This may help you a bit. We live in a condo style houses. Out in the streets there are the man hole cover that contain all the cables for internet and phone and whatnot. Everytime when it was raining, the internet, phone, and whatnot always cut out for a few hours till it dried up. What would happen is the rain would get inside the covered manholes and get inside the capsule that contains it all and shorts out everything. One day (when it was raining), AT&T came out a replaced all of the capsules containing the wires. I think at this time they also installed fiber optics if that makes a difference. Ever since then we havent had a problem with anything cutting out.
This may help you, just wanted to share it with you as you may be having the same problem.