ATL: ETA - Post-Tropical - Discussion

[Shell Mound]

Had to post this loop so it would be saved somewhere in the archives. I can't remember having seen this much pink before for a system that wasn't even designated as a TD or PTC yet.

https://imgur.com/jzOEtpJ

Shear clearly appears to be lessening, based on the “feathery” outflow concomitant with expansion and diffusion of the temperature gradient. The vector of the shear also appears to be changing from westerly to southerly, or at least seems to be backing. Given these trends, I think a depression or even a marginal storm could form overnight. This would clearly favour the HWRF and certain GFS ensemble members that show more organisation in the short term. This trend would also favour a slower, deeper system that curves earlier and does not track well inland from coastal Central America, given that the EC members both a) take 96L well inland over Central America and b) are generally weaker with 96L in the short term vs. the HWRF and some of the GFS ensemble members.

[Keldeo1997]

No ASCAT but microwave got it and there seems to be some banding?

[Shell Mound]

https://cdn.discordapp.com/attachments/716215692617187328/772005481358426112/20201031.png

No ASCAT but microwave got it and there seems to be some banding?

The convective pattern resembles that of a southeastward-moving supercell. That migratory-“supercell” appearance is often a hallmark of potential ERI.

[Keldeo1997]

https://cdn.discordapp.com/attachments/716215692617187328/772005481358426112/20201031.png

No ASCAT but microwave got it and there seems to be some banding?

The convective pattern resembles that of a southeastward-moving supercell. That migratory-“supercell” appearance is often a hallmark of potential ERI.

Another pass and its even better

[northjaxpro]

Had to post this loop so it would be saved somewhere in the archives. I can't remember having seen this much pink before for a system that wasn't even designated as a TD or PTC yet.

https://imgur.com/jzOEtpJ

Yeah, my biggest fear may be realized soon with.this quickly developing cyclone . This system has all the makings to become one of the most intense tropical cyclones EVER in the Caribbean. The upper level environment now going forward is about as perfect as you can have it with very minimal shear and a robust anticyclone over it. Plus, on top of that, very excellent OHÇ and warm ssts for future Eta to really feed and grow. I have no doubt that we are well looking at a strong potential of yet another major tropical cyclone in the coming days, a potential Cat 4 or even a 5 is definitely.on the table.

I said back on Thursday that it would be foolish to not keep ALL options on the table with this cyclone. You are talking about a very late season storm in the Caribbean, which are at times a very tricky and difficult proposition to forecast. Caribbean cyclones this time.of the year can be very complex and challenging to forecast. This cyclone will not be any different!

ALL interests across the Caribbean need to stay vigilant! Yes, the Eastern GOM and everyone of us in Florida needs to closely monitor the progress of this developing cyclone. The insanity of 2020 just keeps on going like the EverReady Energizer Bunny. It just keeps on going and going unfortunately. This season will go down as THE MOTHER of all of them when it will finally be over and done, God we hope it will be eventually!

[GCANE]

IR Satellite Analysis showing a typical TD wind-field signature

[GCANE]

[GCANE]

Anticyclone right on top of the CoC.
Can't get much better than that.

[Owasso]

[northjaxpro]

https://cdn.discordapp.com/attachments/716215692617187328/772005481358426112/20201031.png

No ASCAT but microwave got it and there seems to be some banding?

I think that microwave pass clearly shows banding rotating into the LLC. We probably have a TD or even a TS, looking at the intense convection already firing around the center in all likelihood imo. I think we will see this named ery soon, especially if this begins to really ramp up, like I am unfortunately anticipating to happen in the very near term.

[GCANE]

As long as those 2 ULLs don't get too close, outflow will be improving dramatically.

[GCANE]

Tower moving over the CoC in an unusual trajectory.

[GCANE]

TC level rain rate.
Conversion from a wave to a TC well under way as indicated by the wave's peripheral convective band turning into a feeder band.
Also a secondary feeder band is also trying to form directly from the south.

[northjaxpro]

GCANE, this thing left the stables awhile ago. This system is well off to the races.

[GCANE]

:uarrow: GCANE, this thing left the stables awhile ago. This system is well off to the races.

Comparing IR wind field and GFS initial conditions; as usual, GFS is way off.
At UL, GFS doesn't even come close to showing an anticyclone.
Obviously a big need for recon data.
Once that gets into the models, which won't be for a good 24 hrs, I think there will be a large shock factor.

[xironman]

Nice and symmetrical for so early in development

[cycloneye]

90%/90%

A vigorous tropical wave located over the central Caribbean Sea
continues to produce a concentrated area of thunderstorms. This
system is gradually becoming better organized, and conditions are
conducive for further development. A tropical depression is expected
to form during the next day or so while the disturbance moves
generally westward into the western Caribbean Sea. Interests in
Honduras and Nicaragua should monitor the progress of this system.
Regardless of development, this disturbance is expected to produce
heavy rainfall across portions of the ABC Islands and Jamaica
through the weekend.
* Formation chance through 48 hours...high...90 percent.
* Formation chance through 5 days...high...90 percent.

[GeneratorPower]

Had to post this loop so it would be saved somewhere in the archives. I can't remember having seen this much pink before for a system that wasn't even designated as a TD or PTC yet.

https://imgur.com/jzOEtpJ

Yeah, my biggest fear may be realized soon with.this quickly developing cyclone . This system has all the makings to become one of the most intense tropical cyclones EVER in the Caribbean. The upper level environment now going forward is about as perfect as you can have it with very minimal shear and a robust anticyclone over it. Plus, on top of that, very excellent OHÇ and warm ssts for future Eta to really feed and grow. I have no doubt that we are well looking at a strong potential of yet another major tropical cyclone in the coming days, a potential Cat 4 or even a 5 is definitely.on the table.

I said back on Thursday that it would be foolish to not keep ALL options on the table with this cyclone. You are talking about a very late season storm in the Caribbean, which are at times a very tricky and difficult proposition to forecast. Caribbean cyclones this time.of the year can be very complex and challenging to forecast. This cyclone will not be any different!

ALL interests across the Caribbean need to stay vigilant! Yes, the Eastern GOM and everyone of us in Florida needs to closely monitor the progress of this developing cyclone. The insanity of 2020 just keeps on going like the EverReady Energizer Bunny. It just keeps on going and going unfortunately. This season will go down as THE MOTHER of all of them when it will finally be over and done, God we hope it will be eventually!

northjaxpro lays it down and starts taking names. Models thread looking and smelling like a locker room. GFS dishing up post-election doom for FL. Interesting times.

[Weatherboy1]

Well this certainly escalated quickly! Satellite presentation this morning vs yesterday evening is like night and day (or day and night I guess!) Also keeping an eye on the U.S. models, which have shifted big time from the “bury it in CA” story to a more Wilma-esque track. Still early and plenty of time to watch. But going to be an interesting start to November for sure.

[cycloneye]

Looking good on recent microwave.