A general question about hurricanes

[oldnavyguy]

As I am new to this site (and forums in general) please forgive me if this is not the correct forum to bring up this question of mine. Just let me know and I'll immediately move to the right forum.

Could someone explain to me why I never hear of hurricanes bearing down on the coast of Brazil or Argentina? Do hurricanes exist in the South Atlantic? Obviously they do in the North, and their sister (or brother) storms, Typhoons, are in the North and I think South Pacific, but I never remember hearing of them in the South Atlantic.

I always thought weather was essentially symetrical about the equator (albeit 180 degrees out of sync our summer their winter etc.).

A student I work with intorduced me to the site and I have become facinated with the level of my ignorance. I'll be asking more simple and ignorant (but I hope not stupid) questions.

Thanks.

[Canelaw99]

They don't usually form there, but in 2004, there was one - here's an article on it:

http://www.metoffice.com/sec2/sec2cyclone/catarina.html

[WmE]

They are very rare, because in the South atlantic there are generally very unfavorable Upper level winds, quite cold SSD and a lack of disturbances because there's no ITCZ.

[x-y-no]

In general, the conditions for the formation of tropical cyclones don't obtain in the South Atlantic. One major reason for this is the way the large-scale currents flow in the oceans. There's a very large net transport of warm water northwards across the equator in the Atlantic basin, which leads to the North Atlantic surface waters being substantailly warmer - particularly on the westerns side due to rotational dynamics.

The dispalcement of the mean convective maximum due to this heat transport also means that the ITCZ is located in the Northern hemisphere for most of the year.