Unidentified vocalization

Around mid-week, Wednesday, August 19th, we finally got some rain.  It has been dry for awhile and my grass is brown and crunchy.  

The rain came at night, starting around 1:00 am and continued off and on, sometimes heavily, until morning.

I keep my bedroom window wide open and as the rain began I heard a loud vocalization that seemed mostly bird-like to me.  It awakened me - perhaps not fully - but out of habit I found myself running through familiar bird songs and calls in my head.  I could not match it with any.

I'm a restless sleeper.   Around 3:00 am I was reawakened by the rain coming down harder and I heard the call again. This time I was ready. I got my cell phone and made these two recordings from my 2nd floor bedroom window.  Unfortunately, the loud volume of the calling is diminished by the heavy rain.

I was focused on the vocalizer being a bird.  But yesterday - 8/29/15 - I went through a variety of frog vocalizations with friends.  While we couldn't match it up with any, this exercise made me be able to think more broadly and I've edited this post to consider non-bird vocalizers.

The first video is 10 seconds and the second video is 12 seconds.   Have your volume turned up.  Any help with the identification of this vocalizer would be appreciated.