Something really unprecedent may happen in southeastern Brazil

From Weather Wunderground

www.wunderground.com...

An area of disturbed weather has formed off the coast of Brazil, near 18S 38W. This disturbance has the potential to develop into subtropical or tropical depression early next week. Satellite winds estimates from the WindSat instrument show an elongated area of converging winds, but no organized surface circulation. Satellite loops show little organization to the cloud pattern, and only limited heavy thunderstorm activity. Wind shear over the region is about 20 knots, which is rather high, and should keep any development slow. Sea surface temperatures are about 28°C, about 1°C above average, and plenty warm enough to support a tropical storm.

Several global models, such as the ECMWF, UKMET, and NOGAPS models have been developing this system in recent runs. Phase space diagrams form Florida State University confirm that this storm is expected to primarily be a warm-cored system, meaning it will probably be classifiable as a subtropical or tropical storm if it attains surface wind speeds of at least 39 mph. The system is capable of bringing heavy rains to the Brazilian coast while it is in its formative stages over the next few days, but I doubt that these rains would be heavy enough to cause flooding concerns. By Monday, the storm should be headed southwards or south-eastwards out to sea, and it appears unlikely that Brazil would see tropical storm-force winds of 39+ mph from this system. I give this storm a low (< 30% chance) of developing into a tropical or subtropical depression by Sunday.

Brazil has had only one landfalling tropical cyclone in its history, Cyclone Catarina of March 2004. Catarina is one of only six known tropical or subtropical cyclones to form in the South Atlantic, and the only one to reach hurricane strength. Tropical cyclones rarely form in the South Atlantic Ocean, due to strong upper-level wind shear, cool water temperatures, and the lack of an initial disturbance to get things spinning (no African waves or Intertropical Convergence Zone exist in the proper locations in the South Atlantic to help spawn tropical storms). Today's disturbance is located much closer to the Equator than where Catarina formed. Thus, it has warmer waters to work with, and potentially less wind shear.

Metsul site (in portuguese) is predicting there's a chance enormous, cathastrophic amounts of rain for the state of Espirito Santo.
See more at: www.metsul.com...]

You never know. Interesting though because I really never heard of any tropical depressions in south America.

I don't really think this is that breaking news worthy unless it turns into something like this.

The subtropical cyclone has turned into a tropical cyclone!!
This is the second registered tropical cyclone in brazillian history (the first one was catarina in 2004).
Furthermore, it's even more uncommon that this storm started in the southeast coast, what have never happened before.
The cyclone seems to be movinf off the coast, but if it change its path and reach land, the damage may be extremelly huge, since nobody here in Brazil is prepared for such an unusual event.
THings are really changing!

Um ciclone muito raro, extraordinário do ponto de vista científico para o nosso clima regional, ainda classificado oficialmente como subtropical pelos Estados Unidos, mas que pela nossa análise já evoluiu para tropical, segue atuando na costa do Rio Grande do Sul. Os mais recentes dados do chamado best track do sistema, do meio da madrugada, acusavam ele posicionado a 29,5 graus de latitude Sul e 48 graus de longitude Oeste, muito perto da posição anterior de seis horas de 29,9 graus Sul e 48,1 graus Oeste. Significa que o centro do ciclone pouco mudou de posição na madrugada, deslocando-se um pouco para Norte e Noroeste. Já as imagens de satélite, que oferecem uma idéia mais atualizada, acusam que o ciclone tropical começou a se afastar de forma mais vigorosa para Leste, distanciando-se mais do continente agora ao amanhecer.

Google translation

A cyclone very rare, extraordinary scientific point of view to our regional climate, still officially classified as subtropical by the United States, but for our analysis has already moved to tropical following acting on the coast of Rio Grande do Sul The latest data called the best track of the system, the middle of the night, accusing him positioned at 29.5 degrees south latitude and 48 degrees west longitude, close to the previous position of six hours of 29.9 degrees South and 48.1 degrees West . It means that the center of the cyclone's position had changed little in the early morning, moving a little to the north and northwest. Since satellite images, which offer an idea up to date, charge that the tropical cyclone began to move more forcefully to the east, away from most of the continent now at dawn.

www.metsul.com...



Mod edit: Added Google translation.
Please, always provide an English version, even if it's a bad Google translation.

[edit on 10/3/2010 by ArMaP]

Strange that there is so little news about it - in English at least!

I remember something similar to this Subtropical system occuring around these parts a few years ago, although it was cold-cored and not a convective system like this is.
South Atlantic systems are rare, yet interesting to watch.