ATL: CHANTAL - Post-Tropical - Discussion

[syfr]

Oh yeah, she’s on her way for sure.

This is my first post of the season. Good to be back. Happy 4th everyone!

She came to be quickly!!

First post for me in 2025 too. Everyone have a great 4th!

[Sciencerocks]

[MEANINGLESS_NUMBERS]

That's a good-looking invest

[Sciencerocks]

Better then Andrea or barry ever looked! Probably PTC Advisories soon or a full upgrade depending on what the recon finds.

[cycloneye]

 https://x.com/iCyclone/status/1941191472830992857

[Sciencerocks]

26 knt westerly winds. 99% certain that it is closed. I'd say it is deserving of TD3 and probably Ts chantal depending on what they find in stronger quads.

[tropicwatch]

Recon reporting several 40mph and higher surface winds.

[cycloneye]

Peak Flight-Level Winds: 33kt at 18:24z

[Ian2401]

Easily at least a depression at this point, FL winds above 35kts on the south side of the storm. Not much of an reduction needed to get surface winds as the plane is flying so low at nearly 1000mb. I have seen the NHC designate for far less (cough cough Andrea and Barry). Likely will go straight to Chantal at 5 in the likely event recon finds higher winds closer to the center and on the eastern parts of the storm where convection is stronger.

[tropicwatch]

Peak Flight-Level Winds: 33kt at 18:24z

Time: 18:28:30Z
Coordinates: 29.717N 78.400W
Acft. Static Air Press: 995.0 mb
Acft. Geopotential Hgt: 162 m (531 ft)
Extrap. Sfc. Press: 1013.8 mb (29.94 inHg)
Flt. Lvl. Wind (30s): From 206° at 32 kts (From the SSW at 36.8 mph)
Air Temp: 23.5°C (74.3°F)
Dew Pt: 23.1°C (73.6°F)
Peak (10s) Flt. Lvl. Wind: 34 kts (39.1 mph)
SFMR Peak (10s) Sfc. Wind: 38 kts (43.7 mph)
SFMR Rain Rate: 0 mm/hr

[sasha_B]

ATCF Best Track (per noaa.gov) now says that this is a subtropical depression:

AL, 92, 2025070418, , BEST, 0, 309N, 790W, 30, 1012, SD, 34, NEQ, 0, 0, 0, 0, 1014, 120, 85, 40, 0, L, 0, , 0, 0, INVEST, S, 0, , 0, 0, 0, 0, genesis-num, 006,

...though the navy.mil sector file still lists it as 92L rather than 03L, and I'm not sure which is more current.

[LarryWx]

The winds are high enough but is the circulation yet tight enough to be classified as a TD+? Based on images with wind barbs, it seems kind of broad so far. Regardless, I’d think this will make TD+ status if not immediately.
Opinions?

[wxman57]

SFMR measures 10 second wind, not 1-min. However, it's as well defined as Barry ever was...

[OuterBanker]

Right weighted sheared mess typical for this time of year. The developing cdo over the center is interesting. Large expanding llc (visible even here on the northern OBX). But, I think there is too much sw shear to allow too much development. Unfortunately the OBX will be on the east side which will mean more rain. Good agreement with models making landfall somewhere between Charleston and Myrtle. Only caveat is if it meanders a bit longer over the Gulf stream, shear relaxes a bit, and it separates more from the trough. I do remember a few years ago when a td formed just of the coast and went from a td to cat 2 in 36 hrs. If it splits from the trough all bets are off.
As we all know split happens.

[cycloneye]

 https://x.com/TylerJStanfield/status/1941218986190049570

[floridasun]

likely be strong td to weak ts before move out to sea

[ronjon]

Looking at the VIS SAT - is the LLC decoupled from the MLC? LLC being further west than MLC. Westerly shear keeping the system in check for now. Definitely can see subtropical storm Chantal in the future.

[sasha_B]

likely be strong td to weak ts before move out to sea

The official forecast will be available within an hour so I may be off base here, but as far as I know most models now show AL03 moving onshore somewhere along the Carolina coastline rather than out to sea, and the NHC's last tropical weather outlook mentioned a "generally north-northwestward" motion.

[underthwx]

Oh yeah, she’s on her way for sure.

This is my first post of the season. Good to be back. Happy 4th everyone!

She came to be quickly!!

First post for me in 2025 too. Everyone have a great 4th!

Hapoy 4th Buck. And everyone!

[cycloneye]

NHC will initiate advisories on Tropical Depression Three, located in the Atlantic Ocean offshore of the southeastern United States, at 500 PM EDT (2100 UTC).