i would make the current day's forecast bigger, since that's probably what most people want to see. the current conditions are not as important since you can easily see whether it's currently raining or whatever without going to the site.
also, what kind of comments are you expecting for visitors to leave? i would think that spammers would quickly fill them up with junk and drown out any useful ones, but i can't really think of what useful comments others would want to read on a weather site.