China: Tropical Depression Pulasan tracking northwestward across Hangzhou Bay as of late Sept. 19 /update 4

Tropical Depression Pulasan is tracking northwestward across Hangzhou Bay late Sept. 19, having just passed over northeastern island areas of Zhejiang Province. As of 20:00 CST, the system's center of circulation was approximately 91 km (57 miles) south-southeast of Shanghai, China.

Forecast models indicate that the weather system will imminently make another landfall over Shanghai before weakening as it tracks northwestward and then northward into Jiangsu Province Sept. 20. Pulasan is expected to turn to track east-northeastward late Sept. 20 and will strengthen back into a tropical storm as it moves over the Yellow Sea Sept. 21, before making another landfall over South Joella Province in South Korea late Sept. 21. The system is expected to skirt along the southern coast of South Korea late Sept. 21-early Sept. 22 before tracking east-northeastward in the Sea of Japan parallel to Japan's Honshu Island Sept. 22. The storm is expected to weaken into a tropical depression before approaching Fukui Prefecture late Sept. 22. Some uncertainty remains in the track and intensity forecast, and changes could occur in the coming days.

The China Meteorological Administration has issued a yellow typhoon warning (the second lowest level on a four-tier scale); heavy rain is forecast in parts of Shanghai, northern and eastern Zhejiang, central and southern Jiangsu, and southeastern Anhui Sept. 19-20, with rainfall totals of 10-16 cm (4-6 inches) possible in southeastern Jiangsu and northeastern Zhejiang. Strong winds are forecast in northeastern Zhejiang, Shanghai, and southeastern Jiangsu and rough seas are likely over offshore waters of southeastern China. Yellow rainstorm and landslide warnings are also in place over parts of the affected area.

Authorities in Zhejiang Province have raised the emergency response for typhoon prevention to Level 3 on a four-tier scale. Over 70 ferry routes have been suspended across Zhejiang and over 350 vessels have been relocated to safe waters. Some rail services have been suspended in Shanghai late Sept. 19.

Sustained heavy rainfall could trigger flooding in low-lying areas and those with easily overwhelmed drainage systems. If weather conditions prove hazardous, localized evacuations, flash flooding, and landslides are possible.

Inclement weather could trigger localized business, transport, and utility disruptions, rendering some bridges or roadways impassable. Flight disruptions at regional airports and temporary port closures are also possible. Stagnant pools of water during and after flooding increase insect- and waterborne diseases, such as dengue fever, cholera, and malaria. Exposure to raw sewage and other hazardous materials mixed with floodwaters poses a serious health threat.