Unusually organized cyclone in the SE Atlantic

[TheAustinMan]

Over the past two days, an upper-level trough dipped equatorward (northward) over the Southeastern Atlantic off the coast of South Africa. A more tightly-wound circulation developed within this broader system, and has looked intriguing on visible satellite (it remains a very shallow system, with cloud tops generally no cooler than -40C). An ASCAT pass this morning discerned winds of about 35+ kt.

Global model initializations suggest a central pressure in the low 1000s mbar, and models generally indicate the vortex will continue moving back south and eventually lose its identity tomorrow. While cyclone phase diagrams are in strong consensus that this is a fully extratropical cold-core system, it wouldn't surprise me given the convective characteristics if there had been some warm-seclusion evolution.

Source: SSEC RealEarth


Source: EOSDIS WorldView

[Hurricaneman]

Looks to be at least subtropical if not a hurricane

[JetFuel_SE]

I Believe this would be only the 2nd ever (sub)tropical system in the eastern half of the South Atlantic.

[Hurricane2022]

Bye, Mr. Unnamed.
 https://twitter.com/KacperWx/status/1771910640208167201

[doomhaMwx]

VIIRS pass at 12:36Z

[doomhaMwx]

Impressive low-level eyewall on this AMSR-2 microwave image (36.5 GHz), taken around the same time as the VIIRS pass above. This was likely the peak of the system.



Compare that to the image below taken just ~12 hours earlier — notable development in a short amount of time.

[JetFuel_SE]

I Believe this would be only the 2nd ever (sub)tropical system in the eastern half of the South Atlantic.

Chalane's remnants actually reached the South Atlantic, and honestly didn't look too bad at the time.

[Sciencerocks]

Looked like a hurricane to me. 65 knts. Just as much so as the hurricane last january.