EMP is possible via a non-domestic anti-government entity(we call them terrorists, the feds call us terrorists now). Pretty low tech stuff that can cause chaos. We're always a breath away from a pandemic of some kind. Lord help us if ebola ever breaks loose from Africa. There is new speculation the black death from the dark ages was caused from an ebola strain, not the plague. The death toll from those outbreaks speak volumes. Financially, our economy is a ticking time bomb. Look at other countries, and the disorder that came about from cuts in handouts, or even worse, collapse of the government. People here expect it cushier than overseas. Expect carnage when the FSA can't get their obamaphones and Obama credit cards to work. Racial tensions are brewing. Although such problems tend to stay around larger cities, look at Sarajevo, and other enclaves in the former Yugoslavia. Down the road, it is always a possibility, but kind of remote. Natural disasters, we have a slew that can happen. Some could be ELE. Mt Rainier, and the subduction zone off the pacific coast is one of the worst case scenarios we could see in our lifetimes. We could only hope kali. slides off into the ocean from the fault systems down there. New Madrid fault could rip the midsection apart. Several major cities are vulnerable to total destruction as of right now. Major snowstorms, flash flooding, twisters, and hurricanes as well. Then of course, there is Yellowstone. Aside from weather events and Yellowstone, major disasters that affect other parts of the country could directly affect us here. With such large scale carnage, people have to go somewhere. Dallas became a haven for some real scum bags after Katrina and Rita, and it wasn't safe to wander around after dark, and questionable during the day.

You have to plan for an event that may require you to hole up inside your house, as it isn't safe or possible to travel outside of your area. Power, water and phones may be down. You need to a means to overcome them.
You also need to plan for an event that may lead you to abandon your home. Maybe it was damaged by weather, etc, or the area is too unsafe. You need a means to travel out of the area, being secure in doing so, as you may become a target by different entities. You'll need food, fuel and water, and a way to communicate. You'll either be going to a neighboring town, or village, or a safe spot you have already picked. One there, you may need to be self sufficient.
Lastly, you want a plan for a situation where your entire area is too unsafe, whether it be political, weather, or geologic in nature. You may have to leave the area completely, and go to a different state or part of the country, where there may be friends or relatives that are allied with you. Such a trip will require you knowing how to find sources of fuel for transportation or having a stash to make it to your destination. The trip may seem like nothing more than a vacation trip under stress, to bordering a zombie apocalypse riddled with danger. Protection would be a must in planning, as well as being able to navigate without electronic help. In any of the scenarios, you need to know who is like minded and trustworthy, and pool resources in some situations. Phone systems crash during the slightest emergency. Phones and the internet can be turned off at the king's whim. If you need to evac the area, you'll want to let someone know you're coming. If you can't leave your house, you need a way to contact others.