ATL: HELENE - Models

[DunedinDave]

18z HWRF has a massive shift in timing; went from landfall at 15z on Thursday to not even at Tampa's latitude.

This entire 18z suite just seems off regarding data ingestion. 00z we'll see if things start to change a bit.

It seems like the operational models want to go east and the Hurricane ones west. Not sure which ones are more accurate. 72 hours out and still a lot of uncertainty.

[Woofde]

HAFS 18z runs are starting now. Both versions have dramatically held back on development and show a near due west track compared to their bonkers 12z runs. Something tells me that these runs are iffy, so it’s probably best to wait for the 00z runs that’ll have recon data.

https://i.imgur.com/mh0hZKv.png
https://i.imgur.com/9NiWAAO.png

https://i.imgur.com/tWG7MX9.png
https://i.imgur.com/XMhNkjA.png

Went from Rita/Wilma 2.0 to disorganized slop between two runs. Yeah we’re gonna need a defined LLC for these to be consistent and reliable.

These super weak 18z runs don’t seem particularly likely with the gradual consoldiation we’re seeing.

It’s interesting because the large, disorganized slop was where we started a few days ago.

We still could easily go back to looking at a sloppy Cat 1. Until we leave the formative stages of TC development intensity will be shifting rapidly every run

[WiscoWx02]

Not sold on the weaker 18z runs. We don't have a consolidated center yet. In fact, over the last hour it appears another reformation of where a center may try to form is underway, bringing the center closer to the deep convection further east. Yes recon got ingested but what use is it other than environmental sampling around the storm if the center it was surveying no longer exists and it in a better spot now than it was before? Point is, satellite is our best friend for now until a concrete center forms and recon can get in there and sample it.
There is also the note of Hurricane John...personally I think John's outflow is so small and limited due to it's small size and limited life span that it probably isn't going to end up effecting 09L all that much, especially once 09L starts lifting north. If the forward speed of 09L isn't too quick, then I still foresee it becoming a major in the Gulf.

I am usually bearish on storms, but I don't feel bearish about this one, it could be trouble

[chris_fit]

Can't post a pic right now but the 18z EPS show a notable shift east compared to the 12z EPS.

[cycloneye]

 https://x.com/AndyHazelton/status/1838373193792266256

[Blown Away]

Can't post a pic right now but the 18z EPS show a notable shift east compared to the 12z EPS.

What source are you referencing?

[eastcoastFL]

The 18z HWRF is moving with some serious speed at the end of the run. It makes landfall just west of the big bend in just 75 hours. Around this time Thurs.

[Blinhart]

HAFS 18z runs are starting now. Both versions have dramatically held back on development and show a near due west track compared to their bonkers 12z runs. Something tells me that these runs are iffy, so it’s probably best to wait for the 00z runs that’ll have recon data.

https://i.imgur.com/mh0hZKv.png
https://i.imgur.com/9NiWAAO.png

https://i.imgur.com/tWG7MX9.png
https://i.imgur.com/XMhNkjA.png

These actually look more appropriate

[sasha_B]

HAFS 18z runs are starting now. Both versions have dramatically held back on development and show a near due west track compared to their bonkers 12z runs. Something tells me that these runs are iffy, so it’s probably best to wait for the 00z runs that’ll have recon data.

https://i.imgur.com/mh0hZKv.png
https://i.imgur.com/9NiWAAO.png

https://i.imgur.com/tWG7MX9.png
https://i.imgur.com/XMhNkjA.png

These actually look more appropriate

I'm not sure...obviously the 12z runs were absurdly overenthusiastic about intensification, but I doubt that a system that's been organising more or less steadily all day will end up remaining a complete mess for the next 24-36 hours like the 18z runs (especially HAFS) are suggesting. Seems reasonable to say that the eventual outcome will fall somewhere between these extremes.

[chris_fit]

Can't post a pic right now but the 18z EPS show a notable shift east compared to the 12z EPS.

What source are you referencing?

18z



And here's the 12z

[Hammy]

18z HWRF has a massive shift in timing; went from landfall at 15z on Thursday to not even at Tampa's latitude.

This entire 18z suite just seems off regarding data ingestion. 00z we'll see if things start to change a bit.

It seems like the operational models want to go east and the Hurricane ones west. Not sure which ones are more accurate. 72 hours out and still a lot of uncertainty.

NAM is going west too, seems like the mesoscale ones in general want to trend that way.

[Steve]

Early cycles 00z
https://hurricanes.ral.ucar.edu/realtim ... _early.png

Late Cycle 18z
https://hurricanes.ral.ucar.edu/realtim ... k_late.png

Early cycle intensity 00z
https://hurricanes.ral.ucar.edu/realtim ... _early.png

Late cycle 18z EPS
https://hurricanes.ral.ucar.edu/realtim ... l_late.png

Looks like it’s all coalescing around or just east of Apalachicola mostly with perhaps Panama City being the farthest west. With a few deviations, this has been the target zone for a couple of days. We are within the time frame where models are usually pretty damn close. That’s not to say there isn’t a chance this could go a bit east or west. But it’s likely not going to deviate that much from what we are seeing now

[Blown Away]

Today’s models are based on that naked weak circulation on the W side of the convection that appears dissipated now and it may be correct, so the farther W movement in next 36-48 hours and weakening trend downstream would be correct. Clearly tonight if there is an LLC, it will be somewhere near the convection to the east. IMO, 00z models will be the clincher on a Big Bend landfall or something E or W of that area. JMHO

[DunedinDave]

Early cycles 00z
https://hurricanes.ral.ucar.edu/realtim ... _early.png

Late Cycle 18z
https://hurricanes.ral.ucar.edu/realtim ... k_late.png

Early cycle intensity 00z
https://hurricanes.ral.ucar.edu/realtim ... _early.png

Late cycle 18z EPS
https://hurricanes.ral.ucar.edu/realtim ... l_late.png

Looks like it’s all coalescing around or just east of Apalachicola mostly with perhaps Panama City being the farthest west. With a few deviations, this has been the target zone for a couple of days. We are within the time frame where models are usually pretty damn close. That’s not to say there isn’t a chance this could go a bit east or west. But it’s likely not going to deviate that much from what we are seeing now

Is the center right on those models? That looks like old one. Center seems to be reforming just south of the Caymans right now. Those models have the center far west of that/

[Ken711]

Early cycles 00z
https://hurricanes.ral.ucar.edu/realtim ... _early.png

Late Cycle 18z
https://hurricanes.ral.ucar.edu/realtim ... k_late.png

Early cycle intensity 00z
https://hurricanes.ral.ucar.edu/realtim ... _early.png

Late cycle 18z EPS
https://hurricanes.ral.ucar.edu/realtim ... l_late.png

Looks like it’s all coalescing around or just east of Apalachicola mostly with perhaps Panama City being the farthest west. With a few deviations, this has been the target zone for a couple of days. We are within the time frame where models are usually pretty damn close. That’s not to say there isn’t a chance this could go a bit east or west. But it’s likely not going to deviate that much from what we are seeing now

What is causing the system to curve to the west after it makes landfall and continues into Georgia?

[chris_fit]

Early cycles 00z
https://hurricanes.ral.ucar.edu/realtim ... _early.png

Late Cycle 18z
https://hurricanes.ral.ucar.edu/realtim ... k_late.png

Early cycle intensity 00z
https://hurricanes.ral.ucar.edu/realtim ... _early.png

Late cycle 18z EPS
https://hurricanes.ral.ucar.edu/realtim ... l_late.png

Looks like it’s all coalescing around or just east of Apalachicola mostly with perhaps Panama City being the farthest west. With a few deviations, this has been the target zone for a couple of days. We are within the time frame where models are usually pretty damn close. That’s not to say there isn’t a chance this could go a bit east or west. But it’s likely not going to deviate that much from what we are seeing now

Why are the 18z EPS you posted different than the 18z EPS I posted few min earlier?

[eastcoastFL]

Early cycles 00z
https://hurricanes.ral.ucar.edu/realtim ... _early.png

Late Cycle 18z
https://hurricanes.ral.ucar.edu/realtim ... k_late.png

Early cycle intensity 00z
https://hurricanes.ral.ucar.edu/realtim ... _early.png

Late cycle 18z EPS
https://hurricanes.ral.ucar.edu/realtim ... l_late.png

Looks like it’s all coalescing around or just east of Apalachicola mostly with perhaps Panama City being the farthest west. With a few deviations, this has been the target zone for a couple of days. We are within the time frame where models are usually pretty damn close. That’s not to say there isn’t a chance this could go a bit east or west. But it’s likely not going to deviate that much from what we are seeing now

What is causing the system to curve to the west after it makes landfall and continues into Georgia?

Looks like high pressure to it's east.

[Spacecoast]

Early cycles 00z
https://hurricanes.ral.ucar.edu/realtim ... _early.png

Late Cycle 18z
https://hurricanes.ral.ucar.edu/realtim ... k_late.png

Early cycle intensity 00z
https://hurricanes.ral.ucar.edu/realtim ... _early.png

Late cycle 18z EPS
https://hurricanes.ral.ucar.edu/realtim ... l_late.png

Looks like it’s all coalescing around or just east of Apalachicola mostly with perhaps Panama City being the farthest west. With a few deviations, this has been the target zone for a couple of days. We are within the time frame where models are usually pretty damn close. That’s not to say there isn’t a chance this could go a bit east or west. But it’s likely not going to deviate that much from what we are seeing now

Why are the 18z EPS you posted different than the 18z EPS I posted few min earlier?

It looks like what was labeled 'EPS' is really GEFS.

[Kohlecane]

One thought is that if John inhibits this in the near term, that won't be an issue once it gets north of about 20N, and then if it waits to start rapid intensification, it won't have time to go into an ERC so it could be intensifying (rapidly) right up to landfall...

I think you brought this up a few days ago, kudos!

[otowntiger]

Can't post a pic right now but the 18z EPS show a notable shift east compared to the 12z EPS.

What source are you referencing?

18z
https://i.imgur.com/0nLrFT0.png


And here's the 12z
https://i.imgur.com/9gTMK56.png

much more notable is the significant weakening since the last run.