A large amount of rain occurs off the coasts of the Maritime Continent islands. Much of this rain happens at night as storm systems initiate near the coast and move away from the shore soon after sunset. Many mechanisms have been suggested to explain the initiation and continued development of these storms, which can propagate hundreds of kilometers from shore. This presentation will show results using a novel tracking technique applied to satellite rainfall data to identify individual storms off the coast of West Sumatra over a year period and determine their speed, lifetime, intensity, and other characteristics. We find that the nighttime offshore propagating rain events only occur about a third of the days in a year, while many of the postulated mechanisms behind their formation occur daily. We also find that the offshore events can vary significantly in propagation speed and structure from one another, suggesting different mechanisms at play in their evolution.