I'm not sure if there is a single all-encompassing resource. The [wiki]Meteorology/Everyday Weather[/wiki] is pretty good, and soinc.org links to a NOAA site
that has lots of resources directed at Science Olympiad. Other than that, you may just want to use different sites for different topics, since some might focus on, say clouds, while others might focus on fronts. This will give you a more diverse background.
Also, a quick tip. You might want to put your image and the other information in your signature. To do that, you can click on "User Control Panel" on the upper right, and then the "Profile" tab, and finally "Edit signature". Then that signature will appear under all of your posts.
Also, I see you're from Wayne Highlands! Good job last year, it was quite impressive how you finished second at regionals. NE is shaping up to be a dogfight this year in Division B.