ATL: ZETA - Post-Tropical - Discussion

[Nimbus]

Is it just me or does it appear that the LLC is moving out at the NW edge of convection once again? Looks like the MLC is hanging back while the LLC started moving NW.

That is what recon is finding but its much better stacked than it was yesterday and intensifying.
Tracking towards Cozumel but if it starts turning north they may need to extend warnings east to Destin Fl.
Watching the trough evolution near west Texas and remembering hurricane Charley.
If Zeta is just south of NOLA headed ENE instead of NE landfall is harder to predict.

[aspen]

Zeta was right in the intensity range I predicted last night. The LLC is still displaced and isn’t right under the <-80C CDO, but when it finally is, it’ll likely be on its way to a Cat 2/3.

[kevin]

Considering the time left until landfall in Yucatan I don't think a cat 4/5 like Delta is possible (might be possible for that tropical wave that has a lot of model support for the 1st week of November), but if it starts intensifying soon I think a cat 2/3 is definitely on the table.

[GCANE]

Here's the setup in the GoM.
Rossby Wave created by a strong ULL over AZ.
Zeta will be entering the GoM in its associated ARWB.
Any track east of forecast and Zeta will be more under the anticyclone which will allow for higher than expected strengthening.
CAPE is forecast to be high in the east GoM due to the Loop Current and pull-in from the W Carib.
This could be very nasty if it tracks more to AL, FL Panhandle especially if it can maintain a deep cold pool.

GFS is trending the Rossby Wave to move east slower which allows the ridge off the GA coast to push back Zeta for a later landfall.
If Zeta makes landfall closer to the Yucatan Channel then it will have more time in the GoM to intensify.

Final CONUS landfall target is yet to be determined.
UL forecast from GFS appears to be very erroneous with it currently showing the anticyclone well west of its current position.

[Iceresistance]

Anticyclone positioned along the north Belize coast causing some UL NW winds over the CoC.
However, outflow on the NW quad appears to be improving indicating the anticyclone maybe weakening or moving closer to the CoC.

It's trying to connect with the Zeta. & it's giving Zeta low wind shear.

[Iceresistance]

Here's the setup in the GoM.
Rossby Wave created by a strong ULL over AZ.
Zeta will be entering the GoM in its associated ARWB.
Any track east of forecast and Zeta will be more under the anticyclone which will allow for higher than expected strengthening.
CAPE is forecast to be high in the east GoM due to the Loop Current and pull-in from the W Carib.
This could be very nasty if it tracks more to AL, FL Panhandle especially if it can maintain a deep cold pool.

GFS is trending the Rossby Wave to move east slower which allows the ridge off the GA coast to push back Zeta for a later landfall.
If Zeta makes landfall closer to the Yucatan Channel then it will have more time in the GoM to intensify.

Final CONUS landfall target is yet to be determined.
UL forecast from GFS appears to be very erroneous with it currently showing the anticyclone well west of its current position.


https://i.imgur.com/1PAjM6W.png


https://i.imgur.com/iPV87JW.png

The Anticyclone's center position is over Belize, & Zeta is not far away from it.

[Aric Dunn]

Per soundings and the upper G-IV recon flight this morning some ridging has begun to build in. Now we have to see how much Zeta responds. Does it drift to the NW or take like a rocket per the Euro. The slower it moves the more right shifts we will see.

[underthwx]

Per soundings and the upper G-IV recon flight this morning some ridging has begun to build in. Now we have to see how much Zeta responds. Does it drift to the NW or take like a rocket per the Euro. The slower it moves the more right shifts we will see.

So, would a faster moving Zeta, help keep the intensity down?...

[Aric Dunn]

Per soundings and the upper G-IV recon flight this morning some ridging has begun to build in. Now we have to see how much Zeta responds. Does it drift to the NW or take like a rocket per the Euro. The slower it moves the more right shifts we will see.

So, would a faster moving Zeta, help keep the intensity down?...

No, it will still have plenty of time over warm water.

[3090]

Per soundings and the upper G-IV recon flight this morning some ridging has begun to build in. Now we have to see how much Zeta responds. Does it drift to the NW or take like a rocket per the Euro. The slower it moves the more right shifts we will see.

Have not seen any right shifts per se. So far things have trended west. The Euro has been far to the west, while the GFS has been far to the east. They both are slowly, but surely migrating towards one another. Once that occurs, the window for the landfall, is with increasing confidence, inside of 60 hours, which we are now within.

We should see a jet like move begin today by Zeta, with a continued faster forward speed all the way thru landfall. I do not think this one, will have any surprises as far as track. It looks pretty clear with the forecast of the weather pattern evolving. Could there be a small shift west/east, of current landfall forecast? Certainly. 100-200 miles west/east? Not a chance IMO.

[Frank2]

The GFS data consistently indicating a fairly weak system as it approaches the Gulf Coast - shear might play a bigger role IMO and overall the environment in the Gulf not favoring any strengthening.

This reminds me of Spring snows and how the increasing sun angle prevents snow from sticking on pavement - it's not so much the weather pattern but the time of year and the same is true in the Gulf, when a weather event just cannot happen because the time for it to happen fully has passed due to seasonal change...

[Iceresistance]

It really looks like a hurricane right now.

[kevin]

It really looks like a hurricane right now.

https://www.nrlmry.navy.mil/tcdat/tc20/ATL/28L.ZETA/ir/geo/1km_bw/LATEST.jpg

When is recon supposed to enter the storm again? Indeed looks very hurricane-like atm, at least better than Nana when it was a minimal cat 1.

[aspen]

I’m doubting this is going to become a major now. A hurricane is guaranteed (it’s already at 60 kt and the last recon mission found 65+ kt FL winds), but its structural evolution has been way too slow for RI into a Cat 3/4. Part of the circulation is STILL exposed with only 12-15 hours to go until landfall, which means there isn’t enough time for a solid eyewall to form and RI to begin before it runs out of water. Probably won’t be stronger than Delta at landfall in Mexico.

[NDG]

Put me down also in doubting Zeta will become a hurricane this morning, maybe later today as it makes landfall.
BTW, 06z Euro now shows Zeta as a Cat 2 making landfall in SE LA.

[aspen]

Put me down also in doubting Zeta will become a hurricane this morning, maybe later today as it makes landfall.

https://i.imgur.com/SltaOlP.jpg

Quite a contrast between the fantastic looking UL environment, and the bit of shear that keeps this from having a core. We might be looking at another “if it had more time over water” storm that won’t be too bad for TC-weary Cancún (seriously this is their third landfall in barely a month, 2020 seems to hate them almost as much as it hates Louisiana).

[xironman]

Does seem like it can stack, weird, the environment looks good.

[ElectricStorm]

Yeah this thing isn't getting anywhere close to a major now. 65-75 kts before landfall now IMO

[Ken711]

NHC now has a US landfall at 2:00 AM Thursday, has it slowed that much?

[Dean4Storms]

NHC now has a US landfall at 2:00 AM Thursday, has it slowed that much?

No they don't. That 2am position on Thurs is in SW AL. Landfall on the SE LA Coast is Wednesday evening.