“Wuthering Heights is one of the few operas by Carlisle Floyd that isn’t based on an explicitly American story. Emily Brontë’s novel is set in Yorkshire, amid the moors that give the tale its famous atmosphere. But whether it’s English gothic or Southern (American) gothic, Floyd has a way with stories drenched in melodrama and mysticism. … But the real star here is conductor Joseph Mechavich, who guided the orchestra and voices through Floyd’s often…