Jerry,
A common problem on the Monaco slides is the pooling of water on the topper awnings. All of the pooled water releases at once and comes down like a waterfall. The slide seals have a hard time dealing with that much water all at once. If your slides have dropped some in the opening, This problem just becomes worse as it can leave gaps in the wiper seals.
When you know a severe storm is coming, you may want to take some measures to see that water doesn't pool on your topper awnings. Also, depending on how old your topper awnings are, they may have shrunk some allowing this pooled water to fall directly on the slide roof.
If you find that your slides have settled, query the forum regarding this problem and you will find an excellent entry from Ed Buker along with pictures on how to fix it. However, this will probably be something you want a shop to do.
Given the age of your coach, you may want to have a reliable shop evaluate your slide adjustments anyway, but I would try the awning suggestion first to see if that doesn't solve your problem.
As others have said, slide leaks happen to all of us.
Good luck my fellow chief,
Bill (MCPO, Retired)