A family walks home from the grocery store in Lancaster, Pennsylvania, in 2010. Carolyn Kaster / AP Lines of frantic shoppers have mobbed grocery stores in Washington, DC, after the National Weather Service gently advised residents on Wednesday that an intense weekend storm will pose “a threat to life and property” and impact “you, your family, and your community.” Which led me to wonder: After people hear a message so ominous, and after reminders of their employers’ inclement-weather policies hit inboxes, what do they buy to prepare for spending a good deal of time indoors?