ATL: LEE - Models

[TimSmith]

Very good point, and also to add to that is the fact that these models generally work as solutions to mathematical differential equations which are very susceptible to small changes in their initial conditions. i.e., a small change to the data fed in regarding the current structure of the storm and/or if it develops a lot more or less as it tracks west over the next few days can have huge impacts on the longer range. ...

Exactly why ensembles were developed...Small changes in the initial conditions (perturbations) are introduced to make up for the fact that the current structure can never be measured exactly. This is due to measurement errors, and equipment tolerances.

Yes, those help and I expect as computing power continues to grow we will gain more information, but we will always have a limitation. IMHO 3-5 days forecasting is doable but with quite a bit of error, beyond 5 is very high uncertainty

[LarryWx]

The inferior JMA (12Z), unlike the worrisome run from 24 hours ago going into the Caribbean to just S of the DR, is ~500 miles NE of that run and is recurving near 65W.

[kevin]

My experience with the globals (euro, gfs etc) is that they always underestimate (long-term) intensity by quite a bit. This can range from 10 - 20 mb when a storm is well-defined to even 40+ mb in sloppy systems. F.e. even just 72 hours before landfall GFS had Idalia at 960 mb and ECMWF at a measly 981 mb (reality was 940 mb of course). Which is why we often switch to the hurricane models and of course live observations (recon, ADT) during periods of RI. The globals are then often more used for steering than for intensity. So a 915 mb from a long-term Euro run is definitely worthy of a as in potential open ocean record crazy. Can't recall the last time I've seen a sub-920 operational run for the Euro in the Atlantic.

[aspen]

Dang it’s not every day the Euro spits out a 917mb hurricane in the Atlantic.

[kevin]

This might be the craziest Atlantic Euro ensemble I've ever seen, it's just all pink...

[kevin]

Just one member of one ensemble, I know, but I've never seen sub-900 on the Euro. You're seeing correctly, it's saying 897 mb.

[mantis83]

Dang it’s not every day the Euro spits out a 917mb hurricane in the Atlantic.

i actually saw 915mb on pivotal. i hope the planes can get in there when it's at the peak of it's powers

[SouthDadeFish]

I saw at least two EPS members with a central pressure below 900 mb. That's mind-blowing for an ATL TC, especially one that's not even a TC yet. The ceiling for this system is about as high as any I've seen in this basin. Storm structure will likely dictate the peak intensity, but this will be quite a show over the next week or so.

[ScottNAtlanta]

I still don't think the models are handling the remnants of Idalia properly. Both the GFS and Euro seem to want to loop it back west yet looking at the satellite it's going pretty steadily NNE, and not all that slowly. Until they figure that out, the models aren't going to be worth much. They have both been terrible handling Idalia since it became post-tropical

[Spacecoast]

Model tracks....

[Hurrilurker]

That 917MB deserves a . Sharp turn NNE with some “weakening” after that

Yeah, that turn seems CRAZY sharp for such an intense system (917 mb). I don't remember ever seeing that, although it's probably happened.

[NotSparta]

That ECMWF/EPS suite this cycle is about the strongest I can remember for anything in the Atlantic, particularly an invest. This definitely has the potential to be quite impressive, hopefully the troughing is strong enough to keep it away from land

[Category5Kaiju]

That 917MB deserves a . Sharp turn NNE with some “weakening” after that

Yeah, that turn seems CRAZY sharp for such an intense system (917 mb). I don't remember ever seeing that, although it's probably happened.

Two notable Cape Verde systems that did something like that are Edouard 1996 and the 1938 Yankee Clipper. In the grand scheme of things though, I'd have to imagine that sharp turns like that for intense systems aren't exactly very common, with many recurves normally happening more gradually

[zzzh]

That ECMWF/EPS suite this cycle is about the strongest I can remember for anything in the Atlantic, particularly an invest. This definitely has the potential to be quite impressive, hopefully the troughing is strong enough to keep it away from land

Part of the reason why EPS is so strong is that it got upgraded this June. I doubt the old EPS would be this crazy

[SconnieCane]

Surprisingly, the award for Nuclear Hurricane Model as of today's 12Z runs goes not to the HWRF but the HAFS-B, which gets it down to 917 MB and still dropping at the end of the run.

[Iceresistance]

I saw at least two EPS members with a central pressure below 900 mb. That's mind-blowing for an ATL TC, especially one that's not even a TC yet. The ceiling for this system is about as high as any I've seen in this basin. Storm structure will likely dictate the peak intensity, but this will be quite a show over the next week or so.

Do you have the opportunity to have a picture for that?

[Hayabusa]

I saw at least two EPS members with a central pressure below 900 mb. That's mind-blowing for an ATL TC, especially one that's not even a TC yet. The ceiling for this system is about as high as any I've seen in this basin. Storm structure will likely dictate the peak intensity, but this will be quite a show over the next week or so.

Do you have the opportunity to have a picture for that?

[Iceresistance]

Thanks to Hayabusa, I located the other sub-900 member based on his map.


https://s11.gifyu.com/images/Sg5Gk.png

[floridasun]

i got good feeling will move alway from usa only beruma may need watch it runs been showing turns for past few days

[Stratton23]

Once again the SE coast is definitely in play, especially areas around New England, very very and i mean VERY complicated steering pattern is shaping up, folks up in the New England area should be watching this, do not think the trough is going to be strong enough to push it out to sea