Think about Laura and lake Charles. That was a cat 4 with gusts to near cat 5 measured in the city and those high rises had mostly window damage. This completely gutted entire floors and any windward facades are just gone. It’s not just one building either, it’s all of them. I don’t even think there’s a remote comparison to this storm given the city it hit

I've always wondered what Cat 5+ winds would do to a high rise building. Looks like we'll be seeing a lot more of this.

[olafminesaw]

[Amped]

43 minutes ago, olafminesaw said:

Just imagining how much broken glass they'll have to avoid stepping on for the next 20 years.

I don't know building codes there.  If they didn't require storm windows that could help explain the near 100% failure rate of high rise windows across the city.

[Random Chaos]

With Otis in the news, I saw this paper on rapid intensification was published earlier this month, detailing both the typical rapid intensification plus a newly discovered mechanism of rapid intensification.

 

Article about the paper: https://phys.org/news/2023-10-scientists-ways-hurricanes-rapidly.html

The paper (paywall): https://journals.ametsoc.org/view/journals/mwre/151/10/MWR-D-23-0038.1.xml

[Normandy]

I thought this video is excellent and very instructive on the dangers of riding out a category five hurricane in a curtain wall system high rise building.  If you notice on this image the edges of the building are completely shredded of all interior walls.  The middle of the building is severely damage, but is only still in tact mostly because of the elevator and stair core (which is made of concrete and thus blocks the wind from completely shredding the middle).  If you are in a high rise structure with glass exterior walls, you will not survive a category five unless you shelter inside the interior stairwell.  Your bathroom or interior closet is not enough.  
 

[cptcatz]

Anyone know what kind of building codes they have there?  These high rises look modern with sleek glass but I wonder how well they are actually built...

[NorthHillsWx]

3 hours ago, SchaumburgStormer said:

Definitely need a mod to break this into its own thread. We will be talking about this hurricane for a long time 

Agree. This needs a post mortem thread so we can archive this on the forum. This was one of the top impacts we’ll ever see and its getting dissected on the general EPAC discussion 

[Windspeed]

Anyone know what kind of building codes they have there?  These high rises look modern with sleek glass but I wonder how well they are actually built...

The high-rise structures are built to withstand some pretty strong EQs. Acapulco exists on a subduction zone prone to violent quakes. Of course, that doesn't mean the guts of floors didn't have cheaper materials. But I'd imagine some of these more expensive high-rises that got gutted weren't cheap. The rich and famous like their Acapulco.

[Normandy]

High rise structures in general are governed by the IBC section 202, which is an international building code that is adopted by local enforcing agencies.  The california building code (CBC 403.1) is derived from this code, and one can most reasonably believe Acapulco and other modern cities in the western pacific coasts in North America adopt this code.  In other words….there is no high-rise in a modern city that is not well built.

Now you might ask: well why is it so easy for a cat five to shred these well built buildings?  High rise structures are comprised of the following things:

1) interior vertical core of stair and elevator systems, with walls of concrete construction and fire rated up to 3-hours.  This core of walls cannot be destroyed by the hurricane and effectively act as a safe room for the building at each level

2) exterior curtain wall skin (typically comprised of cladded portions with mostly glazed systems).  This can be rated for higher end hurricanes, but typically winds exceeding 115 mph can send airborne debris that can puncture these glazed panels.  This is why you often see high rise windows missing here and there when a major hurricane strikes a major city (ie New Orleans in Katrina, Wilma in Florida).  Outright failure of these systems require winds exceeding 145 mph.

3) interior demising unit walls (non structural connections to the deck and only rated for sound and impact).  These wall are food for winds greater than 115 mph as they offer no structural connections at the top and bottom to deal with wind pushing against them.  Once the wind rips the exterior skin off the high rise, the interior walls are just blown over and out where the wind is inside.  

The structure and core survive but the spaces around it around completely gutted and shredded.  Has nothing to do with being well built.  The structures still standing imply they are well built and code compliant.

[olafminesaw]

A survey of the city proper. Looks like overall the area around the bay fared better than the tourist strip

 

 

 

[Derecho!]

10 hours ago, Normandy said:

High rise structures in general are governed by the IBC section 202, which is an international building code that is adopted by local enforcing agencies.  The california building code (CBC 403.1) is derived from this code, and one can most reasonably believe Acapulco and other modern cities in the western pacific coasts in North America adopt this code.  In other words….there is no high-rise in a modern city that is not well built.

Now you might ask: well why is it so easy for a cat five to shred these well built buildings?  High rise structures are comprised of the following things:

1) interior vertical core of stair and elevator systems, with walls of concrete construction and fire rated up to 3-hours.  This core of walls cannot be destroyed by the hurricane and effectively act as a safe room for the building at each level

2) exterior curtain wall skin (typically comprised of cladded portions with mostly glazed systems).  This can be rated for higher end hurricanes, but typically winds exceeding 115 mph can send airborne debris that can puncture these glazed panels.  This is why you often see high rise windows missing here and there when a major hurricane strikes a major city (ie New Orleans in Katrina, Wilma in Florida).  Outright failure of these systems require winds exceeding 145 mph.

3) interior demising unit walls (non structural connections to the deck and only rated for sound and impact).  These wall are food for winds greater than 115 mph as they offer no structural connections at the top and bottom to deal with wind pushing against them.  Once the wind rips the exterior skin off the high rise, the interior walls are just blown over and out where the wind is inside.  

The structure and core survive but the spaces around it around completely gutted and shredded.  Has nothing to do with being well built.  The structures still standing imply they are well built and code compliant.

Takeway is that it is not feasible from a cost perspective to build high-rises in areas such as this that could survive a storm such as this  without massive damage, that people would actually want to live in (given the point of a high-rise on the beach is the view). 

[csnavywx]

Here's the EF-scale proposal for damage indicators:

https://www.depts.ttu.edu/nwi/Pubs/FScale/EFScale.pdf

Some pretty widespread Cat3+ damage (trees snapped including some palms, partially debarked). Curtain/interior walls suffering partial to complete failure in high rises. Some of them you can just see all the way through.

[Normandy]

@Derecho! hit the nail on the head with his astute observation.  To unpack the hood on this even further:  I’d like to explain in high rises what the interior spaces are actually designed to do in the event that a natural disaster like a fire or category five hurricane.  The building is suppose to ensure the safe egress of occupants out of said structure, and if that is not possible then occupants of the building need an area of refuge where they can shelter in place until they can be rescued.  this sentence means in laymen’s terms:  your condo is not designed to protect you in a category five hurricane.  However the high rise structure that your condo does sit in is designed to protect you if you go inside the stair well.  Developers and some architects won’t explicitly state this; the curtain wall systems of high rise buildings are designed to withstand 115 mph usually, but are assumed to fail in the event of winds greater than 155 mph.  This is why the code requires high rise structures to have interior fortress like stairwells and areas of refuge so people can hide.  
 

One thing I’d love to see incorporated into the building code for residential use in high-rise structures:  interior safe rooms (maybe 6’x6’) within each dwelling unit that are of forced to comply with the same code requirements as stairways.  Same concept as saferoom or basement in single family homes.  This could be a minimal cost approach that could help make these tall buildings a little safer than they already are.  All 700 tenants of a high rise structure shouldn’t have to hide in the stairwells during a cat 5

[DeltaPilot]

Did the Hurricane Hunters fly this storm? Seeing a lot of "debate" about what this storm actually was Strength wise when it made landfall. It was obviously undergoing degradation from terrain, but Im curious. Hard to believe the lack of coverage for this event. Damage looks to support at least a high end CAT 3 and easily a 4 from what I have seen so far.

[gymengineer]

From npr today- Conditions are grim in the city. https://www.npr.org/2023/10/27/1208982615/acapulco-mexico-hurricane-otis

[gymengineer]

The Lidia (10/10/23 landfall), Norma (10/21/23 landfall), Otis (10/25/23 landfall) sequence has got to be a record or tied a record for most hurricane landfalls in a single country in that short period of time, right?

Let alone the more astonishing fact of a Cat 4 and Cat 5 landfall separated by only 15 days in a single country- I can’t imagine that that’s ever happened in recorded history. 

[Ed, snow and hurricane fan]

Watching YouTube and discovered there is a Fox Weather Channel, and Bryan Norcross works there.  Besides the small nature of the storm and divergent pattern (in some ways a repeat of Ian, what was expected to weaken the system initially strengthened it) abnormally warm SST near-shore was explicitly mentioned as a factor in RI.

I do wonder if Florida high rise building codes are followed in Acapulco. 

[Random Chaos]

Those are some pricy boats totaled too…

 

[Floydbuster]

14 hours ago, DeltaPilot said:

Did the Hurricane Hunters fly this storm? Seeing a lot of "debate" about what this storm actually was Strength wise when it made landfall. It was obviously undergoing degradation from terrain, but Im curious. Hard to believe the lack of coverage for this event. Damage looks to support at least a high end CAT 3 and easily a 4 from what I have seen so far.

They didn't have a plane there at the time of landfall. The eye started to lose it's luster right at landfall, but based on the observed damage, my guess is that this came ashore as a Category 5. In fact, I'm guessing the peak intensity offshore was higher than the operational 165 mph. It probably was about 175 mph offshore, and came ashore in the 160-165 mph range.

A devastating Category 5 strike on Mexico. 

[Amped]

Not good, but not unexpected either.  Judging by the damage, the final death toll will probably be in the hundreds.

[Intensewind002]

3 hours ago, Amped said:

Not good, but not unexpected either.  Judging by the damage, the final death toll will probably be in the hundreds.

Reminds me of Dorian, Bahamian government reported there was only 86 fatalities yet people that were involved in helping with the aftermath said it was in the hundreds

[Amped]

I know I am inferring wind direction based on damage here.  But this is a video that shows lots of boats smashed into the shore. I geolocated the light house on google maps and it's RentaYateAcapulco. It is on a north facing beach on the hook of the western peninsula.  The damage would imply winds were out of the north there.   This could mean the storm tracked straight over the bay  which is a few miles east of the official track.

 

[Windspeed]

"Of the 6,870 hectares of buildings analyzed by emergency satellite products from
@CopernicusEMS
to estimate damage from #Otis to #Acapulco , 6,665 hectares (97 %) were affected, including 6,343 hectares ( 92 %) of damaged or destroyed buildings. Catastrophic."

[Windspeed]