sentences:  Additionally, a low pressure system developed within the disturbance by July 29.The following day, the system became sufficiently organized for the NHC to classify it as Tropical Depression Nine-E; at this time the depression was situated roughly 345 mi (555 km) south of Salina Cruz, Mexico.In response to a deep-layer ridge to the north, the depression tracked at a steady pace towards the west-northwest, and this motion persisted through the first week of August.