ATL: HELENE - Post-Tropical - Discussion

[Nederlander]

When was the last Microwave scan? How big of a core are we talking here?

Core stretches nearly the whole width of the Yucatán channel. ~100 miles

[Travorum]

When was the last Microwave scan? How big of a core are we talking here?

Here's the latest, about 3.5 hours old:

[aspen]

When was the last Microwave scan? How big of a core are we talking here?

https://tropic.ssec.wisc.edu/real-time/mimtc/2024_09L/web/gifsBy12hr_02.gif

Core stretches nearly the whole width of the Yucatán channel. ~100 miles

Look at how the band on the eastern side fades towards the end. I think we’re going to see the thicker band on the west side curl around and pinch of a smaller, more typical-sized eyewall as convection continues to rotate around. Just my 2 cents.

[WaveBreaking]

ATCF Best Track now @ 60kts, 979 mbar

AL, 09, 2024092512, , BEST, 0, 211N, 862W, 60, 979, TS, 50, NEQ, 60, 60, 0, 40, 1008,

EDIT: nvm this was updated an hour ago

[Charleswachal]

May or may not be a technical landfall, but Helene's core is certainly causing impacts on the northeast coast of the Yucatan including Cancun. Any observations from there?

Based on radar and recon there is no direct landfall. Brian McNoldy at University of Miami has some amazing radar loops for current and past systems:
https://bmcnoldy.earth.miami.edu/tropics/radar/

https://bmcnoldy.earth.miami.edu/tropics/helene24/Helene_24-25Sep24_lbj.gif

Latest recon mission:
https://i.imgur.com/NMTEOth.png

https://tropicalatlantic.com/recon/recon.cgi?basin=al&mapping=cesium

The NE coastline of the Yucatan peninsula is definitely feeling the effects. Rotating hot towers have been forming around the core and being dragged onshore:
https://i.imgur.com/l5mn66O.gif

absolutely amazing satellite image here!

[Travorum]

When was the last Microwave scan? How big of a core are we talking here?

https://tropic.ssec.wisc.edu/real-time/mimtc/2024_09L/web/gifsBy12hr_02.gif

Core stretches nearly the whole width of the Yucatán channel. ~100 miles

Look at how the band on the eastern side fades towards the end. I think we’re going to see the thicker band on the west side curl around and pinch of a smaller, more typical-sized eyewall as convection continues to rotate around. Just my 2 cents.

Looking at the mid level features I would agree. I think the most likely scenario is that the band just offshore of Cozumel wraps up on the east side at around 86W to form an eyewall.

[otowntiger]

When was the last Microwave scan? How big of a core are we talking here?

https://tropic.ssec.wisc.edu/real-time/mimtc/2024_09L/web/gifsBy12hr_02.gif

Core stretches nearly the whole width of the Yucatán channel. ~100 miles

Looks to me as if interaction with the tip of the Yucatán disrupted the development of the eye wall somewhat, according to that loop. That could be somewhat helpful in slowing/delaying the RI process.

[USTropics]

That was a pretty significant pulse up phase, Helene is well on its way towards establishing an inner core now. From radar and recon data it does look like there might be some faint mid-level dry air entrainment that it's still working through. Latest recon pass is holding pressure steady at about 979mb:

[REDHurricane]

That was a pretty significant pulse up phase, Helene is well on its way towards establishing an inner core now. From radar and recon data it does look like there might be some faint mid-level dry air entrainment that it's still working through. Latest recon pass is holding pressure steady at about 979mb:
https://i.imgur.com/d16BF18.png

For reference, this morning's HAFS-B run that looks like this right before landfall doesn't show Helene getting down to 979mb until 7-8 hours from now:

[Powellrm]

That core is looking ominous!

[url]https://www.tropicaltidbits.com/sat/satlooper.php?region=09L&product=ir/url]

Wow that is an impressive storm. Pulling itself together very quickly.

[psyclone]

This storm reminds me of Katrina when it emerged into the Gulf and was doing that wsw move north of western Cuba. Absolutely enormous and everyone knew they were watching something exceptional

[Canelaw99]

Does anyone know if Palm Beach District schools will be closed tomorrow, 9/26/24?

I work in Miami-Dade County Schools and we haven’t heard yet. Not sure about Palm Beach. I’m sure those decisions will be made today.

[Poonwalker]

It’s crazy how on visible it looked destined to plow into the western tip of Yucatan and radar shows a completely different northward motion.

[WaveBreaking]

[Charleswachal]

It’s crazy how on visible it looked destined to plow into the western tip of Yucatan and radar shows a completely different northward motion.

I am wondering if she is still tilted or something because you are right one looks to be heading westward (sat) and radar shows it moving northward through the channel

[technikal]

When was the last Microwave scan? How big of a core are we talking here?

https://tropic.ssec.wisc.edu/real-time/mimtc/2024_09L/web/gifsBy12hr_02.gif

Core stretches nearly the whole width of the Yucatán channel. ~100 miles

Looks to me as if interaction with the tip of the Yucatán disrupted the development of the eye wall somewhat, according to that loop. That could be somewhat helpful in slowing/delaying the RI process.

Agreed, that sudden westerly wobble in the YP seems like it will abate eyeball formation, at least for a little.

[chris_fit]

It’s crazy how on visible it looked destined to plow into the western tip of Yucatan and radar shows a completely different northward motion.

I am wondering if she is still tilted or something because you are right one looks to be heading westward (sat) and radar shows it moving northward through the channel

And recon fixes are showing an Eastward component

[ColdMiser123]

68 kt flight level wind - supports 61 kt at the surface. Right on the cusp of hurricane intensity now.

[WaveBreaking]

[eastcoastFL]

Does anyone know if Palm Beach District schools will be closed tomorrow, 9/26/24?

I work in Miami-Dade County Schools and we haven’t heard yet. Not sure about Palm Beach. I’m sure those decisions will be made today.

I just got a text that after school programs are cancelled today and tomorrow and they'll decide on school closures this afternoon.