People clean up mud after Wednesday’s flood, which inundated more than 1,000 houses in Đạ Huoai 3 Commune (Lâm Đồng) and swept away five others. — VNA/VNS Photo

HÀ NỘI — The National Centre for Hydro-Meteorological Forecasting has issued warnings of widespread heavy rain, thunderstorms and dangerous weather patterns from Friday to Saturday, raising the risk of flash floods and landslides in multiple provinces and cities.

From Friday evening to Saturday night, the northeastern region, Thanh Hóa and Nghệ An are forecast to see moderate to heavy rain and thunderstorms, with common rainfall of 60–130mm and some places exceeding 250mm.

The Central Highlands and southern regions are also expected to have 50–100mm of rain, with some locations topping 200mm.

Earlier, from Thursday night to early Friday morning, many northern, north-central and Central Highlands localities recorded substantial rainfall, including Khuôn Hà in Tuyên Quang (115.4mm), Lãng Ngâm in Bắc Ninh (103.2mm), Hiền Trung in Thanh Hóa (98mm) and Nghiên Loan in Thái Nguyên (95.8mm).

Satellite imagery, lightning location data and weather radar have detected convective clouds forming over parts of Hà Nội, including Yên Xuân, Tùng Thiện, Đoài Phương, Quảng Oai, Minh Châu and Ba Vì. 

These clouds are expected to continue producing rain on Friday before spreading to other wards. Thunderstorms may bring tornadoes, lightning and strong gusts. The disaster risk level for tornadoes, lightning and hail is rated at Level 1.

The agency warns of potential flash floods on small rivers and streams and landslides on slopes in many communes and wards across 13 provinces, including Lai Châu, Điện Biên, Sơn La, Phú Thọ, Lào Cai, Tuyên Quang, Thái Nguyên, Cao Bằng and Lạng Sơn.

Many of these areas have already seen significant rain on Friday, with some recording over 90mm in just a few hours. Soil moisture models indicate that in several locations, saturation levels have reached or exceeded 85 per cent, further increasing the risk of slope failure.

The Centre notes that flash floods and landslides can cause severe environmental damage, endanger lives, disrupt local traffic, destroy infrastructure and harm livelihoods. Local authorities are urged to inspect water flow bottlenecks and vulnerable areas, and take preventive and response measures.

Currently, southwest winds at force 5–6 (29-49km/h) on the Beaufort scale, with gusts up to force 8 (62-74km/h), are affecting waters around Phú Quý Island and the western part of the southern East Sea (internationally know as the South China Sea).

On Friday night, waters from Khánh Hòa to HCM City and the western southern East Sea are expected to face winds at force 6, with gusts force 7–8. Waves of 1.5–3m and rough seas are expected.

Similar conditions are forecast in the eastern southern East Sea and the northern East Sea, with waves of 1.5–3m, and in the eastern to southeastern central East Sea, with waves of 1–2.5m.

Additionally, the Gulf of Tonkin, waters from southern Quảng Trị to Cà Mau, from Cà Mau to An Giang, the Gulf of Thailand and most of the East Sea will have scattered showers and thunderstorms, with possible waterspouts, strong gusts and waves 2–3m high.

The disaster risk level from strong winds at sea for waters from Khánh Hòa to HCM City is Level 2. Mariners operating in these areas are warned of a high risk from waterspouts, strong winds and large waves.

Regional Weather Forecast for Friday:

• Northwest: Scattered showers and thunderstorms during the day; moderate to heavy rain at night. Tornadoes, lightning, hail and strong winds possible. Low 23–25°C; High 29–32°C.

• Northeast and Thanh Hóa: Rain, locally heavy; evening and night with moderate to heavy rain and thunderstorms, some very heavy. Low 23–26°C; High 28–31°C, some above 31°C.

• Nghệ An to Huế: Isolated showers during the day; scattered showers in the afternoon and evening; Nghệ An with moderate to heavy rain and thunderstorms. Low 24–27°C; High 30–33°C, some above 33°C.

• South Central Coast: Isolated showers in the day; scattered showers and thunderstorms in the afternoon and evening, locally heavy. Southwest winds force 2–3. Low 24–27°C; High 31–34°C, some above 34°C.

• Central Highlands: Scattered showers during the day; moderate to heavy rain in the afternoon and night. Low 19–22°C; High 27–30°C, some above 30°C.

• Southern region: Scattered showers in the day; moderate to heavy rain in the afternoon and night. Low 23–26°C; High 29–32°C, some above 32°C.

• Hà Nội: Moderate to heavy rain and thunderstorms, locally very heavy, mainly in the morning, late afternoon and night. Low 23–25°C; High 29–31°C.

• HCM City: Occasional showers during the day; moderate to heavy rain in the afternoon and night. Southwest winds force 2–3. Low 24–26°C; High 31–33°C. — VNS