Complex sentence: Later that day, the system started to rapidly intensify as an upper level trough approached the system, before during the next day the JTWC reported that the system had peaked with 1-minute sustained windspeeds of 230 km/h (145 mph).
Split into simpler sentences: Later that day, the system started to rapidly intensify as an upper level trough approached the system. During the next day the JTWC reported that the system had peaked with 1-minute sustained windspeeds of 230 km/h (145 mph).