95 Celica Door mechanics

I need some help and/ or dirrection for a problem that just popped up yesterday. For a little insight, it has been raining every day for the past two weeks here so that may have something to do with it. It seems that my 95' Celica's dirver side door manually locks when I lift the handle. It is not an activation of the auto locks, and if I keep the key turned to unlock and lift the handle it opens just fine. I want to open-up the door pannel this weekend and correct the problem, but I really am not sure what to look for.

Any advice would be of great help and appreciation,

Until,
Icthulu