The Weather Observer was the first of the post-war UK Ocean Weather Ships.  She was converted to the Weather Observer at H.M. Dockyard Sheerness and renamed on 31 July 1947 by the Secretary of State for Air in Shadwell Docks, London and sailed in 1947 to take up her station in the North Atlantic.

You can read more about the history of weather ships online here and also in this book.