EPAC: JOHN - Remnants - Discussion

[CrazyC83]

I'd put out a Special Advisory with a 50 kt intensity and a hurricane forecast...

[Kingarabian]

Steering is not gonna give it much time over water. Basically needs to form within the next 12 hrs.

Don't really see that. The 00z EPS doesn't have it approach the shore for quite a while, and we saw this occur with Max last year. This may linger around for 3 days before landfall. Some members even make it a hurricane, and if current organization is anything to go by, I would agree.

Looks like it'll meander just off the coast for at least a few cycles. Model runs from 24 ago hours had this interacting with the coast much sooner. Unfortunately looks like a much serious threat than modeled.

[Hurricane2022]

I'm just hoping this don't becomes a Hurricane Otis II...

[Teban54]

IMO, this only adds more to the puzzle of why NHC has been so conservative this year.

Not designating Atlantic systems that look like TDs (occasionally even with TS winds) if they're expected to be short-lived? That's meteorologically inaccurate, but at least still justifiable from an impact perspective.

Not declaring 97L as an invest when landfall was within 5 days and hurricane impacts appeared increasingly likely? Concerns about human impacts would have argued otherwise, but at least you can still say that there wasn't an apparent center in the CAG until just before the invest was actually declared.

Not naming 10E when it's probably well on its way to becoming a hurricane? I don't even know where to begin.

No disrespect for the folks at NHC... But this is really head-scratching.

[Hurricane2022]

The NHC needs to wake up quickly. They should upgrade it to atleast 40 kt in the next intermediate advisory, and the Mexican Gov needs to start issuing Hurricane Watches now.

[ElectricStorm]

Tropical Storm John Intermediate Advisory Number 2A
NWS National Hurricane Center Miami FL EP102024
1200 AM CST Mon Sep 23 2024

...DEPRESSION BECOMES TROPICAL STORM JOHN...
...LIKELY TO BRING LIFE-THREATENING FLOODING TO PORTIONS OF
SOUTHERN MEXICO EARLY THIS WEEK...


SUMMARY OF 1200 AM CST...0600 UTC...INFORMATION
-----------------------------------------------
LOCATION...14.1N 98.5W
ABOUT 150 MI...240 KM S OF PUNTA MALDONADO MEXICO
MAXIMUM SUSTAINED WINDS...40 MPH...65 KM/H
PRESENT MOVEMENT...STATIONARY
MINIMUM CENTRAL PRESSURE...1002 MB...29.59 INCHES

[lilbump3000]

https://www.youtube.com/@w.o.f.weathero ... irmation=1

[xtyphooncyclonex]

Hoping the agencies take this seriously. Not saying it will happen, but they better avoid an Otis-like forecast error early ob by at least considering microwave imagery and other sources besides Dvorak. Eyewall looks to be solid even for a TS. May be around 50-55 kts already, and could overperform the forecasts dramatically

[cycloneye]

Tropical Storm John Discussion Number 3
NWS National Hurricane Center Miami FL EP102024
300 AM CST Mon Sep 23 2024

Satellite images indicate that John continues to become better
organized, with very deep convection near the center and some tight
curved band features. Earlier microwave imagery also showed some
inner core development, with perhaps a partial eyewall trying to
form. Subjective Dvorak estimates at 06z were 35 kt from both
TAFB/SAB, though the objective values were between 40-50 kt. The
intensity is set to 40 kt as a blend of these data.

The storm is moving slowly to the north-northeast, caught in the
large-scale southwesterly flow associated with the monsoon trough
near Central America. There has been a big change in most of the
track guidance since yesterday, with a fair number of the models
now showing a steadier northeastward motion with less eastward
steering from the incipient tropical cyclone in the northwestern
Caribbean Sea. Consequently, the models have shifted leftward and
faster. The official forecast is also trended in that direction,
but could still be too far to the east.

John is forecast to be over very warm waters with light shear while
it approaches the coast of Mexico over the next day or so. While
none of the regional hurricane models make John a hurricane before
landfall, the rapid intensification indices are indicating at least
a 50 percent chance that this system strengthens 30 kt in the next
24 hours, which would indicate hurricane-strength. Given the
uncertainties involved, a Hurricane Watch and a Tropical Storm
Warning have been issued by the government of Mexico for portions of
the coast of southern Mexico on this advisory, and interests there
should closely monitor for future forecast updates.


KEY MESSAGES:

1. Slow-moving Tropical Storm John will bring very heavy
rainfall to coastal portions of southwest Mexico through the
upcoming 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.

2. John is forecast to strengthen before landfall, and a Hurricane
Watch and a Tropical Storm Warning have been issued for a portion
of the coastline of southern Mexico, where tropical storm
conditions could begin late today.

3. John could strengthen more than forecast depending on how
long it remains over water. Interests along the coast of southern
Mexico should monitor the latest forecast updates, as Hurricane
Warnings could be required for a portion of the coastline later
today.


FORECAST POSITIONS AND MAX WINDS

INIT 23/0900Z 14.4N 98.5W 40 KT 45 MPH
12H 23/1800Z 14.8N 98.2W 50 KT 60 MPH
24H 24/0600Z 15.4N 97.6W 60 KT 70 MPH
36H 24/1800Z 15.8N 97.2W 60 KT 70 MPH
48H 25/0600Z 16.0N 97.0W 45 KT 50 MPH...INLAND
60H 25/1800Z...DISSIPATED

$$

[Sciencerocks]

[doomhaMwx]

40 kts? NHC has a lot of catching up to do. This thing is building an eyewall and microwave-derived surface wind speed from this AMSR-2 pass is at/near 64 kts.

[Hurricane2022]

They did it.

...JOHN QUICKLY STRENGTHENING AS IT DRIFTS TOWARD THE COAST OF
MEXICO...
...HURRICANE WARNINGS ISSUED FOR PORTIONS OF SOUTHERN MEXICO...


SUMMARY OF 600 AM CST...1200 UTC...INFORMATION
----------------------------------------------
LOCATION...14.5N 98.5W
ABOUT 125 MI...200 KM S OF PUNTA MALDONADO MEXICO
ABOUT 155 MI...250 KM WSW OF PUERTO ANGEL MEXICO
MAXIMUM SUSTAINED WINDS...65 MPH...100 KM/H
PRESENT MOVEMENT...NNE OR 25 DEGREES AT 3 MPH...6 KM/H
MINIMUM CENTRAL PRESSURE...994 MB...29.35 INCHES

[StPeteMike]

Good thing they have hurricane warnings up for the coast.

[Kingarabian]

Dvorak supports a hurricane.

[Category5Kaiju]

Is this really happening?

John's attempting to pull an Otis-like trick? Dang, small storms + slow movement + headed toward Mexico isn't really a good combination....

[cycloneye]

EP, 10, 2024092312, , BEST, 0, 146N, 986W, 60, 992, TS

[kevin]

The only limitation with John is time, because other conditions are near-perfect. Current shear is only 2 kt, which almost sounds to good (or I guess bad) to be true. Looks to be around 60 - 65 kt right now. According to the NHC track the storm still has about 30 hours over water. Models are all over the place though. AI-RI has a 50% chance of 55kt/48 hr intensification, which would mean ~100 kt at landfall but none of the (hurricane) models are even close to that intensity. No clue what will happen, the John/97L combination is interesting for sure.

[kevin]

Most recent SHIPS (just released) has an 82% chance of RI . Also a 74% chance of 45kt/36hrs with a starting intensity of 60 kt. In other words a 74% chance of 105 kt at landfall.

[cycloneye]

Tropical Storm John Tropical Cyclone Update
NWS National Hurricane Center Miami FL EP102024
1000 AM CDT Mon Sep 23 2024

Recent satellite imagery indicates that John continues to become
better organized, and that it is likely to become a hurricane later
today. Continued strengthening appears likely while John approaches
the coast of southern Mexico within the Hurricane Warning area.
This will result in changes to the initial and forecast intensity
that will be reflected in the next forecast advisory issued by the
National Hurricane Center at 900 AM CST (1500 UTC).

$$
Forecaster Brown

[REDHurricane]

So did the NHC just fall asleep on this one because "it's just a small/weak-ish disturbance off the coast of Mexico that's going to make landfall soon so let's push this one aside to focus on other things" or what? This has nothing to do with the fact that they're the experts with PhDs and decades of experience in weather forecasting; when the same sloppy error is made multiple times in such a short time period it's becoming more and more clear to me that this is almost entirely an administrative/procedural issue. Not being able to predict an unexpected RI event 1-2 days in advance is okay; not paying close enough attention to it and/or not issuing warnings quickly enough while it's very obviously beginning to occur is not okay.