Was checking around the new App World and found Weatherbug Elite. It was $5, but when I owned the iPhone it was my favorite weather app so I went ahead and purchased it. No ads, which is nice.
There are pushed weather alerts that will arrive in either your mail box or calendar, and this is user selectable. One neat thing I really like is that it adds a temperature icon up by your clock. Now I can throw another app in the top row if I want to and still always know what the temp is outside.
Here's a couple shots of it on the Tour so you can see the little temp icon on different screens. So far, no memory leak, although it's only been an hour or so that I've had it running.