That is the sufficient quantity of disaster supplies the Department of Homeland Security recommends having on hand in case of an emergency. After an emergency occurs, it could be hours or even days for first responders to reach you.
Fortunately, in most cases, such as hurricanes and blizzards, people are given some forewarning of what’s coming and when. You have time to prepare. But what if you are in the middle of potential trouble and don’t know it yet?