After the weather we've had the last few months, it's an especially good idea now to have an emergency preparedness plan. We personally keep on hand a way to filter water, as well as some canned and dried foods in case we are left without power. My husband and I also carry emergency blankets (the thin little mylar ones), a pocket knife, our phones, my husband a portable charger, matches and a lighter, a first aid kit (a mini one for me, a larger one on my husbands larger bag), paracord, snacks, and more. In our car we have two gallons of water we rotate out, a change of clothes for each of us, and a small supply of cloth diapers. We have a set meet-up location if necessary, as well as plans for different severe weather that would require us to stay put (like tornado's).
You never know what is going to happen, and don't have to be a doomsday prepper to be prepared. If a tornado hits, we still have a way to make sure everyone is okay and have immediate needs met. If the power goes out in the middle of winter due to a class 3 snow emergency ice storm (as has happened in the past), we can still stay warm and fed. The idea is similar to having a fire extinguisher in your kitchen, or a conceal carry license. You don't have it because you ever expect to need it, but because you realize things can happen and it's better to not be caught unprepared.
The blog Pinch a Little Save a Lot has a free downloadable emergency planning kit. You can use parts of this for nearly anything, including the emergency contacts for a babysitter or the wallet cards to give to your kids to remember who to call in an emergency. It also has tips for creating a plan for your family in case of an emergency. Downloads are available for free here: http://pinchalittlesavealot.blogspot.com/2012/03/free-family-emergency-planning-kit.html