How is the surf in the summertime in South America's east coast?

I'll be around Argentina, Uruguay and Brazil and was wondering what the quality of surf will be in the months Dec-Jan (southern hemisphere summer). The way it's shaped seems like it'll miss out on any northern swell action, and that southern swells must be weak that time of year.... but then again, I've only been a west coast surfer, and therefore don't know much about the atlantic.