Complex sentence: Over the next couple of days the disturbance moved towards the southwest and gradually developed further before early on December 28 the Tropical Cyclone Warning Center in Nadi, Fiji (TCWC Nadi), started to monitor the disturbance as a tropical depression.
Split into simpler sentences: Over the next couple of days the disturbance moved towards the southwest and gradually developed further. Early on December 28 the Tropical Cyclone Warning Center in Nadi, Fiji (TCWC Nadi), started to monitor the disturbance as a tropical depression.