I would think in Al he would be concerned about tornadoes.
One thing you do not want is electricity. In that concrete box if it did have an electrical surge from lightening...could get rather exciting in there.
You can move it if you like my idea, but I thought about doing this by putting it just outside of my bedroom so I could build a staircase going down to it. If in the middle of the night a storm hit, easy to dive in the hole without running out in the storm. And build the doors and staircase class5 storm certified. Might even have an outside door too for access if outside. Middle of the night storms would be my worry.