Major Hurricane Helene

[TPAwx]

Can’t get tweets to embed properly, but Andy Hazelton saying the 12z hurricane models will have TDR/Tail Doppler Radar ingested and should be more realistic with outputs.

[GaWx]

4 minutes ago, jbenedet said:

Significant -NAO patterns are good for displacing climatological patterns. This syntopic interaction and extra tropical transition is common to what is experienced in the northeast; unusual in the southeast…

And currently the -NAO is by far the strongest on record for September at below -2.7! The -NAO peak is today and tomorrow.

[GaWx]

12Z UKMET: E shift and a bit stronger vs 0Z bringing it into Apalachee Bay (instead of near Apalachicola) Thu night; goes to a little E of ATL vs near ATL on 0Z

TROPICAL STORM 09L        ANALYSED POSITION : 19.5N  83.5W

     ATCF IDENTIFIER : AL092024

                        LEAD                 CENTRAL     MAXIMUM WIND
      VERIFYING TIME    TIME   POSITION   PRESSURE (MB)  SPEED (KNOTS)
      --------------    ----   --------   -------------  -------------
    1200UTC 24.09.2024    0  19.5N  83.5W     1003            37
    0000UTC 25.09.2024   12  20.0N  85.3W      998            37
    1200UTC 25.09.2024   24  21.1N  86.0W      993            40
    0000UTC 26.09.2024   36  22.5N  86.3W      989            40
    1200UTC 26.09.2024   48  24.7N  85.5W      987            48
    0000UTC 27.09.2024   60  28.4N  84.4W      983            51
    1200UTC 27.09.2024   72  33.3N  83.3W      986            41
    0000UTC 28.09.2024   84  38.1N  84.1W      995            31
    1200UTC 28.09.2024   96  37.5N  90.7W     1000            17
    0000UTC 29.09.2024  108  36.4N  91.4W     1003            13
    1200UTC 29.09.2024  120  35.3N  92.4W     1007            12
    0000UTC 30.09.2024  132              CEASED TRACKING

 

[SnowGoose69]

6 minutes ago, StantonParkHoya said:

Yeah, call me skeptical. Never seen a TC that didn’t begin weakening rapidly upon LF.

Even Hugo moving at 25 was a 75-80 mph storm when it got to Charlotte so yeah, likely just a strong TS by the time it got to like ATL or near there but thats still bad with saturated ground.

[NorthHillsWx]

I am confused with the systems organization today. That naked swirl is definitely the COC recon found but there is no reason why is should be going south. It doesn’t appear to be part of a larger cyclonic gyre but I guess that is the only explanation 

[Normandy]

2 minutes ago, NorthHillsWx said:

I am confused with the systems organization today. That naked swirl is definitely the COC recon found but there is no reason why is should be going south. It doesn’t appear to be part of a larger cyclonic gyre but I guess that is the only explanation 

Both things can be true:  that is the COC and it’s still embedded within the larger gyre.  I think this will stall for a bit then start creeping north before again turning wnw later today

[Radtechwxman]

What a mess. Lol. LLC running away from convection. Shear definitely still impacting Helene. I'm beginning to think it may not get its act together until the Gulf. 

[SnowGoose69]

HAFS-B smacks it well into the Yucatan lol

[Amped]

3 minutes ago, Radtechwxman said:

What a mess. Lol. LLC running away from convection. Shear definitely still impacting Helene. I'm beginning to think it may not get its act together until the Gulf. 

The band also still looking linear, and shows no sign of trying to bend or wrap around the center

[beanskip]

8 minutes ago, SnowGoose69 said:

HAFS-B smacks it well into the Yucatan lol

Yeah, the HAFS-A has it spending 12 HOURS over the Yucatan!

[hawkeye_wx]

The HAFS models are both now much weaker over the eastern gulf, likely mostly due to Helene being de-cored over the Yucatan.  A few hours over land is not a big deal, but twelve certainly is.

[beanskip]

14 minutes ago, SnowGoose69 said:

HAFS-B smacks it well into the Yucatan lol

That time spent over Yucatan led to a 43 mb increase in pressure effective 15z Thursday vs. the prior run. 

[beanskip]

4 minutes ago, hawkeye_wx said:

The HAFS models are both now much weaker over the eastern gulf, likely mostly due to Helene being de-cored over the Yucatan.

HMON super close to the same thing, but stays just offshore. 

[SnowGoose69]

The HAFS B comes in near the NHC track but its very weak, HMON appears it'll come in east of NHC track but way stronger

[Amped]

5 minutes ago, SnowGoose69 said:

The HAFS B comes in near the NHC track but its very weak, HMON appears it'll come in east of NHC track but way stronger

Global models have been in the 960s through 980s with the landfall pressure.. HAFS-B is pretty much in line with that this run.

[beanskip]

16 minutes ago, SnowGoose69 said:

The HAFS B comes in near the NHC track but its very weak, HMON appears it'll come in east of NHC track but way stronger

HAFS-B makes a late run at Cat 3 strength. Also a nightmare run for Tallahassee.

[GaWx]

12Z Euro is stronger at landfall than recent runs with 976 Thu evening Apalachee Bay. It gets to ATL just 8 hours later and weakens only to 981, which would be flirting with all-time record low SLP there.

[SnowGoose69]

Euro is pretty much NHC track, it seems to NOT get as close to the Yucatan as the 06Z Euro did

[beanskip]

Euro coming in stronger. Cat 2 (975 mb) at landfall. 

[Roger Smith]

I am expecting an over-performer (RI) and possibly cat-4 by 26-27 N (landfall 29N cat-3). East-west wobble factor (0.2-0.3 deg) is likely to play as max east displacements midnite, and max west mid-day, given moon's present orbital position. Strong n max declination peak at present will decrease over 3 days, it does add tidal range to coming period between F and new. 

[40/70 Benchmark]

1 minute ago, Roger Smith said:

I am expecting an over-performer (RI) and possibly cat-4 by 26-27 N (landfall 29N cat-3). East-west wobble factor (0.2-0.3 deg) is likely to play as max east displacements midnite, and max west mid-day, given moon's present orbital position. Strong n max declination peak at present will decrease over 3 days, it does add tidal range to coming period between F and new. 

Ah good 'ole Rog'...always playing it close to the vest-

[Floydbuster]

Helene is building, but I guess I'm honestly not impressed yet. I want to see a definitive, well formed low level center and get a handle on any possible Yucatan interaction. It doesn't have as much time as others to organize, so the longer it takes, the better for Florida.

[40/70 Benchmark]

2 minutes ago, Floydbuster said:

Helene is building, but I guess I'm honestly not impressed yet. I want to see a definitive, well formed low level center and get a handle on any possible Yucatan interaction. It doesn't have as much time as others to organize, so the longer it takes, the better for Florida.

Given the sheer size...surge will be lethal, but max winds may not ramp up as quickly as some pine for.

[AccuChris]

This is mesmerizing to watch in hi-def visible imagery


.

[hawkeye_wx]

Helene currently has an interesting presentation.  It has a well-defined center.  There is convection up-shear and down-shear, but nothing near the center.

[Radtechwxman]

3 minutes ago, hawkeye_wx said:

Helene currently has an interesting presentation.  It has a well-defined center.  There is convection up-shear, down-shear, and everywhere else, except near the center.

Basically nothing that will help it strengthen in the near term. Until convection pops over the center Helene going to be steady state or possibly weaken with exposed center. 

[BooneWX]

It appears in the most recent 3-4 frames, the coc has started a nnw motion. Whether that’s a wobble or an actual trend is too early to tell.

[Justin]

Outflow or arc clouds could be undercutting the center and causing wobbles to the S or SW too. 

[dan11295]

Significant interaction with the Yucatan is definitely possible here. Obviously that would result in a weaker system in the gulf. Just clipping the tip will have minimal impact, 6+ hours over land is another matter.

[wkd]

I love all of the input from hobbyist and non-tropical Mets, but my bet is with the forecasts provided by the mets in the NHC.  In the end they are usually not far off.