Complex sentence: On August 28, an area of disturbed weather that had lingered east-northeast of Saipan became better organized, and the JTWC began issuing warnings on Tropical Depression 10W the next morning.
Split into simpler sentences: On August 28, an area of disturbed weather that had lingered east-northeast of Saipan became better organised. The JTWC initiated warnings on Tropical Depression 10W the next morning.