Complex sentence: On September 14, Julia attained hurricane status and subsequently entered a trend of rapid intensification; the storm strengthened from a minimal hurricane to a low-end Category 4 in only 24 hours.
Split into simpler sentences: On September 14, Julia attained hurricane status and subsequently entered a trend of rapid intensification. As a result, Julia strengthened from a minimal hurricane to a low-end Category 4 in only 24 hours.