WOFATI and tornado safety

I'm looking for more information on wofati and how they hold up in tornadoes.  I *think* I am going to dig out as deep as a basement that I can then back fill around the building to have it surrounded by earth on three sides. How do I ensure the open face of the house would not be at risk during storms?

I think wofatis, by their nature, are exposed on two sides.  And they aren't really underground, they're just built into a hill with earth on top and on the two sides.

Tornado wise, I'm guessing the roof would be just fine but the glass would be a clear risk for flying cows or telephone poles.  I'm not sure how you can remedy the window risk without going to hurricane mitigation techniques.

Impact resistant glass and doors and/or shutters.

I thought only the 'face' of the house was exposed and the rest was underground? I'm thinking I need to learn a lot more about building a WOFATI and fast!

Here ya go

Paul's WOFATI article

It would not ge my first choice to deal with a tornado. To mitigate somewhat, build on the east side of a hill below the crest. Of course, this is a trade off, but it does add a little to the safety factor.

WOFATI should be very safe as long as the tornado approaches from any angle other than directly at the face.  In a heavy tornado area, I wonder if a series of WOFATI could be built with the flat sides all facing one another?  Not practical for most people I think, but may work for small communities.  Short of that, building a berm in front of the WOFATI that was slightly taller should ensure that a tornado coming from that direction passes over the WOFATI.  Dome shaped objects do well in tornadoes because the force of the wind travels along the ground, wiping out everything in it's path.  Structures that deflect the wind over or around them are generally unharmed, the same way a tornado will pass over a slope or a hill without tearing a path through it.