Complex sentence: Early on August 3, Colin's forward motion increased exponentially, and the cyclone was unable to maintain a closed circulation; it degenerated into a trough at 1800 UTC, although tropical storm-force winds persisted.
Split into simpler sentences: Early on August 3, Colin's forward motion increased, and the cyclone was unable to maintain a closed circulation. The tropical storm degenerated into a trough at 1800 UTC, although tropical storm-force winds persisted.