(CNN)Category 3 Hurricane Matthew has left more than 1 million people without power in Florida as it skirts the state’s east coast, but the most damaging blow to the Southeast could still be to come. The storm — centered just off the northeast Florida coast Friday afternoon — threatened to push dangerous storm surges into Jacksonville with or without landfall and eventually communities along coastal Georgia and South Carolina. Although projections showed the storm still could go out to sea without landfall, its center very well could cross land with devastating effect, if not in Florida, then in Georgia or the Carolinas.”(Matthew) will move into land at some point … because the coast turns (east) before it will,” CNN Meteorologist Chad Myers said.Matthew — with winds of 115 mph at the center — hit the east-central coastline with gusts of up to 83 mph after running parallel to the coast much of the day, leaving debris and some street flooding behind. Parts of St. Augustine flooded even as the hurricane was still approaching. A virtual river of water rushed past a bed and breakfast business in the city about 35 miles southeast of Jacksonville, according to video posted by reporter Russell Colburn of CNN affiliate WJAX. “20 people, including children, stuck in #StAugustine bed &breakfast. They say they’re getting worried, as the surge is about to come in,” Colburn posted on Twitter. Special concern surrounded Jacksonville’s St. Johns River, which could be overwhelmed by water pushed into it by the storm.