Mobile service stops working in disasters

One of the things that almost always goes in a natural disaster is the mobile phone service. You should have an alternative way of communicating with family and friends. Work with those you need to prior to a disaster to come up with a good communication plan. Potentially meet somewhere given a situation. For example my wife and I have agreed if there is a tornado during the school hours that we would both go to pick them up and meet in a particular area.