Check out this new article Wizards of the Coast posted recently:

The Storm Bird

The residents of Sword Coast ports are accustomed to putting their heads down and riding out lashing storms from time to time, but they seldom have to contend with skyships hurtling overhead during such weather. Yet in the last three successive storms, a hitherto unknown skyship clearly lettered The Storm Bird has crashed through rooftops and chimneys in Waterdeep, fighting the storm to reach some destination in the city.