A strengthening storm system will spread heavy rainfall across the Yangtze River Valley from Friday night through Sunday night.
Along this path, the major cities of Chongqing, Wuhan, Nanjing and Shanghai can expect locally heavy rainfall. Some thunderstorms embedded in the rainfall will produce strong winds and even hail, but flooding appears to be the primary concern at this point.
The storm will track from west to east bringing the heaviest rainfall to Chongqing Friday night into Saturday and Wuhan Saturday into early Sunday. These areas can expect a general 1-3 inches (25-75 mm) of rainfall with locally higher amounts possible.
The storm will impact Nanjing Sunday into Sunday night with 1-3 inches (25-75 mm) of rain while Shanghai will experience a period of heavy rainfall late Sunday into early Monday. The worst of the storm is expected to miss Shanghai with rainfall averaging 1-2 inches (25-50 mm).
Since all of these major cities are located along the Yangtze River, flooding is always a major concern when a heavy rainfall event is expected.
In 1998, a prolonged period of flooding along the Yangtze River resulted in 3,704 deaths, while millions were homeless at some point during the flooding.
Farther south, a line of heavy thunderstorms with damaging winds will be possible Saturday night into Sunday from Guizhou province into Hunan and Guangxi provinces as the cold front presses southward.
The front is expected to weaken before reaching Hong Kong early next week. Ahead of this front, there will be the possibility of scattered showers and thunderstorms each day. Due to the recent heavy rainfall across the area, any thunderstorms could result in flash flooding problems.