ATL: HELENE - Models

[aspen]

 https://x.com/AndyHazelton/status/1838616803301560816

They have trended weaker in the short term, based on what has loaded so far. The HAFS-B also shifted further south and has a landfall in the NE Yucatan as a still-organizing TS.

[TomballEd]

 https://x.com/AliciaMBentley/status/1833642228855533739

[BobHarlem]

HAFS-A also getting hung up on the Yucatan Peninsula. HMON is the only one that doesn't, but it still has problems settling on a center. (HWRF not out yet) Delays everything about a solid center by about 24 hours, today/tomorrow is going to be crazy in the discussion thread about where the center is. Good luck for anyone planning calls on things, this is going to be very difficult, something is going to majorly bust. I wouldn't count any area of the hurricane watch out, though. Worst thing is quite a few people may see it being blah tomorrow morning and ignore preparations.

[BIFF_THE_UNRULY]

Glad to see Total Tampa Death off the menu for now


*Not a forecast

[DunedinDave]

The "center running away naked" is a curveball for sure. I have no idea what this thing is going to do now and I'm sure the models are a bit confused as well. Crazy we're 48 hours from potential landfall and there are more questions than answers with this thing.

The Sad part is when it does get its act together, even if it's tomorrow morning, it could very well explode fast. I would not be shocked to see it go from 50 to 140 in 24 hours. Not saying it's going to happen and sure as hell hope it doesn't, but it wouldn't be unprecedented...especially after seeing what Katrina did in the Gulf some 20 years ago. That was like a bomb went in the Gulf.

[Travorum]

Wow, 90kt difference between 6z and 12z from HAFS-B, from a strong C5 to a tropical storm. There's a big deal of uncertainty in intensity down the line depending on if Helene shoots the gap or makes landfall in the Yucatan.

[FLLurker32]

Wow, 90kt difference between 6z and 12z from HAFS-B, from a strong C5 to a tropical storm. There's a big deal of uncertainty in intensity down the line depending on if Helene shoots the gap or makes landfall in the Yucatan.

It inched slightly more west too.

[DunedinDave]

Hurricane models definitely trending west while the computer models trending east. Today's the day the models are supposed to come together not grow apart.

[aspen]

Sheared Cat 1 on both the HAFS-A and B. It never fully recovers after land interaction with the Yucatan.

The hurricane models’ back-and-forth continues. Inb4 the 18z runs have a Cat 5 again.

[FLLurker32]

HAFS-A 12z tours the Yucatán a bit then takes its messy drunk self on into Steinhatchee at 973mb. Huge change on intensity. Where it pulls north in comparison to the Yucatán has a huge impact.

[ElectricStorm]

Looks like 12z hurricane models with new data are seeing quite a bit of shear in the gulf compared to past runs. HMON mostly avoids land interaction but still doesn't become a major, with a weak west side. Something to watch for on the next cycle

[BobHarlem]

HAFS-B 961mb at landfall (barely typical cat 3 pressures but not strong as max wind), HAFS-B about 968 (Cat 2 typical pressure but not strong as max wind), HMON 942mb (pushing into Cat 4 territory pressure wise but not strong as max wind), despite the weird early part. Weird effect of the wind may actually be stronger after landfall than during, at least in the short term.

The early struggles make me doubt the whole run though, and the pressures make me think it's underdoing the wind.

[mcheer23]

HAFS-B 961mb at landfall (barely typical cat 3 pressures), HAFS-B about 968 (Cat 2 typical pressure), HMON 942mb (pushing into Cat 4 territory), despite the weird early part.

Really not sure what to think about the HAFS...drifts onto the Yucatan...that's the reason for the higher pressures.
HWRF seems like its headed toward the 940's just like the HMON

[FLLurker32]

Hurricane models definitely trending west while the computer models trending east. Today's the day the models are supposed to come together not grow apart.

There seems to always be a run or two like this before these potential RI storms get their stuff together. Models still very much have a hard time handling just how the storm is going to set up to handle all that energy available.

[toad strangler]

Hurricane models definitely trending west while the computer models trending east. Today's the day the models are supposed to come together not grow apart.

Just me but I would favor globals for track and hurricane models for structure. Generally..

[ElectricStorm]

HAFS-B 961mb at landfall (barely typical cat 3 pressures but not strong as max wind), HAFS-B about 968 (Cat 2 typical pressure but not strong as max wind), HMON 942mb (pushing into Cat 4 territory pressure wise but not strong as max wind), despite the weird early part.

Look at the 10m winds though, HMON has 94kts (Cat 2) and both HAFS barely have a Cat 1. With broad systems like this you can have a lower than usual pressure compared to winds.

[FLLurker32]

Hurricane models definitely trending west while the computer models trending east. Today's the day the models are supposed to come together not grow apart.

Just me but I would favor globals for track and hurricane models for structure. Generally..

I know there’s a lot of recon data in this suite, but do you happen to know how much/if any broader atmospheric data was plugged into 12z?

[DunedinDave]

HWRF hasn’t changed much. Has it near 940 mbs as it approaches Steinhatchee. Will be interesting to see if there are any changes to ensembles as we get to 18z.

[Steve]

CMC @ 975 heading towards a landfall east of Apalachicola (Cat 2ish)

https://www.tropicaltidbits.com/analysi ... 2412&fh=60

Kind of clips the NE Yucatan but only part of the center does.

[lsuhurricane]

12z Euro run seems pretty locked in on a Cat 2 at landfall. Realistic projection here.