You should read on Jerry's site his discussion about indoor lighting. Ficus will survive in low light conditions, but they do not thrive there. They need bright light to grow well, with short internodes. I put my ficus in full sun (shade in afternoon) all summer, from May until October. They really love that time outside, and grow profusely. When I bring them inside, however, they slow to a crawl. If I had Jerry's light setup, I'm sure they would keep growing well, but I cannot provide that amount of light.
Considering where your tree is located, you will need much, much more time to develop it. The tree will have longer internodes and larger leaves, and will grow much more slowly without the sun. It will take a very long time to develop into a bonsai.
Believe me, I understand about storms. I grew up in Southeastern Kansas, in "tornado alley." When I expect severe storms, I try to put my trees under their benches or under the eaves of the house. The better ones, anyway. I have found that this practice has effectively prevented severe weather such as hail. I am also quite sure that if I left out even one nicer tree, the whole city would be pelted.
You just have to decide what your goals are, and then provide the environment for the tree that it needs. I wish you well!