Houses were flooded, mainly in Ham Rong ward and the communes of Kim Tân, Nông Cống, and Hoạt Giang (Thanh Hoá Province). VNA/VNS Photo

HÀ NỘI — The National Centre for Hydro-Meteorological Forecasting has warned of flash floods, landslides and ground subsidence on slopes and along small streams in Sơn La, Phú Thọ, Lào Cai, Thái Nguyên, Quảng Ninh, Thanh Hóa and Nghệ An provinces within the next five hours, as widespread showers and thunderstorms sweep across the country throughout the day and night of September 18. Thunderstorms may bring tornadoes, lightning and strong gusts.

In Hà Nội, satellite imagery, lightning-location data and weather radar show convective clouds producing rainfall over the wards and communes of Hương Sơn and Mỹ Đức. Within the next two hours, the storm-cloud system is expected to bring showers and thunderstorms to Hương Sơn, Mỹ Đức, Hồng Sơn, Hoà Xá, Gia Lâm and Bát Tràng.

The capital is forecast to be mostly cloudy with occasional showers and thunderstorms, with minimum temperatures of 23-25 degrees Celsius and maximums of 27-29 degrees Celsius.

The forecasting centre has warned of heavy rainfall from Thanh Hóa to Huế. From early morning through the end of September 18, the area from Thanh Hóa to Hà Tĩnh will experience moderate to heavy rain and thunderstorms, with rainfall generally ranging from 20-50mm and locally exceeding 80mm.

From the night of September 18 through September 19, the area from Nghệ An to Huế will see moderate to heavy rain, with rainfall generally ranging from 30-60mm and locally exceeding 100mm. A warning has been issued for the risk of rainfall intensity exceeding 100mm over three hours. During the night of September 19 and on September 20, the area from Hà Tĩnh to Huế will experience moderate rain with rainfall of 20-40mm, and locally exceeding 80mm.

Elsewhere on September 18, the northern region will see scattered showers with rainfall of 10-30mm, and locally exceeding 50mm. During the afternoon and evening, the south will experience moderate rainfall and thunderstorms, with locally heavy rainfall of 20-40mm and exceeding 80mm in some areas. The Central Highlands, Khánh Hòa Province and eastern Lâm Đồng Province will see scattered showers of 10-30mm, locally exceeding 60mm. Thunderstorms may bring tornadoes, lightning, hail and strong gusts.

The Gulf of Tonkin, the waters from Lâm Đồng to Cà Mau, from Cà Mau to An Giang, the Gulf of Thailand, the northern East Sea including the Hoàng Sa special zone, and the southern East Sea including the Trường Sa special zone are all experiencing scattered showers and thunderstorms. The Phú Quý station has recorded wind gusts of force nine.

Forecasters predict the same sea areas will see scattered showers and thunderstorms throughout the day and night of September 18, with a high likelihood of waterspouts, strong gusts of force seven to eight and waves exceeding two metres. All vessels operating in these areas are at risk.

As of 5.30pm on September 17, floods and landslides had killed three people in Phú Thọ. Four houses had collapsed in Thanh Hóa, 29 houses had been damaged and 16,310 houses had been inundated. — VNS