BIRMINGHAM, Ala.—Storms that left splintered homes and broken trees across Alabama and Mississippi moved into Georgia and Florida on Thursday, rousing residents with early morning warnings as forecasters said the threat of dangerous weather would move up the south Atlantic seaboard. About 20,000 homes and business were without power and the weather service said at least two people were hurt when an apparent tornado struck southwest Alabama, destroying a house, but the region appeared to escape the kind of horrific toll many feared after ominous predictions of monster twisters and huge hail. “Overall, we have a lot to be grateful for, as it could have been much worse,” Alabama Gov. Kay Ivey said in a statement. Forecasters issued a string of tornado warnings around the region where Alabama, Georgia, and Florida intersect, but there were no immediate reports of major damage. The National Weather Service office in central Alabama said …