Complex sentence: When Gener left the PAR, it left a large mass of wind standby over the South China Sea, which will be later triggered by the Typhoon Haikui to cause the immense raining in August 6.
Split into simpler sentences: When Gener left the PAR, it left a large mass of wind standby over the South China Sea. It would be later triggered by the Typhoon Haikui to cause the immense raining on August 6.