ATL: EPSILON - Post-Tropical

[cycloneye]

8 AM:

Showers and thunderstorms associated with a non-tropical low
pressure system located about 550 miles east-southeast of Bermuda
have been gradually increasing in both coverage and organization
during the past 24 hours. Further development is expected, and a
subtropical depression or storm is very likely to form during the
next day or so while the low meanders well to the southeast of
Bermuda.
* Formation chance through 48 hours...high...80 percent.
* Formation chance through 5 days...high...90 percent.

[JRD]

Invest 94L right now has a barely (almost on the thin white border between warm and cold) warm core, which is also shallow and near the border between symmetric and asymmetric (though appreciably symmetric). It resembles a subtropical cyclone in convection organization, satellite appearance, and the shallow warm core.

How can I tell if a system is warm or cold core or borderline?

It's a phase diagram. It can be classified as warm-cored if it falls within even the lightest shade of pink or magenta. It's cold-cored if it falls within even the lightest shade of blue or grey. Borderline may not be an useful concept, given that the white lines that separates the wam core and cold core quadrants may actually form part of these quadrants. They can also be classified as warm or cold cored depending on the thermal nature of their center in the lower troposphere, and can be subdivided into shallow or deep (plus moderate for warm cores) depending on the thermal nature of their center in the mid and upper troposphere.

[aspen]

This thing is taking forever to concentrate. I thought we would’ve had a TC by now. Meanwhile, everyone is arguing over the Caribbean disturbance and how it’s vanished from half of the models.

The tropics are really testing our collective patience right now.

[NXStumpy_Robothing]

This thing is taking forever to concentrate. I thought we would’ve had a TC by now. Meanwhile, everyone is arguing over the Caribbean disturbance and how it’s vanished from half of the models.

The tropics are really testing our collective patience right now.

Reminds me of everyone getting really impatient with pre-Isaias.

[ElectricStorm]

IR presentation looks awful compared to the last few days... Zero convection on the west side of the center, everything is well removed from the center to the east. It looked close to a TC or STC the last few days, but not anymore... Keep in mind that the model runs that had this storm stronger have had the Caribbean system weaker, so if this trend keeps up, I can see the NHC lowering percentages, while the potential Caribbean storm could become a bit more concerning even though many posters are already cancelling it after one day of model runs... IMO

[cycloneye]

Showers and thunderstorm activity associated with a non-tropical
low pressure system located about 600 miles southeast of Bermuda is
poorly organized and displaced well east of the low-level center.
Environmental conditions remain conducive for development, and a
subtropical depression or storm is very likely to form during the
next day or so while the low meanders well to the southeast of
Bermuda.
* Formation chance through 48 hours...high...80 percent.
* Formation chance through 5 days...high...90 percent.

[Iceresistance]

The system has become less organized according to the NHC, but the convective activity has increased on the eastern side of the system.

(Have you noticed something SW of Cape Verde? It looks like there is something trying to organize, but it has a very low chance of organizing & wind shear is higher there.)

[Ubuntwo]

Verging on classifiable with a center mostly covered by convection.

[Jr0d]

It's getting there. I was expecting the convection to persist overnight yesterday. Let's see if it can make 12 hours+ with convection near the center.

[cycloneye]

8 PM:

Showers and thunderstorms associated with a large non-tropical low
pressure system located about 700 miles southeast of Bermuda remain
poorly organized and displaced mainly to the east of the low-level
center. Environmental conditions are forecast to be only marginally
conducive for development during the next day or two. Although a
subtropical or tropical depression could still develop during that
time, upper-level winds are expected to become more favorable for
tropical cyclone formation to occur by late Tuesday and Wednesday
while the low meanders well to the southeast of Bermuda.
* Formation chance through 48 hours...high...80 percent.
* Formation chance through 5 days...high...90 percent.

[Iceresistance]

Look like that the convection is now at the east side of the circulation.

[cycloneye]

No upgrade at 11 PM but convection is growing near the low so maybe at 5 AM we may have a STD or TD if convection can cover the low.

[ElectricStorm]

No upgrade at 11 PM but convection is growing near the low so maybe at 5 AM we may have a STD or TD if convection can cover the low.

https://i.imgur.com/U2OyWN6.gif

Yeah that looks much better than earlier today... should be ready to go pretty soon

[CyclonicFury]

Looks like Epsilon is about to make its return. I wonder if this one will be as tenacious as its 2005 version, which seemingly annoyed the NHC.

[Ubuntwo]

hmm

[us89]

Looks like a sheared subtropical depression to me. If we don’t see this classified at 5, I’m betting it happens by 11.

[StrongWind]

Invest 94L right now has a barely (almost on the thin white border between warm and cold) warm core, which is also shallow and near the border between symmetric and asymmetric (though appreciably symmetric). It resembles a subtropical cyclone in convection organization, satellite appearance, and the shallow warm core.

How can I tell if a system is warm or cold core or borderline?

It's a phase diagram. It can be classified as warm-cored if it falls within even the lightest shade of pink or magenta. It's cold-cored if it falls within even the lightest shade of blue or grey. Borderline may not be an useful concept, given that the white lines that separates the wam core and cold core quadrants may actually form part of these quadrants. They can also be classified as warm or cold cored depending on the thermal nature of their center in the lower troposphere, and can be subdivided into shallow or deep (plus moderate for warm cores) depending on the thermal nature of their center in the mid and upper troposphere.

Is this the one you are looking at? - http://moe.met.fsu.edu/cyclonephase/ams ... 900/1.html

That sucker is hard to find. Took me a couple of minutes.

[Ubuntwo]

How can I tell if a system is warm or cold core or borderline?

It's a phase diagram. It can be classified as warm-cored if it falls within even the lightest shade of pink or magenta. It's cold-cored if it falls within even the lightest shade of blue or grey. Borderline may not be an useful concept, given that the white lines that separates the wam core and cold core quadrants may actually form part of these quadrants. They can also be classified as warm or cold cored depending on the thermal nature of their center in the lower troposphere, and can be subdivided into shallow or deep (plus moderate for warm cores) depending on the thermal nature of their center in the mid and upper troposphere.

Is this the one you are looking at? - http://moe.met.fsu.edu/cyclonephase/ams ... 900/1.html

That sucker is hard to find. Took me a couple of minutes.

No, this would be 94L ↓

[Iceresistance]

Convection is at the center, NHC gives the system 90-90%

[Iceresistance]

Looks like a sheared subtropical depression to me. If we don’t see this classified at 5, I’m betting it happens by 11.

Still 94L, but they are saying that the system is now at 90-90% Chance