ATL: SAM - Models

[Category5Kaiju]

The HMON is on crack. It sends 98L all the way down to 7N and has rapid genesis within 48 hours, likely due to getting within the strip of 29C SSTs below 10N. 98L doesn’t get back to 10N until Thursday night around 35-37W, and by that time, it has already become a hurricane.

Is it even possible for an Atlantic TC to close off that far south? I think it would be too buried in the ITCZ to develop a closed circulation.

Yes; Allen and Ivan show how getting potent hurricanes at very low latitudes in the MDR can still happen

[kevin]

12z Euro... don't



Still most likely OTS (from a US perspective), but could still be trouble for the Caribbean and Bermuda in particular. If it weren't for Euro's previous forecasts busting so hard I'd be very confident about this one becoming a potent hurricane. But since the Euro has been a bit of hit-or-miss lately I'll keep my expectations in check. Also September 20 - 27 seems to be the last time period in which big MDR storms can form (Lili, Flora and Inez) so if 2021 really wants a big MDR storm (besides Larry) this might be its last chance.

[AutoPenalti]

Uh...

[Iceresistance]

Uh...

https://i.imgur.com/1T5FOKq.gif

*Flashbacks to tracking Irma & Jose in 2017*

[AutoPenalti]

Uh...

https://i.imgur.com/1T5FOKq.gif

*Flashbacks to tracking Irma & Jose in 2017*

If that trough lifts out quick enough, it's a problem.

[Category5Kaiju]

Uh...

https://i.imgur.com/1T5FOKq.gif

Cease Sam, cease.

[kevin]

Euro+240 . There's an escape hatch for 98L on this run so it'll probably go OTS if it went beyond +240, but the ridge is building back a bit at the end. The good thing is that it's at +240 and not +96 and let's hope it stays that way. Especially after last year's struggle with the Euro to even form storms I kind of humanized the model as a 'calm, collected, experienced storm2k user who almost never joins hype bandwagons early', but now it feels more like happy hour GFS .

[tolakram]

[Iceresistance]

Just misses to the North, but that is also trending like Andrew 1992, Look out!



There is a East Coast Trough like the 12z GFS, it may be similar to Earl 2010

[aspen]

The HMON is on crack. It sends 98L all the way down to 7N and has rapid genesis within 48 hours, likely due to getting within the strip of 29C SSTs below 10N. 98L doesn’t get back to 10N until Thursday night around 35-37W, and by that time, it has already become a hurricane.

Is it even possible for an Atlantic TC to close off that far south? I think it would be too buried in the ITCZ to develop a closed circulation.

Yes; Allen and Ivan show how getting potent hurricanes at very low latitudes in the MDR can still happen

Allen was further north than either Ivan or 98L. It would require some very favorable conditions besides those warm SSTs at 5-10N for 98L to bomb out at such a low latitude like Ivan did, although it could have a better chance if it remains at 10.5-12N by the time it reaches 45W on Saturday. SSTs will be nearly 30C then.

The HWRF and HMON have very different ideas on what 98L/Sam will be like at the end of the week. The HWRF is close to the global models and shows a strong TS getting its core organized on Friday, while the HMON has a mature Category 3 major hurricane. The former is much more realistic at this stage unless we see rapid development tomorrow and Wednesday.

[tolakram]

It won't make it through the front / shear zone. I suspect unless something radically changes it will ride up the front and stay off the coast.

[SFLcane]

Andrew? It’s 2021 lol.. Not even close.

More like batter up!

[kevin]

Cue the 'this is where the fun begins' meme. This might be the MDR storm that we thought Peter or Rosa would've been. Hopefully it'll go OTS and be a nice ACE machine. While development is of course very likely, I'll await the ensemble & GFS to see what the general consensus is. It is a very complex situation with both Peter and Rose impacting its future path so it's not just modelling 1 storm, but modelling 3 storms and how they impact each other. I suspect we won't have a good agreement between models for now, at least not at the same level as we usually have for (future) TCs at this point.

[JPmia]

That would be an early cold front for south Florida at that time of year wouldn’t it?

[AutoPenalti]

That would be an early cold front for south Florida at that time of year wouldn’t it?

Well it's the first day of October so why not.

[otowntiger]

It won't make it through the front / shear zone. I suspect unless something radically changes it will ride up the front and stay off the coast.

https://i.imgur.com/NLQfTlD.png

https://i.imgur.com/2fKIOfU.png

Agreed. With that particular synoptic pattern there is no way the storm would get much further west than where its show at that time period. Of course the synoptic set-up may not verify, but the storm location/strength at the point could also be radically different in 240 hours.

[ColdMiser123]

Very far out, so entirely possible this is the Euro's long range amplified bias coming into play here, and I'm expecting EPS to show this at 12z.

That being said, the amount of ridging in the north Atlantic is quite something on the Euro. Pieces are not far away at all from a Northeast hit this run. Trough probably just has to be tad farther west.

[Teban54]

The HMON is on crack. It sends 98L all the way down to 7N and has rapid genesis within 48 hours, likely due to getting within the strip of 29C SSTs below 10N. 98L doesn’t get back to 10N until Thursday night around 35-37W, and by that time, it has already become a hurricane.

Is it even possible for an Atlantic TC to close off that far south? I think it would be too buried in the ITCZ to develop a closed circulation.

Southernmost TDs below 8N:
- Isidore 1990: became a TD at 7.2N 23.4W, and a TS at 10.0N 32.7W
- Kirk 2018: became a TD at 7.7N 21.8W, and a TS at 8.1N, 22.9W
- #3 1902: became a TS at 7.7N 30.8W
- TD11 1968: became a TD at 7.9N 43.1W
- Fran 1990: southernmost point is at 7.9N 44.6W as a TD (formed at 9.0N 32.1W); dissipated after that, then reformed at 8.7N 51.1W, and became a TS at 9.0N 53.6W

Hurricane Three 1902 is the only storm on record to be a TS south of 8N, as a 35 kt minimum TS. The maximum intensity for any storm south of 9N is 50 kt (Ivan 2004 and #5 1878).

12z HMON has 98L crossing the 8N line at 32.5W almost as a Cat 1. So we can safely say it's unrealistic.

[aspen]

Andrew? It’s 2021 lol.. Not even close.

More like batter up!

https://i.postimg.cc/fR817g21/8-B2-E6-A8-B-20-F9-4-BFD-8-F75-F35-C44606-FB2.gif

https://i.postimg.cc/FRVycwGL/F4-A0-CFB3-4724-4515-A7-BD-07-B7-EFDF0-A9-C.gif

That would be a nice big OTS major, albeit quite uncomfortably close to the Greater Antilles, Bermuda, and US East Coast. Those waters just north of the GAs are broiling and are still rather untapped because Peter is too weak to suck them up.

[AutoPenalti]

Ridge would need to be further south for any Andrew scenarios...