ADVANCE FOR USE TUESDAY, DEC. 22, 2015 AT 3:01 A.M. EST (2201 GMT) AND THEREAFTER; THIS STORY MAY NOT BE PUBLISHED, BROADCAST OR POSTED ONLINE BEFORE TUESDAY, DEC. 22, 2015 AT 3:01 A.M. EST (2201 GMT) - In this Nov. 12, 2015 photo, power poles are seen outside the Waveland power substation for Coast Electric in Waveland, Miss. "We're only a few feet above sea level right here," says Scott Brown, vice president of engineering for Coast Electric. An Associated Press analysis of industry data found that severe weather is the leading cause of major outages on the nation's power grid. (AP Photo/Gerald Herbert)