2024 Atlantic Hurricane Season

[StantonParkHoya]

Will be interesting to follow the timing and the trough interaction. GFS does it again but the set up over the US MW is quite different each run.

[dbullsfan]

Now a lemon:

An area of low pressure could form this weekend over the western 
Caribbean Sea. Thereafter, some slow development of this system is 
possible through early next week while the system moves slowly to 
the north or northwest over the northwestern Caribbean Sea.
* Formation chance through 48 hours...low...near 0 percent. 
* Formation chance through 7 days...low...20 percent.

Seems like a lot of steam for only 20% or is that mostly because they think the development could be more than 7 days out?

Sorry for the weenie question but this one seems to have quite the buzz so the 20% kinda threw me off.


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[WxWatcher007]

3 minutes ago, dbullsfan said:

Seems like a lot of steam for only 20% or is that mostly because they think the development could be more than 7 days out?

Sorry for the weenie question but this one seems to have quite the buzz so the 20% kinda threw me off.


.

The TC genesis signal looks right on the edge of 7 days judging by the ensembles. While I think the CAG (Central American Gyre) signal is real and we have a good chance of something forming, I’d say we need more time to lock that signal. 

[Seminole]

If I am interpreting the 6Z GFS correctly. We have a high end tropical storm off the Panama City coast that somehow drifts south east and proceeds into the Apalachee Bay as a low end CAT 1. It then maintains high end tropical storm intensity to though the entire eastern seaboard and then regains hurricane intensity over Pennsylvania and New York (Subtropical?). 

[bdgwx]

Given that AI models generally tend to blur or smooth the forecasted fields [Bonavito 2024] the ECMW-AI looks really spicy.

[olafminesaw]

It seems to me the inhibiting factor for development could be the broad circulation may have trouble tightening. This seems to be why the GFS has a very large hurricane, while the Euro has shown on several runs a broad area of low pressure that never develops despite reasonably favorable conditions.

[Seminole]

55 minutes ago, bdgwx said:

Given that AI models generally tend to blur or smooth the forecasted fields [Bonavito 2024] the ECMW-AI looks really spicy.

 Massive! 

[jbenedet]

Having the repeat signals from the EPS and GEFS run after run is —as many have already stated—as strong an indication as any at this lead time that a strong tropical system is likely to develop. 
 

And then we have the MJO transition phase 6 to 7/8. The high amplitude troughiness seen across the central/Eastern CONUS on some of the op runs around the time of interest is much more likely than not…

[GaWx]

 The NHC lemon has just come into the 12Z UKMET’s 168 hour range and it has TCG at 162 in NW Caribbean 200 miles SSW of W top of Cuba moving NNE toward W Cuba on 9/25:

NEW TROPICAL CYCLONE FORECAST TO DEVELOP AFTER 162 HOURS
              FORECAST POSITION AT T+162 : 18.9N  86.2W

                        LEAD                 CENTRAL     MAXIMUM WIND
      VERIFYING TIME    TIME   POSITION   PRESSURE (MB)  SPEED (KNOTS)
      --------------    ----   --------   -------------  -------------
    1200UTC 25.09.2024  168  19.4N  86.0W     1004            27

[WxWatcher007]

1 hour ago, olafminesaw said:

It seems to me the inhibiting factor for development could be the broad circulation may have trouble tightening. This seems to be why the GFS has a very large hurricane, while the Euro has shown on several runs a broad area of low pressure that never develops despite reasonably favorable conditions.

This is a really good point, and is a good place for a reminder that usually CAG systems are slow to develop and are relatively lower ceiling at least initially because they can be so broad. Michael was an exception to the rule.

Turning to the GFS…it looks like the eastern trough is enough to take it north and then NE across FL, but then a ridge rolls over the northern U.S. and traps it from escaping OTS immediately in advance of another trough that could kick or draw north. 

Just one of many solutions but I think the Gulf and East Coast should be watching this one closely. This looks like a favorable intensification environment if a low can build a well-organized structure. 

[GaWx]

Other 12Z:

-GFS 988 into FL Big Bend early 9/27 and then ENE to N of Daytona

-CMC 974 Pensacola late afternoon 9/26

[yoda]

9 minutes ago, GaWx said:

Other 12Z:

-GFS 988 into FL Big Bend early 9/27 and then ENE to N of Daytona

-CMC 974 Pensacola late afternoon 9/26

Not sure I buy the 36 hour cutoff idea on the GFS as it sits off the GA/FL coast before finally deciding to skedaddle NE and out to sea

[WxWatcher007]

Just now, yoda said:

Not sure I buy the 36 hour cutoff idea on the GFS as it sits off the GA/FL coast 

I don’t either. These are vastly different run to run differences—to be expected as you know. 

[yoda]

Just now, WxWatcher007 said:

I don’t either. These are vastly different run to run differences—to be expected as you know. 

True, but I think this is the first time we have seen this type of solution.  I believe we are getting towards a "storm will be happening"... the question is strength and track.

[Kmlwx]

That first trough doesn't dig like earlier runs on that 12z GFS run - leaves it behind until another trough comes through. 

[GaWx]

12Z Euro: far NE TX 9/28 998 mb

12Z JMA: middle of Gulf 9/26 moving N 1004 mb 

12Z Euro ens: quite active with main US threat E LA to Tampa

[StantonParkHoya]

Seems like the model average is around Mobile

[CurlyHeadBarrett]

 

[StantonParkHoya]

1 minute ago, CurlyHeadBarrett said:

 

Less dust when the area is flooding

[StantonParkHoya]

18z GFS with some big changes. Less trough dig, more ridging into gulf, takes Cat 4/5 into Louisiana coast

[purduewx80]

The pattern that produced Wilma in ‘05 just moved to the top analog in the 6-10 day. 

[BRSno]

9 minutes ago, purduewx80 said:

The pattern that produced Wilma in ‘05 just moved to the top analog in the 6-10 day. 

18z GFS sure trended to something more like this

[Scott747]

Definite filth on the 18z GFS. TS winds from Galveston to New Orleans. Hurricane gusts from the Golden Triangle to Houma.

Still grain of salt type of run that far out.

 

[purduewx80]

10 minutes ago, BRSno said:

18z GFS sure trended to something more like this

Eh, Wilma intensified to an historic Cat 5 in the Caribbean. Current ensemble suite doesn’t suggest anything like a repeat, but in general the analogs are showing how we get a potential major hurricane to come north out of the Caribbean. Somewhere in the eastern half of the Gulf is most likely at this point, but there’s a huge amount of spread in timing and location, such that anywhere in the Gulf is probably fair game.  This one will have off-the-charts OHC to work with and will probably be able to take advantage of the loop current farther north, too. 

[Seminole]

35 minutes ago, StantonParkHoya said:

18z GFS with some big changes. Less trough dig, more ridging into gulf, takes Cat 4/5 into Louisiana coast

The Euro has stayed steady with the trough not influencing the potential TC. 

[NorthHillsWx]

Something about this gives me the vibe this is “the storm” of the year for the US. Lots of potential next week lots of model watching coming up. 

[TPAwx]

Probably an H storm so for sure a miss in TB.  We only take I storms seriously.

[GaWx]

21 minutes ago, TPAwx said:

Probably an H storm so for sure a miss in TB.  We only take I storms seriously.

 I storms have been extra damaging and/or deadly on the CONUS since Irene of 1999 and Isabel of 2003. Afterward, there was Ivan of 2004, Ike of 2008, Irene of 2011, Isaac of 2012, Irma of 2017, Isaias of 2020, Ida of 2021, Ian of 2022, and Idalia of 2023.

 Very damaging or deadly H storms for CONUS: Hazel of 1954, Hilda of 1964, Hugo of 1989, and Harvey of 2017.

 I storms overall have been the worst by a good margin of any letter for the CONUS the last 25 years.

[TPAwx]

Ok now GFS

[TPAwx]

What a beast of an op run