Torrential rainfall across the northern Philippines, including the capital city of Manila, has led to widespread flooding problems since the weekend.
Former Typhoon Usagi passed north of the Philippines on Friday before moving westward and making landfall in China on Sunday.
Many times when a tropical system takes this track, the southwest monsoon will be enhanced leading to widespread flooding in the northern and western Philippines.
This was the case in August when Tropical Storm Trami enhanced the monsoon resulting in deadly flooding across Manila with as much as 40 inches of rainfall in some parts of metro Manila. The disaster resulted in at least 16 deaths.
http://www.accuweather.com/en/weather-news/typhoon-enhanced-rainfall-floo-1/18115630