Prolonged heavy rainfall lasting up to six days due to Storm Fengshen is expected to push river levels in central Vietnam above the third (highest) warning level, posing risks of flash floods and landslides.

According to the National Center for Hydro-Meteorological Forecasting (NCHMF), at 7 a.m. Monday the storm lay centered 490 km east-northeast of the Hoang Sa (Paracel) Islands, with maximum sustained winds of 88 kph and gusts up to 102 kph, moving northwest at 25 kph.

By Tuesday morning, the storm is forecast to be about 180 km from Hoang Sa, then gradually shift west-northwest and later southwest due to interaction with a cold air mass, moving at around 20 kph. At 4 a.m. Wednesday, the storm will be over the northwestern waters of Hoang Sa with winds of 89-117 kph, before continuing southwest at about 10 kph. By Thursday, it is expected to approach waters from Hue to Quang Ngai in central Vietnam, weakening to 61-74 kph.

The Japan Meteorological Agency reported Fengshen's current wind speed at 83 kph, predicting a peak of 108 kph on Tuesday before weakening near the Vietnamese coast. The Hong Kong Observatory issued a similar outlook, forecasting winds of about 75 kph as the storm nears waters between Da Nang and Quang Ngai.

While precise rainfall totals are not yet available, NCHMF warns that the storm's circulation -- combined with cold air, easterly disturbances, and terrain effects -- will likely bring persistent heavy rain from Oct. 22-27 across Ha Tinh to Quang Ngai, potentially leading to significant flooding. Authorities are urged to prepare for scenarios in which river levels in Quang Tri-Quang Ngai exceed the highest flood warning threshold, alongside elevated risks of flash floods and landslides.

On Sunday evening, the National Civil Defense Command issued an emergency dispatch to coastal provinces from Quang Ninh to Lam Dong, urging close monitoring of the storm, timely communication with vessels, and readiness for rescue and disaster response. Relevant ministries were also directed to coordinate with local authorities on preparedness measures.

So far this year, the East Sea, known internationally as the South China Sea, has recorded 12 storms and four tropical depressions; several -- including Wutip, Wipha, Kajiki, Nongfa, Ragasa, Bualoi, and Matmo -- have caused severe flooding and damage in northern and central Vietnam.

Natural disasters this year have left 241 people dead or missing and 389 injured, damaged 261,000 homes, and flooded 594,000 hectares of crops. About 30,800 livestock and 2.7 million poultry were lost, with total economic damage exceeding VND53.8 trillion (US$2.1 billion).