ATL: ZETA - Post-Tropical - Discussion

[Airboy]

A. Time of Center Fix: 25th day of the month at 7:31:39Z
B. Center Fix Coordinates: 17.70N 83.44W

How does that compare to the previous center location?...

Have not follow the storm that close, but last advisary put it at around 18.5 N so it a good bit south of that. And I think it previous was around 18.9 N?
?

[chaser1]

Just woke up for a peek lol. Not only is a center relocation occurring south of NHC's earlier position but I'd also say further east as well. I'm curious just how close T.S. force winds are actually occurring from NHC center depiction?

[northjaxpro]

I would not put much stock in the previous model runs with such a significant relocation of the center.

This is a very complex situation right now with this meandering Zeta cyclone

[underthwx]

A. Time of Center Fix: 25th day of the month at 7:31:39Z
B. Center Fix Coordinates: 17.70N 83.44W

How does that compare to the previous center location?...

Have not follow the storm that close, but last advisary put it at around 18.5 N so it a good bit south of that. And I think it previous was around 18.9 N?
?

Sounds about right....thanks for posting the new center location....it seems as if the center has reformed?, as mentioned in the 11 pm NHC discussion....

[underthwx]

I would not put much stock in the previous model runs with such a significant relocation of the center.

This is a very complex situation right now with this meandering Zeta cyclone

You got that right Jax....complex indeed!....I will spare you the hundred questions I want to ask...so many variables and unknowns at this time...I assume the models will reflect this center reformation, and show an Eastward shift in the track perhaps?....I haven't looked at a map to compare the new center location, with the previous one, so please bear with me...lol

[northjaxpro]

I would not put much stock in the previous model runs with such a significant relocation of the center.

This is a very complex situation right now with this meandering Zeta cyclone

You got that right Jax....complex indeed!....I will spare you the hundred questions I want to ask...so many variables and unknowns at this time...I assume the models will reflect this center reformation, and show an Eastward shift?...

Well, we will get a better picture later today with the 12Z runs. The Recon data from right now will be imputed for that cycle later today. I am expecting eastward shifts underthwx.

[underthwx]

I would not put much stock in the previous model runs with such a significant relocation of the center.

This is a very complex situation right now with this meandering Zeta cyclone

You got that right Jax....complex indeed!....I will spare you the hundred questions I want to ask...so many variables and unknowns at this time...I assume the models will reflect this center reformation, and show an Eastward shift?...

Well, we will get a better picture later today with the 12Z runs. The Recon data from right now will be imputed for that cycle later today. I am expecting eastward shifts underthwx.

Thanks for the info....that will be very interesting to be sure!...

[JamesRainier]

A. Time of Center Fix: 25th day of the month at 7:31:39Z
B. Center Fix Coordinates: 17.70N 83.44W

How does that compare to the previous center location?...

TROPICAL DEPRESSION CENTER LOCATED NEAR 18.9N 83.1W AT 25/0300Z
POSITION ACCURATE WITHIN 40 NM

AT 25/0000Z CENTER WAS LOCATED NEAR 18.9N 83.1W

https://www.nhc.noaa.gov/archive/2020/a ... .002.shtml?

Degrees of latitude are 60 NM apart.

[xironman]

I would not put much stock in the previous model runs with such a significant relocation of the center.

This is a very complex situation right now with this meandering Zeta cyclone

You got that right Jax....complex indeed!....I will spare you the hundred questions I want to ask...so many variables and unknowns at this time...I assume the models will reflect this center reformation, and show an Eastward shift?...

Well, we will get a better picture later today with the 12Z runs. The Recon data from right now will be imputed for that cycle later today. I am expecting eastward shifts underthwx.

Big east shift in the 06z GFS, looks like because it came in stronger.

[cp79]

I know I keep bringing up Mitch, but this is starting to look eerily similar. It could crash into Honduras soon.

[Nimbus]

I know I keep bringing up Mitch, but this is starting to look eerily similar. It could crash into Honduras soon.

I think the center is further north than the mid level blob and meandering a little east, should be visible.
Bone dry air just to the NW and in the gulf as the first digging trough comes through.
00z HWRF still showing drier air in western gulf as moisture envelope moving with Zeta may be limited.
A difficult trough forecast near landfall is required but in general a further east landfall would mean a stronger storm(for similar hourly run evolutions).
Models aren't calling for much increase in strength for another 12 hours till Zeta can stack.

The chances of Zeta diving into the Honduras are about as high as a 43 degree bearing into Tampa bay, not even in the cone.

[Blown Away]

A. Time of Center Fix: 25th day of the month at 7:31:39Z
B. Center Fix Coordinates: 17.70N 83.44W

Significant south relocation of the center.

Ok, if we are going with 17.7N/83.4W and the relocation is closer to the convection. That center fix is almost void of convection again, so either the structure is poor or that center will continue to drop farther S and follow the S moving deep convection ball.

[northjaxpro]

A. Time of Center Fix: 25th day of the month at 7:31:39Z
B. Center Fix Coordinates: 17.70N 83.44W

Significant south relocation of the center.

Ok, if we are going with 17.7N/83.4W and the relocation is closer to the convection. That center fix is almost void of convection again, so either the structure is poor or that center will continue to drop farther S and follow the S moving deep convection ball.

The structure is not symmetric currently, and it is trying to stack vertically. I think Zeta eventually will structually improve later today with the LLC and MLC aligning itself.

[gatorcane]

Wow what a good discussion by Stewart. Lots of details as to the forecast reasoning.

Really interesting snippet:

Phasing of northern
and southern stream systems is always difficult to forecast,
especially when one of those systems is outside the U.S. upper-air
observing system like the system currently is off southern
California.

[Blown Away]

Snipet from 5am Disco: The initial motion estimate is stationary. Although Zeta has been
steadily losing latitude during the past 12 hours, this has been
primarily due to the broad low-level center reforming closer to the very intense convection located in the southern semicircle of the cyclone's large circulation. Satellite trends over the past 6 hours indicate that a mid-level circulation located about 90 nmi east of the low-level center is likely imparting a weak southerly component of motion on Zeta as well.

IMO, watching the deep convection the S movement is continuing with a slight E component...

[Weatherboy1]

You got that right Jax....complex indeed!....I will spare you the hundred questions I want to ask...so many variables and unknowns at this time...I assume the models will reflect this center reformation, and show an Eastward shift?...

Well, we will get a better picture later today with the 12Z runs. The Recon data from right now will be imputed for that cycle later today. I am expecting eastward shifts underthwx.

Big east shift in the 06z GFS, looks like because it came in stronger.

Like I said in the model thread and here yesterday afternoon, I see very little chance this landfalls west of around Panama City beach. You HAVE to give models a “climatology adjustment” (informally) this time of year. Much more likely they will adjust East with time and this thing will never landfall in any state whose name starts with any letter other than “F”

[NDG]

During this season every time a storm has reformed further south it has resulted in the storm going further west than previously forecasted. South central LA to Mobile are in highest probability of Zeta making landfall, IMO. It will be moving NNE to NE as it gets pulled by the trough so affected areas will be wide to the east.

[Jr0d]

During this season every time a storm has reformed further south it has resulted in the storm going further west than previously forecasted. South central LA to Mobile are in highest probability of Zeta making landfall, IMO. It will be moving NNE to NE as it gets pulled by the trough so affected areas will be wide to the east.

This is a different setup.

With Zeta being further south initially, it will most certainly further south when the trough scoops it up and 'ejects' it NE, so it will likely end up well east of yesterday's model consensus.

There is still a small chance it misses the trough. If that happens all bets are off.

[xironman]

Nice tower setting off right about at the last center fix. HWRF and HMON both call for strengthening today. As mentioned above an interesting forecast because of the phase of the northern and southern jets. The 500mb low over Texas will be pretty impressive. I wonder if it ends up enhancing Zeta in the end.

[tiger_deF]

Zeta couldn't find a better place to meander if it tried. It's currently over the hottest and highest OHC waters in the Atlantic, and even if it spends days in the area I doubt significant upwelling will be a factor. The atmospheric conditions will need to be right, but if Zeta fully stacks I think a major is absolutely in the cards