EPAC: OTIS - Aftermath - Discussion

[Cyclenall]

It's strange to see this thread with only 12 pages for such a historic storm
We're all caught off guard.

I almost missed it altogether if it weren't for a quick look at TWN (my weather network here in Canada) that had a news panel of Otis potentially coming in as a 5 - which obv got my attention since I thought it was just a TS.

[Xyls]

Holy moly. Had a long day at work yesterday and came home and went immediately to bed so hadn't heard that Otis had blown up like this.

This is probably this biggest hurricane forecasting failure of the 21st century.

[cycloneye]

Hurricane Otis Discussion Number 14
NWS National Hurricane Center Miami FL EP182023
1000 AM CDT Wed Oct 25 2023

The center of Otis continues to move farther inland, and assuming a
typical overland decay rate, the current intensity estimate is
reduced to 70 kt. These hurricane-force winds are likely occurring
over a small area near the center of the circulation. Otis should
continue to weaken rapidly over the rugged terrain of southern
Mexico today, and the system is expected to dissipate by late
tonight.

Otis is moving north-northwestward at about 345/9 kt. A ridge to
the northeast of Otis and a trough to its northwest should
continue to steer the cyclone north-northwestward until dissipation
in 24 hours. The official track forecast is very similar to the
previous advisory.


Key Messages:

1. Hurricane-force winds are still occuring inland over the
mountainous terrain of southern Mexico near the center of Otis.

3. Heavy rains from Otis will continue to impact areas of southwest
Mexico through Thursday. This rainfall will produce flash and
urban flooding, along with mudslides in areas of higher terrain.


FORECAST POSITIONS AND MAX WINDS

INIT 25/1500Z 18.2N 100.6W 70 KT 80 MPH...INLAND
12H 26/0000Z 19.4N 101.1W 35 KT 40 MPH...INLAND
24H 26/1200Z...DISSIPATED

$$
Forecaster Pasch

[Xyls]

Both internet and other communication services are almost completely lost after Otis. But slowly some videos and images are coming through and the damage looks total. I hope the damage somehow turns out to be 'less than expected' as we get more images now that the sun rises, but I'm afraid this is like Mexico's equivalent of Katrina.

I think this storm is probably too small to be a Katrina type storm surge event, but it could very well be an Andrew/Charley equivalent with wind.

[ScottNAtlanta]

Two days ago anyone that stated this could be a Cat 5 would have been ridiculed (with good reason most times since it borders on trolling and wishcasting). This just goes to show that we sometimes don't know things as well as we think.

[Sciencerocks]

[Astromanía]

This storm did what he wanted, wasn't forecast to be a hurricane let alone a cat 5, wasn't forecast to make landfall directly on Acapulco, it's like he did all on purpose

[wxman57]

I have an issue with this statement in the NHC discussion:

"assuming a typical overland decay rate, the current intensity estimate is reduced to 70 kt."

Bad assumption. You cannot assume a typical decay rate for a storm moving across tall mountains. Mountains can kill even a strong hurricane in 3-6 hours. I was debating whether Otis still had any TS winds.

[cycloneye]

There is not a lot of information from Acaplulco of the aftermath. Hopefully we will know very soon and is not the bad news.

 https://twitter.com/ClintonHaVi/status/1717062382290186357

[Ubuntwo]

Obs from an AWS in Roqueta Island (107m elevation). At 06:45Z, the station recorded an MSLP of 957.4 mb in the eyewall with sustained winds of 70.6 kt, gusting to 116 kt. The station continuously reported gusts above 100kt from 06:30Z to 07:30Z, with a maximum of 117.2 kt!

https://i.imgur.com/MgFrQD3.png
https://i.imgur.com/f7Vj951.png

Wind direction obs from this station suggest Otis passed just to the east, implying the storm tracked directly into Acapulco bay.

[Iceresistance]

Just found this image, with a separate comparison image...


https://s6.gifyu.com/images/S8bGz.jpg

It was this

https://s6.gifyu.com/images/S8bGq.jpg

[Iceresistance]

This was from the Hospital last night...

 https://twitter.com/RandomHeroWX/status/1717197672640024611




And the Princess Hotel

 https://twitter.com/volcaholic1/status/1717145326295908396

[AlabamaDave]

Is it just my imagination, or did it look like the eye was "falling apart" a little before Otis crossed the coastline. Any chance he weakened below catastrophic levels before the worst reached Acapulco? I know there has been widespread damage, but the devastation from a weakening storm would be "better."

[Zonacane]

Is it just my imagination, or did it look like the eye was "falling apart" a little before Otis crossed the coastline. Any chance he weakened below catastrophic levels before the worst reached Acapulco? I know there has been widespread damage, but the devastation from a weakening storm would be "better."

No, satellite does not accurately reflect the position of the storm

[wxman57]

Is it just my imagination, or did it look like the eye was "falling apart" a little before Otis crossed the coastline. Any chance he weakened below catastrophic levels before the worst reached Acapulco? I know there has been widespread damage, but the devastation from a weakening storm would be "better."

Yes, it appears that Otis was weakening at landfall. The eye was nearly filled as it crossed the coast. Dry air entrainment from inland may have led to some weakening.

[Fancy1002]

Is it just my imagination, or did it look like the eye was "falling apart" a little before Otis crossed the coastline. Any chance he weakened below catastrophic levels before the worst reached Acapulco? I know there has been widespread damage, but the devastation from a weakening storm would be "better."

Yes, it appears that Otis was weakening at landfall. The eye was nearly filled as it crossed the coast. Dry air entrainment from inland may have led to some weakening.

So the question is, did it make landfall at 160 or 155?

[wxman57]

Is it just my imagination, or did it look like the eye was "falling apart" a little before Otis crossed the coastline. Any chance he weakened below catastrophic levels before the worst reached Acapulco? I know there has been widespread damage, but the devastation from a weakening storm would be "better."

Yes, it appears that Otis was weakening at landfall. The eye was nearly filled as it crossed the coast. Dry air entrainment from inland may have led to some weakening.

So the question is, did it make landfall at 160 or 155?

With no recon or observations, we'll never know if it was 160, 155, or less. Damage assessment crew may provide some insight.

[CrazyC83]

Obs from an AWS in Roqueta Island (107m elevation). At 06:45Z, the station recorded an MSLP of 957.4 mb in the eyewall with sustained winds of 70.6 kt, gusting to 116 kt. The station continuously reported gusts above 100kt from 06:30Z to 07:30Z, with a maximum of 117.2 kt!

https://i.imgur.com/MgFrQD3.png
https://i.imgur.com/f7Vj951.png

That supports the thought the eye went a bit farther east than the satellite angle suggests. The eye probably went right over the city looking at the limited reports I have found, and the pressure gradient was likely razor-sharp.

[CrazyC83]

I have an issue with this statement in the NHC discussion:

"assuming a typical overland decay rate, the current intensity estimate is reduced to 70 kt."

Bad assumption. You cannot assume a typical decay rate for a storm moving across tall mountains. Mountains can kill even a strong hurricane in 3-6 hours. I was debating whether Otis still had any TS winds.

Agreed. There's no way it is a hurricane now. I'd probably have something like 55-60 kt at the 12Z best track position and right now I'd put it at 30 kt.

[cycloneye]

BULLETIN
Tropical Storm Otis Intermediate Advisory Number 14A
NWS National Hurricane Center Miami FL EP182023
100 PM CDT Wed Oct 25 2023

...OTIS NOW A TROPICAL STORM INLAND...
...HEAVY RAINFALL AND FLASH FLOODING CONTINUES OVER PORTIONS OF
SOUTHERN MEXICO...


SUMMARY OF 100 PM CDT...1800 UTC...INFORMATION
----------------------------------------------
LOCATION...18.6N 100.7W
ABOUT 130 MI...205 KM NNW OF ACAPULCO MEXICO
MAXIMUM SUSTAINED WINDS...60 MPH...95 KM/H
PRESENT MOVEMENT...NNW OR 335 DEGREES AT 10 MPH...17 KM/H
MINIMUM CENTRAL PRESSURE...995 MB...28.38 INCHES