U.S. storm Andrea stronger, heading towards Florida Big Bend: NHC Thu Jun 6, 2013 5:15am EDT (Reuters) - A tropical warning has been extended from Ochlocknee river to Indian Pass, Florida, as tropical storm (TS) Andrea, which has strengthened, heads toward the Florida Big Bend, the U.S. National Hurricane Center said in its latest advisory. Andrea is moving towards the north-northeast at nearly 13 miles per hour (20 km per hour), with maximum sustained winds near 60 miles per hour (95 km per hour). A turn towards the northeast with an additional increase in forward speed is expected today, the NHC said. A tropical storm warning is in effect for the west coast of Florida from Boca Grande to Indian pass, Flagler Beach Florida to Cape Charles Light, Virginia, Pamlico and Albemarle Sounds and lower Chesapeake Bay south of New Point Comfort, the agency said. Reporting by Shruti Chaturvedi in Bangalore; Editing by Greg Mahlich