Water Leak After Rain in Front Passenger Floorboard

I have water to accumulate in the passenger side front floorboard after a heavy rain. I do have a sunroof but, I have checked the drains and cleared those (had that problem last year). I'm not sure where the water is coming in from since the area that I was getting the water into the car from the sunroof drain issue is bone dry. If it's not raining outside, it dries up after a couple of days with me sopping the water up with a shop vac and towels. The water is not discolored and doesn't smell like anti-freeze. Any ideas on how to fix this would be greatly appreciated.