Complex sentence: As Typhoon Amber drifted inland over Eastern China, while maintaining Tropical Storm strength, Cass was pulled very close to Typhoon Amber, which severely weakened Cass, as it made landfall on August 30.
Split into simpler sentences: As Typhoon Amber made landfall, and moved inland over Eastern China, Cass was pulled very close to Typhoon Amber, while Cass was maintaining Tropical Storm strength. This severely weakened the storm, as it made landfall on August 30.