SATL: Akará - Post-Tropical

[rodolfo alves]

Windy using data from Metoffice

WTNT80 EGRR 171611

MET OFFICE TROPICAL CYCLONE GUIDANCE FOR NORTH-EAST PACIFIC

AND ATLANTIC

GLOBAL MODEL DATA TIME 12UTC 17.02.2024

TROPICAL DEPRESSION 01Q ANALYSED POSITION : 24.7S 39.0W

ATCF IDENTIFIER : SA012024

VERIFYING TIME POSITION STRENGTH TENDENCY
-------------- -------- -------- --------
12UTC 17.02.2024 24.7S 39.0W WEAK
00UTC 18.02.2024 24.9S 39.1W WEAK LITTLE CHANGE
12UTC 18.02.2024 26.5S 39.6W WEAK LITTLE CHANGE
00UTC 19.02.2024 27.8S 40.8W WEAK LITTLE CHANGE
12UTC 19.02.2024 29.8S 41.3W MODERATE LITTLE CHANGE
00UTC 20.02.2024 31.1S 41.5W MODERATE LITTLE CHANGE
12UTC 20.02.2024 31.7S 40.7W MODERATE LITTLE CHANGE
00UTC 21.02.2024 31.5S 39.6W WEAK LITTLE CHANGE
12UTC 21.02.2024 32.7S 39.4W WEAK LITTLE CHANGE
00UTC 22.02.2024 33.3S 39.7W WEAK LITTLE CHANGE
12UTC 22.02.2024 BELOW TROPICAL STORM STRENGTH


THIS INFORMATION IS PROVIDED AS GUIDANCE FOR TROPICAL CYCLONE
RSMCS. IT REQUIRES INTERPRETATION BY TROPICAL CYCLONE SPECIALISTS
AND SHOULD NOT BE CONSIDERED AS A FINAL PRODUCT.

BULLETINS ARE NOW AVAILABLE WHICH PROVIDE EXPLICIT GUIDANCE
ON CENTRAL PRESSURE AND MAXIMUM WIND SPEED.
FOR FURTHER INFORMATION CONTACT TROPICAL_CYCLONES@METOFFICE.GOV.UK

MET OFFICE, EXETER, UK

[Sciencerocks]

 https://twitter.com/UWCIMSS/status/1758923275537707365

[jaguarjace]

https://www.force-13.com/satellite?flt=01Q&enh=rgb&loop=true

[rodolfo alves]

[rodolfo alves]

What will be the name when is classified as a SS Storm?

[rodolfo alves]

Chart 0Z from the Brazilian Navy maintains the system as a Subtropical Depression

[rodolfo alves]

WARNING NR 083/2024
SPECIAL WARNING
ISSUED AT 0000Z – SUN – 18/FEB/2024
SUBTROPICAL DEPRESSION WITH CENTRAL PRESSURE 1006 HPA AT 25.5S 039W, MOVING TO SOUTHWEST
WITH ESTIMATED MAXIMUM WINDS FORCE 7 (28/33 KT) ON SOUTH SECTOR AND ROUGH SEA ASSOCIATED
WITH WAVES 3.0/4.0 METERS OFFSHORE AFFECTING BRAVO AND SOUTH OCEANIC AREAS.

ESTIMATED POSITION:
180600Z: 26S 040W – 1002 HPA – MAXIMUM SUSTAINED WIND 25/30 NÓS – SUBTROPICAL DEPRESSION
181200Z: 26.5S 040.5W – 1002 HPA – MAXIMUM SUSTAINED WIND 34/40 NÓS – TROPICAL STORM
181800Z: 27.5S 041W – 1000 HPA – MAXIMUM SUSTAINED WIND 34/40 NÓS – TROPICAL STORM
190000Z: 28.5S 042W – 998 HPA – MAXIMUM SUSTAINED WIND 40/45 NÓS – TROPICAL STORM
190600Z: 29S 042.5W – 994 HPA – MAXIMUM SUSTAINED WIND 40/45 NÓS – TROPICAL STORM
191200Z: 30S 042.5W – 998 HPA – MAXIMUM SUSTAINED WIND 40/45 NÓS – TROPICAL STORM
VALID UNTIL 221200Z.

THIS WARNING REPLACES THE WARNING NR 082/2024.

[jaguarjace]

https://www.force-13.com/satellite?flt=01Q&enh=true&loop=true

[Sciencerocks]

[Subtrop]

SPECIAL WARNING

WARNING NR 086/2024
SPECIAL WARNING
ISSUED AT 1200Z – SUN – 18/FEB/2024
TROPICAL DEPRESSION WITH CENTRAL PRESSURE 1002 HPA AT 27S 040.5W, MOVING TO SOUTHWEST WITH ESTIMATED MAXIMUM WINDS FORCE ON SOUTH SECTOR AND ROUGH SEA ASSOCIATED WITH WAVES 3.0/4.0 METERS OFFSHORE AFFECTING BRAVO AND SOUTH OCEANIC AREAS.

ESTIMATED POSITION:
181800Z: 27.5S 041W – 1000 HPA – MAXIMUM SUSTAINED WIND 28/33 KT – TROPICAL DEPRESSION
190000Z: 28.5S 041.5W – 998 HPA – MAXIMUM SUSTAINED WIND 40/45 KT – TROPICAL STORM
190600Z: 29S 042.5W – 994 HPA – MAXIMUM SUSTAINED WIND 40/45 KT – TROPICAL STORM
191200Z: 29.5S 042.5W – 996 HPA – MAXIMUM SUSTAINED WIND 40/45 KT – TROPICAL STORM
191800Z: 31S 042.5W – 994 HPA – MAXIMUM SUSTAINED WIND 40/45 KT – TROPICAL STORM
200000Z: 31.5S 042.5W – 994 HPA – MAXIMUM SUSTAINED WIND 40/45 KT – TROPICAL STORM
VALID UNTIL 221200Z.

THIS WARNING REPLACES THE WARNING NR 083/2024

[Sciencerocks]

I agree with the transition to tropical as the LLC is clearly tropical in nature and the convection is much closer to the center generated by convective forcing. A good example of this is the burst that formed on the southern side in the past hour which was quickly sheared off to the south. So the problem with this system at this time is strong northerly shear won't allow it too stack. Ascat shows 30 knots but this could easily be on the otherside of the 34knt line too considering the strength of the LLC and convection south of the center...Would be awesome to have a drone or brazilian recon. lol

I suspect as it moves south the shear will become slightly less and directed in a somewhat more favorable way to allow for some convection to finally build over the center. Possibly 12-24 time frame so I also agree with their thinking of this becoming a tropical storm...Probably 45-50 knots at max.

[rodolfo alves]

[jaguarjace]

[Sciencerocks]

Based on the convection I'd say it is now a 35knot tropical storm.

[Sciencerocks]

It's kind of an irony that this is probably one of the most tropical systems of the 2020's in the south Atlantic and yet it isn't named. There's been a ton of systems clearly extratropical that got named. lol

I expect this to finally be named soon.

[Sciencerocks]

[cycloneye]

 https://twitter.com/CIMSS_Satellite/status/1759332165903323522

[rodolfo alves]

Based on the convection I'd say it is now a 35knot tropical storm.

Everything indicates that the Brazilian Navy will name the system a Tropical Storm tonight in Brazil.

[rodolfo alves]

It's kind of an irony that this is probably one of the most tropical systems of the 2020's in the south Atlantic and yet it isn't named. There's been a ton of systems clearly extratropical that got named. lol

I expect this to finally be named soon.

I agree with you.

The Brazilian Navy classifies systems mainly based on the Florida State University Cyclone phase diagram (using GFS), often ignoring the visual aspect of satellite images.

[TheAustinMan]

It's kind of an irony that this is probably one of the most tropical systems of the 2020's in the south Atlantic and yet it isn't named. There's been a ton of systems clearly extratropical that got named. lol

I expect this to finally be named soon.

I agree with you.

The Brazilian Navy classifies systems mainly based on the Florida State University Cyclone phase diagram (using GFS), often ignoring the visual aspect of satellite images.

If that's the case, then I imagine this will be named soon since the FSU GFS phase space diagram has the system in the symmetric and deep warm core quadrants. Right now / tonight might be the most convectively-active 01Q will be unless it's able to drift west and maybe re-organize/coalesce a bit with the help of the slightly warmer waters of the Brazil Current. On this current southward trek, it'll be moving over increasingly cooler waters (from 24C today to closer to 22C tomorrow). In terms of satellite appearance, 01Q evokes a storm that's on the cusp of transitioning from a subtropical to a tropical system.

Source: SSEC RealEarth