ATL: HELENE - Models

[FLLurker32]

18Z running.

https://i.imgur.com/YVeO24n.png

Initialized pretty close. This will be interesting.

Looks to get still close to Yucatán ( don’t see it but we will see) but also have a stronger right hand turn that puts Helene into Cedar Key.

Earlier today I noticed the 12z spaghetti models, while all were far to the west, showed the models that got closest to the Yucatán seemed to favor a more south/eastern impact on the big bend.

[FLLurker32]

GFS still showing organizational issues. GFS is pretty good in this area, is it right?

https://i.imgur.com/p0BWFmL.png

NHC mentioned the possibility for some light sheer to hit it just before landfall. That may be what it’s showing with the structural issues there.

[MJGarrison]

The 18Z GFS shows Helene exiting the Yucatán channel east of the 12Z, but landfall in Florida ends up just a bit west.


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[DunedinDave]

The 18z GFS is ever so slightly EAST of its track when parallel with Tampa/St. Pete and approaching the west coast but actually now slightly WEST from the 12z when it comes to landfall.

I'm not sure what's causing this (maybe the experts can explain this better) but the GFS believes this thing is going turn more northerly, which obviously will spare places from Cedar Key to say Tarpon Springs.

[Travorum]

The 18z GFS is ever so slightly EAST of its track when parallel with Tampa/St. Pete and approaching the west coast but actually now slightly WEST from the 12z when it comes to landfall.

I'm not sure what's causing this (maybe the experts can explain this better) but the GFS believes this thing is going turn more northerly, which obviously will spare places from Cedar Key to say Tarpon Springs.

Not an expert at all but looking at the 500mb level it seems like the trough is moving across the US faster but the high pressure to the southeast builds in stronger and slightly more west. The net result of that looks like Helene gets a combined push+pull to the north in the last 6 hours before landfall, therefore making landfall slightly west in the big bend.

[DunedinDave]

She's about to explode. I have a feeling we're going to wake up in the morning to a monster.

[Keldeo1997]

20kt / 12h 14.1% 17.8% 16.0%
25kt / 24h 61.9% 73.3% 67.6%
30kt / 24h 41.8% 57.3% 49.5%
35kt / 24h 33.0% 56.8% 44.9%
40kt / 24h 8.0% 56.8% 32.4%
45kt / 36h 56.5% 80.4% 68.4%
55kt / 36h 0.0% 65.4% 32.7%
55kt / 48h 52.1% 67.1% 59.6%
70kt / 48h 45.1% 56.8% 50.9%
65kt / 72h 55.5% 16.9% 36.2%

Current SHIPS. The Eyebrow raiser here is what I have in bold. At around a coinflip to have 130kts at around landfall time.

[kevin]

HAFS-B once again has way too much west motion and landfalls in Yucatan. It's current position of Helene (in between the 21z and 00z data points) is already off with about 0.4 degrees west bias. Despite this it's much more intense so far than 12z, 968 mb at +33 hr compared to 986 mb in the 12z run at that point in time.

[BobHarlem]

Low pressures: HMON dipping into the 930s again (So far). HAFS-B around 945 before landfall. HAFS-A gets to 933mb right before it reaches Steinhatchee. All seem stronger this run over the 12z.

[aspen]

HAFS-B once again has way too much west motion and landfalls in Yucatan. It's current position of Helene (in between the 21z and 00z data points) is already off with about 0.4 degrees west bias. Despite this it's much more intense so far than 12z, 968 mb at +33 hr compared to 986 mb in the 12z run at that point in time.

HAFS-B also still seems to disrupt Helene a bit with the Yucatan. It’s never able to form a clean eyewall afterwards, just tons of competing bands.

[tolakram]

Not sure when I con runs, but here is the 18Z

[kevin]

Just the blend this time since I don't have much time. Of course stronger than 12z with peak intensities of 941mb/98kt for HWRF, 936mb/121kt for HMON, 933mb/132kt for HAFS-A and 945mb/116kt for HAFS-B. Note that the HAFS models still show landfall on Yucatan.

Blend
PEAK: 939 mb @ 54 hrs | 107 kt @ 51 hrs
hr / pressure (mb) / wind (kt)
00 / 998 / 41
06 / 991 / 54
12 / 982 / 58
18 / 978 / 68 - C1
24 / 976 / 58
30 / 971 / 71
36 / 958 / 93 - C2
42 / 951 / 91
48 / 943 / 106 - C3
51 / 940 / 107
54 / 939 / 106 - landfall
57 / 944 / 76

[869MB]

18Z running.

https://i.imgur.com/YVeO24n.png

Helene appears to be slightly ahead of schedule regarding what this 18Z GFS run depicts concerning intensity...

NOAA2 Mission #7 into HELENE
Type: Low-level Reconnaissance | Status: In Storm

As of 23:33 UTC Sep 24, 2024:
Aircraft Position: 19.62°N 85.17°W
Bearing: 270° at 226 kt
Altitude: 3090 gpm
Peak 10-second Wind: 16 kt at 217°
Extrapolated Sea-level Pressure: 991.0 mb

[caneman]

18Z running.

https://i.imgur.com/YVeO24n.png

Helene appears to be slightly ahead of schedule regarding what this 18Z GFS run depicts concerning intensity...

NOAA2 Mission #7 into HELENE
Type: Low-level Reconnaissance | Status: In Storm

As of 23:33 UTC Sep 24, 2024:
Aircraft Position: 19.62°N 85.17°W
Bearing: 270° at 226 kt
Altitude: 3090 gpm
Peak 10-second Wind: 16 kt at 217°
Extrapolated Sea-level Pressure: 991.0 mb

If that heading stays true, the nhc had it getting to 86. Would be a miss of 60 miles which would lend credence to icons cedar key hit. Something to watch. If that were to happen, storm surge values would go way up for the Tampa Bay area

[gatorcane]

Looks like the 18Z ECMWF shifted slightly east of the 12Z ECMWF on its closest approach to the Tampa area. Also has a stronger cyclone, with the highest 850MB winds on the east side:

[tolakram]

Hurricane model animations

[Bocadude85]

Looks like the 18Z ECMWF shifted slightly east of the 12Z ECMWF on its closest approach to the Tampa area. Also has a stronger cyclone, with the highest 850MB winds on the east side:

https://i.postimg.cc/WbDNq0fJ/ec-fast-mslp-uv850-watl-3.png

It did shift east, was just looking at it. Hopefully not the start of a trend. The 0z cycle will be interesting.

[chaser1]

Has anyone calculated how many miles Helene is projected to be from Tampa Bay based on the EURO (or any other model run)?

The storm is certainly looking a good deal more healthy this evening. I'm still not hearing or seeing anything that would lead me to consider any increased risk for a forecast track that would bring the core any closer to the Tampa to Clearwater area thus far. Granted, things could change.

[BIFF_THE_UNRULY]

Has anyone calculated how many miles Helene is projected to be from Tampa Bay based on the EURO (or any other model run)?

The storm is certainly looking a good deal more healthy this evening. I'm still not hearing or seeing anything that would lead me to consider any increased risk for a forecast track that would bring the core any closer to the Tampa to Clearwater area thus far. Granted, things could change.

Looks to be about 70 miles give or take 10

[gatorcane]

The GFS track has an intensifying hurricane headed NE for the west coast of Florida / Tampa area but turns NNE just in time, certainly this kind of track will be a bit of a nailbiter the day of the event: