EPAC: JOHN - Remnants - Discussion

[SconnieCane]

Did John originate from the same CAG that is giving us PTC 9/soon-to-be Helene? I recall some model runs of the CAG were depicting a bundle of low-level vorticity on the EPAC side, but stopped paying attention when the runs began to come in stronger for the Atlantic system because it's usually an either/or situation. This is the first instance in my memory where a CAG has been modeled to induce tropical cyclogenesis on both sides of Central America, and it's actually come to fruition.

[mpic]

Seeing scenarios from a Cat 4 at landfall and total dissipation before it hits the Gulf? Is this go8ng to be simething to watch or not? Will the cooler temps coming in this week keep it from redeveloping in the Gulf if there's anything left over?

[al78]

Looks like a very compact system with TS winds extending only 40nm at most. I wonder if this counts as a midget tropical cyclone.

[SconnieCane]

Looks like a very compact system with TS winds extending only 40nm at most. I wonder if this counts as a midget tropical cyclone.

This small size is probably why it is expected to have minimal if any deleterious influence over soon-to-be Helene in the Atlantic.

[cycloneye]

 https://x.com/NHC_TAFB/status/1838309816516907447

[Pasmorade]

 https://x.com/NHC_TAFB/status/1838309816516907447

Yikes. Once John makes landfall, there'll be a massive storm surge...

[aspen]

Yikes, another Otis-like scenario playing out: small TC forming near the Mexico coast that unexpectedly bombs out into a major.

[Pasmorade]

000
WTPZ45 KNHC 232049
TCDEP5

Hurricane John Discussion Number 6
NWS National Hurricane Center Miami FL EP102024
300 PM CST Mon Sep 23 2024

John continues to rapidly strengthen. The latest subjective Dvorak
intensity estimates range from 65 to 77 kt, while the latest
objective intensity estimates are a little higher, in the 79 to 90
kt range. On infrared satellite imagery, the area of cold cloud
tops continues to grow, and the inner core is becoming more
symmetric. The latest visible images have shown hints of a small
eye, that has become a little more apparent in the last few hours.
Based on the above data and recent satellite trends, the initial
intensity is increased to 85 kt, making John a category 2 hurricane.

Environmental parameters continue to be ripe for additional rapid
intensification, with very warm ocean temperatures, weak vertical
wind shear and a moist atmosphere. The only potential limiting
factor could be how John might interact with the mountainous
topography of Mexico as the hurricane approaches the coastline. The
DSHIPS and LGEM statistical intensity models remain at the higher
end of the guidance envelope and show John becoming a major
hurricane as it approaches the coast. The EC SHIPS Rapid Intensity
Index is depicting a high likelihood of continued rapid
intensification over next 12 hours. The latest NHC forecast is near
the high end of the intensity guidance and continues to show John
strengthening to a 105-kt hurricane. It is possible that John could
peak even higher than shown below between the 12 h forecast point
and when it reaches the coast.

John continues to move due northward, now at 5 kt. The current
motion and the latest model guidance has again necessitated a
westward track shift to the NHC forecast. Given the updated track
forecast, the government of Mexico has extended the hurricane
warning westward.


KEY MESSAGES:

1. John is expected to continue rapidly intensifying, and is
forecast to become a major hurricane before the center reaches the
coast of southern Mexico within the Hurricane Warning area tonight
or early Tuesday. Damaging hurricane-force winds and a
life-threatening storm surge are expected within portions of the
hurricane warning area.

2. John will bring very heavy rainfall to coastal portions of
southern Mexico through this week. This heavy rainfall will likely
cause significant and possibly catastrophic, life-threatening flash
flooding and mudslides to the Mexican States of Chiapas, Oaxaca, and
southeast Guerrero, particularly in areas near the coast.


FORECAST POSITIONS AND MAX WINDS

INIT 23/2100Z 15.5N 98.5W 85 KT 100 MPH
12H 24/0600Z 16.0N 98.3W 105 KT 120 MPH
24H 24/1800Z 16.5N 98.3W 65 KT 75 MPH...INLAND
36H 25/0600Z 16.7N 98.4W 30 KT 35 MPH...POST-TROP/INLAND
48H 25/1800Z...DISSIPATED

$$

[tolakram]

saved loop

[al78]

 https://x.com/NHC_TAFB/status/1838309816516907447

Yikes. Once John makes landfall, there'll be a massive storm surge...

Surely the tiny breadth of TS and H winds will limit the peak surge height, rather like hurricane Charley in 2004. The maximum extent of hurricane force winds through to landfall is 10nm, this is like a very wide tornado.

[WaveBreaking]

Yikes, another Otis-like scenario playing out: small TC forming near the Mexico coast that unexpectedly bombs out into a major.

Yeah, this part of the EPAC honestly feels like its own basin with how little data is available there and the general odd behavior of TCs that form here. Something tells me that Otis and John were not the first hurricanes in this region to pull off sudden and dramatic RI episodes.

[WaveBreaking]

Latest Sandwich loop:

[Landy]

A bit upsetting to see that seemingly nothing has been learned since Otis. No idea why recon wasn't scheduled for until tomorrow afternoon, especially now that it's a coin flip's chance whether this is even still offshore by then.

[Landy]

Eye warming quickly

[REDHurricane]

A bit upsetting to see that seemingly nothing has been learned since Otis. No idea why recon wasn't scheduled for until tomorrow afternoon, especially now that it's a coin flip's chance whether this is even still offshore by then.

Makes me wonder if the NHC chooses to de-prioritize EPac storms that are only going to impact Mexico and not the U.S. -- because I can almost guarantee you that this storm would have been named/advisories updated quickly enough to reflect this system's unexpected rapid intensification if it was about to hit Texas or Florida instead of southern Mexico...

[Category5Kaiju]

Yikes, another Otis-like scenario playing out: small TC forming near the Mexico coast that unexpectedly bombs out into a major.

Yeah, this part of the EPAC honestly feels like its own basin with how little data is available there and the general odd behavior of TCs that form here. Something tells me that Otis and John were not the first hurricanes in this region to pull off sudden and dramatic RI episodes.

Nope, Otis and John aren’t alone indeed. Pauline in 1997 behaved similarly too. Ended up being a very deadly hurricane. Slow-moving, rapidly intensifying systems in this specific region of the Pacific, especially during the fall, are not exactly uncommon. But I will admit that Otis was quite shocking in its own way given how absurdly fast and suddenly it intensified.

[aspen]

Yikes, another Otis-like scenario playing out: small TC forming near the Mexico coast that unexpectedly bombs out into a major.

Yeah, this part of the EPAC honestly feels like its own basin with how little data is available there and the general odd behavior of TCs that form here. Something tells me that Otis and John were not the first hurricanes in this region to pull off sudden and dramatic RI episodes.

Nope, Otis and John aren’t alone indeed. Pauline in 1997 behaved similarly too. Ended up being a very deadly hurricane. Slow-moving, rapidly intensifying systems in this specific region of the Pacific, especially during the fall, are not exactly uncommon. But I will admit that Otis was quite shocking in its own way given how absurdly fast and suddenly it intensified.

Otis is in a league of its own. The fact that we had a storm all the forecasters and models thought would peak as a TS blow up into a Cat 5 landfall in a densely populated area was an unprecedented worst-case scenario. This part of the EPac definitely needs to be monitored more, as it’s prone to this unexpected major landfalls.

[Landy]

Last 24 hours

[Kingarabian]

Looks like it's bordering on major hurricane status.
Depending on the frame, anywhere from a T5.5 to T6.0.

[CrazyC83]

If only we had Recon - for all we know, this could be a solid major hurricane right now.