Tornadoes and storms in dreams is a symbol for anticipation of catastrophe (this is emotionally related, or related to life in a general sense). The first dream holds a building (your body) standing alone on its own. The small tornado threatens the school(you) but doesn't really do anything. It seems you have a little bit of protection here, too (the fencing), though you're still out in the open(vulnerable). In the second dream sequence the same storm comes up, but now you have the change of perspective - attributes and responsibilities attributed to your loved ones. The second tornado greatly overpowers the first tornado, and does far more damage.

I see a theme here of looking back on simpler times (the "back in the day" one room schoolhouse, for instance). When things happened, not much damage was done. But now we have a much more complicated life. There's a husband and kids that count on you. And the storms are bigger, too. Things get wiped out. But in the end, I think is what's most important - You were still alive to see the flattened destruction after the storm passed.