Complex sentence: Iris then moved to the west-southwest at 12 mph (19 km/h), the change in course was due to the interaction with Hurricane Humberto which was 750 miles (1207 km) away.
Split into simpler sentences: Iris then moved to the west-southwest at 12 mph (19 km/h). The change in course was due to the interaction with Hurricane Humberto which was 750 miles (1207 km) away.