According to the National Centre for Hydro-Meteorological Forecasting, on Wednesday morning, Saudel was packing winds of 62-74 kph, equivalent to level 8 on Vietnam's scale, with gusts at level 9 over the northeastern waters of the northern East Sea. It was moving northeast at about 15 kph.
The storm is forecast to continue northeast at 5-10 kph by 4 am on September 3, with winds remaining at level 8 and gusts reaching level 10.
Saudel is expected to turn west-northwest and slow to around 5 kph by early September 4 as it moves over waters southeast of China's Guangdong Province. Its intensity is forecast to remain at level 8, with gusts at level 10.
By early September 5, the storm is expected to turn west-southwest and slow further to around 3 kph before weakening into a tropical depression over waters southeast of Guangdong.
The tropical depression is then forecast to continue west-southwest at about 3 kph and gradually weaken.
The storm is expected to bring winds of level 6-7 and gusts of level 8-9 to northeastern waters of the northern East Sea, with waves of three to five metres.
Near the storm's centre, winds could reach level 8 with gusts at level 10, while waves could rise to four to six metres, producing rough seas.
Vessels operating in affected waters have been warned of thunderstorms, strong gusts and high waves.
Meanwhile, hot weather is forecast across northern Vietnam and from Thanh Hoa to northern Quang Tri on September 2, with highs of 35-37 degrees Celcius and above 37 degrees Celcius in some areas. The heat in central Vietnam could persist until around September 4.
Scattered showers and thunderstorms are forecast for the Central Highlands on Wednesday afternoon and evening, with rainfall of 10-30 mm and more than 50 mm in some areas. Thunderstorms could bring lightning, hail and strong winds.
Saudel initially formed over the northwestern Pacific on August 9. After passing north of the Northern Mariana Islands and across islands in southern Japan, it made landfall in China's Fujian Province on August 28.
The system later moved southeast towards Guangdong, weakening into a tropical depression and then a low-pressure area.
The low-pressure system entered the northern East Sea on August 31, strengthened into a tropical depression and regained storm strength early on September 1.