Subtropical Storm Arani

[Somerset Squall]

The rare invest 90Q has become a subtropical depression this morning, with intensity at 30kts. The system has been over land over the last few days but has emerged over warm water and developed further east of Compos dos Goytacazes, Brazil. 01Q is moving eastwards and should continue to move away from land. Shear is moderate, but still unusually low for this usually hostile basin. Waters are very warm, around 28-29C. With this in mind, I think 01Q will become fully tropical. Just how strong it will get is open to question. Current pressure is 1000mb and falling, indicating 01Q is intensifying.

[Cookie]

Became subtropical storm Arani

[summer blizzard]

Very suprising. The sat images were rather poor when it was declared an invest.

[Gray-Wolf]

Is this now 3 in 5 years? I was always lead to believe they just couldn't form there and this 'belief' held true up to 5 years ago!

[Somerset Squall]

Indeed GW, something strange is going on. It was thought lack of tropical disturbances and high shear would make development impossible but this is clearly not the case.

01Q, as Cookie states, was named Subtropical Storm Arani last night. Arani looked close to becoming fully tropical but convection remained slightly detached east of the LLC. Arani has strengthened nonetheless and has sustained winds of 45kts near the centre. The environment around Arani is deteriorating however, as a trough to the west is creating strong shear over the storm. The LLC is entirely exposed in latest imagery and if shear doesn't let up, Arani will be a goner as it continues to move eastwards away from the coast.

A rare beast, but are these creatures becoming less rare?

[Cookie]

not quite as good as earlier

[Cookie]

Waves cause by Arani

[Somerset Squall]

Awesome image Cookie!!

Convection has completely dissipated over Arani, and the system is well on the way to becoming extratropical over cooler waters and high shear.

[onlyME]

Here's link about South Atlantic (sub)tropical cyclones.http://en.wikipedia.org/wiki/South_Atlantic_tropical_cyclone

Hope it'll be useful

[knocker]

Some quite interesting stuff on Arani.

http://www.nasa.gov/mission_pages/hurricanes/archives/2011/h2011_Arani.html

[Cookie]

Some quite interesting stuff on Arani.

http://www.nasa.gov/mission_pages/hurricanes/archives/2011/h2011_Arani.html

thanks for sharing