Why are there no storms WEST of South America?

[winter123]

I realize there are non east because it's a small, cool basin. But west? Shouldn't it be equivalent to the China/Japan coast in the Northern Hemisphere?

http://upload.wikimedia.org/wikipedia/comm...racks-edit2.jpg

[aslkahuna]

There's some mightly chilly water off the West coast of South America most of the time. Also, Japan and China are on the EAST side of the Eurasian Continent so there's no comparison there.

Steve

I'd say la nina has something to do with it?

[winter123]

QUOTE (aslkahuna @ Jan 2 2008, 02:00 AM) <{POST_SNAPBACK}>

There's some mightly chilly water off the West coast of South America most of the time. Also, Japan and China are on the EAST side of the Eurasian Continent so there's no comparison there.

Steve[/b]

Everything in the Southern Hem is OPPOSITE of the North, in case you forgot.

[NDG]

Waters are way too cold as Aslkahuna said, and you can not say that coastal western S America is the equivalent to that of coastal Japan and Asia, tropical easterlies are in the southern hemisphere as well, it is not the opposite. In another words, any tropical formation to the west of S America in the southern hemisphere would move towards the west away from S America most of the times.

[MatthewCarman]

No storms east of SA? Cyclone Caterina hit SA's east coast and had 1 minute sustained winds at 100 MPH, caused almost 400 million in damages and killed 3-10 people. I think it came ashore on Brazil. So they get storms to and they do have a tropical season which Caterina was part of. Storms and Hurricanes are just not as common in that area.

[aslkahuna]

The flow patterns in the Southern Hemisphere are NOT the opposite of the Northern Hemisphere flow-only the sense of rotation is. You have the same zones of windflow as we do up north including the mid-latitude westerlies and the Trade wind easterlies. The difference being that the Southern Hemisphere Trades are Southeast rather than Northeast. If you look at the western coasts of the Continents in the Southern Hemisphere, you will find the same upwelling patterns you find up north due to the presence of the oceanic subtropical Highs. Again the difference being that the windflow is SW rather than NW. This upwelling is especially strong off the coast of South America which explains the presence of cold water there. Though modulated by the ENSO oscillation, the presence of cold water is not due to any phase of the ENSO but rather to the Planetary Circulation just as the cold water off Baja and CA is. Again to reiterate, although the sense of rotation of features is opposite to that in the northern hemisphere, the general flow pattern is not and the rules governing what happens on the coastal margins of the Continents are the same therefore, one can not compare the WEST Coast of South America to the East coast of Asia (or Australia and Africa for that matter)

Steve, why is it harder for southern storms to form? Like you said from cold water? but is there more shear?

[winter123]

QUOTE (aslkahuna @ Jan 2 2008, 07:37 PM) <{POST_SNAPBACK}>

The flow patterns in the Southern Hemisphere are NOT the opposite of the Northern Hemisphere flow-only the sense of rotation is. You have the same zones of windflow as we do up north including the mid-latitude westerlies and the Trade wind easterlies. The difference being that the Southern Hemisphere Trades are Southeast rather than Northeast. If you look at the western coasts of the Continents in the Southern Hemisphere, you will find the same upwelling patterns you find up north due to the presence of the oceanic subtropical Highs. Again the difference being that the windflow is SW rather than NW. This upwelling is especially strong off the coast of South America which explains the presence of cold water there. Though modulated by the ENSO oscillation, the presence of cold water is not due to any phase of the ENSO but rather to the Planetary Circulation just as the cold water off Baja and CA is. Again to reiterate, although the sense of rotation of features is opposite to that in the northern hemisphere, the general flow pattern is not and the rules governing what happens on the coastal margins of the Continents are the same therefore, one can not compare the WEST Coast of South America to the East coast of Asia (or Australia and Africa for that matter)[/b]

Ok, I get it now, thanks. Cold water because of ocean currents is the main factor? Or is it shear too as dustin asked?

Interesting image:
http://upload.wikimedia.org/wikipedia/comm...rrents_1943.jpg

[aslkahuna]

Cold water and shear are the main obstacles to development around South America. The Southern Hemisphere is a mostly oceanic Hemisphere so the mid latitude westerlies do not shift as much durng the seasons as they do in the Northern where most of the Earth's landmasses are located. It is, in fact, this disparity between the land areas of the two Hemispheres that gives rise to the the large monsoon circulations and the cross equatorial flow that characterizes them. Yes, we do on occasion have Tropical systems that develop off the east coast of South America though very infrequently but the question was in reference to the West coast.

Steve