I recently had what I think is the same issue on a phone that I was fixing for somebody else (Google search listed this post in one of the results). In my case it turned out to be the 360 Security Pro app which has a new feature that was enabled called "Intruder Selfie" where it activates the front facing camera to take a photo if the applock pattern is entered incorrectly 3 times. You can disable this feature in the AppLock settings for 360 Security.

I'm not sure about the weather notifications, but I suppose you can check whether there are any widgets or other apps enabled or updated recently.