Tire/tube problem
So last night I went for a wet ride on my road bike in the remnants of Hurricane Isaac. Along the way, I hear a rhythmic "sss...sss...sss...sss" that sounded like it was coming from the rear tire. I also thought a felt air blowing onto my right leg. So I figured I had a pinch flat a pulled over. The tire felt like it had plenty of air though, so I rode another 4 miles or so. Today, I did not ride, but I noticed the that the rear tire was flat. I took the bike out to the garage and aired up the rear to about 120 psi. It seems to be holding air for the time being.
Any ideas on what the problem could be?