Complex sentence: Hurricane Dean's remnant low pressure system then drifted north into southern California, bringing thunderstorms to northern San Diego County, and over 2 inches (5 cm) of rain to Lake Wohlford.
Split into simpler sentences: Hurricane Dean's remnant low pressure system then drifted north into southern California. Thunderstorms occurred in northern San Diego County, and over 2 inches (5 cm) of rain fell at Lake Wohlford.