WASHI developed as a tropical depression over the South China Sea about 450km south-southeast of the Macao(near 18.5¢XN, 115.0E) around 12UTC on 28th July and moved generally to the west slowly.
Around 18UTC on 28th, WASHI located near 18.7¢XN, 114.1¢XE and moved to west-northwest at a speed of 13km/h. It then passed by the South China Sea, which is the shortest distance (about 370km) away from Macao in the early morning on 29th and approached Hainan. By 12UTC on 29th, it intensified into a tropical storm near 18.5¢XN,111.7¢XE, with central pressure of 992hPa and central maximum wind of 65km/h.
After that, WASHI still moved in a steady speed in the direction of west-northwest and made landfall over the east coast of Hainan in the morning of 30th. It then entered Beibu gulf in the nightfall and made second landfall over northern Vietnam in the noon of 31st. WASHI weakened into a tropical depression near Ha Noi that night and dissipated gradually.

Record of tropical cyclone signal hoisting:
 
DATE
TIME
HOISTED SIGNAL
29 / JUL
11:45
The standby signal No. 1
30/ JUL
09:30
All signals were lowered