Exploding Sourdough Starter

[Tejon]

Hi,

I got a new sourdough starter going the other day. Everything was going just like it usually does. I checked it yesterday and it was nice and bubbly, but I decided to give it one more day to develop before I baked with it just to be sure. I fed it with a little flour and covered the quart jar it's in with a paper towel.

This morning I came out and found that almost all of it had bubbled out of the jar overnight (like three quarters of the volume of the starter). This has never happened to me before. I assume that it's fine and that I just came into contact with an especially virulent strain of yeast, but I wanted to check in here to see if anyone's experienced something like this before. Everything smells fine and I just added a cup of flour and another of water.

Any advice? Thanks a lot in advance.