My current thought is to lie down in the walk-in closet closest to the center of the house. The experts suggest throwing a mattress over the body for protection. Mine is too heavy and I am not going to take the time for this. So, I have been looking for other lighter protection mats to use. I found this tornado shield sleeping bag that sounds like a good idea but has not made it into production.
Tornado Shield helps protect against storm-flung debris
Another is this storm guard blanket. As the cost is a little high I am still looking.
BODYGUARD™ by ProTecht