Forecasters warned that northern Vietnam is likely to experience more days of severe weather, including heavy rain, thunderstorms, lightning and hail.

Torrential rain causes localized flooding

According to the National Center for Hydro-Meteorological Forecasting, on May 17, scattered showers and thunderstorms affected the northeastern region, areas stretching from Hue to Lam Dong, and southern Vietnam, with some locations experiencing extremely heavy rainfall that triggered localized flooding.

Intense rainfall concentrated during the morning and early afternoon pushed precipitation levels sharply higher between 7am and 3pm.

Hong Ha in Quang Ninh recorded 220mm of rainfall, while Thuy Nguyen in Hai Phong received 160.4mm.

Tien Hung in Hung Yen measured 145.2mm, and Cam Nhan in Lao Cai recorded 89.2mm.

Authorities said heavy rain caused widespread flooding in central areas of Quang Ninh and Hai Phong, with water entering residential homes.

Forecasters said scattered showers and thunderstorms would continue across the northwestern region on Sunday evening and overnight, bringing rainfall of 15-30mm, with isolated areas expected to exceed 90mm.

The northeastern region is forecast to see moderate to heavy rain and scattered thunderstorms, with rainfall ranging from 20-40mm and isolated areas surpassing 100mm.

Meanwhile, Thanh Hoa through Hue and the south-central coastal region are also expected to experience scattered showers and thunderstorms, with some areas receiving more than 90mm of rain.

The Central Highlands and southern Vietnam are forecast to continue seeing scattered thunderstorms with rainfall between 10-30mm, while isolated locations could record more than 90mm.

Meteorologists warned residents to remain alert for tornadoes, lightning, hail and strong winds accompanying thunderstorms.

Thunderstorms expected nationwide

Weather experts said the unstable conditions are being driven by a low-pressure trough stretching northwest to southeast across northern Vietnam and the central East Sea.

Over the next two days, thunderstorms are expected to persist nationwide.

The northeastern region is forecast to maintain widespread rain and scattered thunderstorms, with isolated areas facing torrential downpours.

The northwestern region is also expected to experience scattered showers and thunderstorms, with localized heavy rain.

In central Vietnam, coastal provinces are likely to see isolated rainfall during the day, while showers and thunderstorms are expected to intensify during the late afternoon and evening.

The Central Highlands and southern Vietnam are also forecast to continue experiencing scattered thunderstorms during the afternoon and night, with isolated heavy rain.

Heatwave expected after storms

Looking further ahead, meteorologists said widespread heat is likely to return to northern and central Vietnam from May 19 to May 27 once the current storm system weakens.

In northern Vietnam, moderate to heavy rain and thunderstorms are forecast to continue from May 19 to May 21, with some areas likely to see extremely heavy rainfall.

Rainfall is expected to gradually decrease on May 22, although isolated heavy downpours may still occur.

Forecasters noted that from May 23, widespread heat is highly likely to return across northern Vietnam, including Hanoi.

During the same period, Thanh Hoa to Da Nang and eastern areas from Quang Ngai to Dak Lak are forecast to experience scattered afternoon and evening thunderstorms between May 18 and May 20.

Localized heat is expected to develop again from around May 21, before expanding into a broader heatwave from May 22 to May 23.

Southern Vietnam and other regions are expected to continue seeing scattered showers and thunderstorms, especially during the late afternoon and evening, with isolated heavy rainfall.

Meteorologists warned that intense rainfall occurring within short periods could trigger urban flooding and landslides in mountainous areas.

Residents were also advised to avoid outdoor activities during severe thunderstorms, as lightning, hail and strong winds could pose serious risks to life and property.

Bao Anh