sentences:  Around this time, the storm started to move along the western edge of the ridge that previously steered it towards the west-northwest, causing Guillermo to turn northwest.On August 9, the storm crossed longitude 140°W, denoting a shift in warning responsibility from the NHC to the Central Pacific Hurricane Center (CPHC).Not long after crossing into the CPHC's area of responsibility, the storm further weakened to a tropical depression as it moved over waters.