Complex sentence: The southern islands of the Solomons chain were seriously affected by the passage of tropical cyclone Namu in May 1986, where it was considered the worst tropical cyclone to impact the area in five years.
Split into simpler sentences: The southern islands of the Solomons chain were seriously affected by the passage of tropical cyclone Namu in May 1986. There, Namu was considered the worst tropical cyclone to impact the area in five years.