ATL: SAM - Remnants - Discussion

[aspen]

130kt FL, 941.6mb

Quite a significant pressure drop despite the double wind maxima. The standard 90% FL-to-surface conversion factor supports a 115-120 kt Cat 4.

[Owasso]

Dropsonde supports 945mb.

[Category5Kaiju]

Looks like we may be in to see a sizeable secondary peak in Sam's strength; also, given the amount of time this storm is expected to remain as a major hurricane strength (let alone Cat 4), this is going to accumulate a LOT of ACE by the end.

[Owasso]

18L SAM 210929 1800 19.8N 57.3W ATL 115 945

[tolakram]

 https://twitter.com/TropicalTidbits/status/1443279109904158722

[Owasso]

Recon reported hail in the Southwestern Eyewall.

[DioBrando]

Recon reported hail in the Southwestern Eyewall.

https://i.postimg.cc/MTBD63vY/A8-FD4-F84-9-E84-4-EFA-8-D0-A-8790-AE4281-B1.jpg

HAIL in the caribbean? I've never heard of that... does this mean ET transition is imminent?

[Owasso]

 https://twitter.com/philklotzbach/status/1443285473095421954

[sikkar]

Recon reported hail in the Southwestern Eyewall.

https://i.postimg.cc/MTBD63vY/A8-FD4-F84-9-E84-4-EFA-8-D0-A-8790-AE4281-B1.jpg

What's the significance of this? Intensification?

[Owasso]

Recon reported hail in the Southwestern Eyewall.

https://i.postimg.cc/MTBD63vY/A8-FD4-F84-9-E84-4-EFA-8-D0-A-8790-AE4281-B1.jpg

What's the significance of this? Intensification?

I think it’s something rare, I couldn’t say that it is a sign of intensification, I just find that hail in a hurricane’s eyewall is a rare event.

[Iceresistance]

Recon reported hail in the Southwestern Eyewall.

https://i.postimg.cc/MTBD63vY/A8-FD4-F84-9-E84-4-EFA-8-D0-A-8790-AE4281-B1.jpg

HAIL in the caribbean? I've never heard of that... does this mean ET transition is imminent?

It's getting stronger, Iota in 2020 had Hail in the SW Eyewall as well . . .

[kevin]

As of now Sam has been a major hurricane continuously for 105 hours. And it is forecasted to remain a MH for at least another 68 hours, which would bring its total to 173 hours. I know this streak might be broken in post-analysis if its intensity is set at a high-end cat 2 just after that first EWRC, but for now at least 105 hours with a potential for 170+ is incredible. I can't recall the last time that happened, must've been one of those 2017 monsters. I haven't checked all storms, but the absolute record has to be the 1899 San Ciriaco hurricane right? That one was a MH for roughly 270 hours.

[wxman57]

Here are the results from each of the four eyewall passes. Note that when the plane uses SFMR, the Fl to surface conversion is not needed/used. If the winds are measured at 100-105 kts, then that's what the plane found at the surface at that time and in that exact location. It doesn't mean that winds were stronger or weaker elsewhere, it's just the data along the flight path over a small section of the ocean. In this case, one could argue that there may be stronger surface winds than the 103 kts measured by recon, but that would be just a guess. That said, the NHC will likely go with 115 kts to go along with their previous reasoning that there may be stronger winds present. Plane is now climbing and the mission is over.

[wxman57]

As of now Sam has been a major hurricane continuously for 105 hours. And it is forecasted to remain a MH for at least another 68 hours, which would bring its total to 173 hours. I know this streak might be broken in post-analysis if its intensity is set at a high-end cat 2 just after that first EWRC, but for now at least 105 hours with a potential for 170+ is incredible. I can't recall the last time that happened, must've been one of those 2017 monsters. I haven't checked all storms, but the absolute record has to be the 1899 San Ciriaco hurricane right? That one was a MH for roughly 270 hours.

There's a good reason why Sam is lasting longer as a major hurricane - steering currents in the deep tropics are rather weak. Sam has been moving at a forward speed of less than 10 kts, which is rather slow for that region. The slow movement is giving it more time over warm water with lower wind shear. Typical forward speed in the region is 14-18 kts.

Oh, I'd be careful about being too trusting of intensity records from the 1800s.

[Iceresistance]

Absolutely Stunning

[Hypercane_Kyle]

Absolutely Stunning

https://s9.gifyu.com/images/19791629.gif

Nearly perfect outflow structure. Sam may make another run at Category 5 should this EWRC finish up soon.

[Sciencerocks]

[kevin]

Sam looks amazing right now, great structure and ventilation. If the eye can clear out we might have a real stunner.

[jconsor]

 https://twitter.com/yconsor/status/1443298344688828422

[grapealcoholic]

Eye has been warming, so I would guess the ERC is close to finishing