Residents in Hanoi wade through floodwaters on Thuy Khue Street after a heavy downpour on July 27, 2026. Photo: C. Tue / Tuoi Tre News

Pham Thi Cham, a forecaster at the National Center for Hydro-Meteorological Forecasting, said weather radar on Monday afternoon showed that thunderstorms had already developed across several northern provinces and cities.

Rainfall in northern mountainous and midland provinces is expected to reach 70-120 mm, with some locations exceeding 250 mm through Tuesday night.

These provinces have experienced repeated heavy rainfall in recent weeks, leaving soil saturated and unstable.

Additional downpours could significantly increase the risk of flash floods and landslides.

Residents should remain on high alert.

Hanoi and other lowland areas may see lighter rainfall, ranging from 50-100 mm, with localized totals above 150 mm.

In the Central Highlands and southern provinces, rainfall is forecast at 40-100 mm, with some places receiving more than 200 mm until Wednesday.

The forecaster warned that thunderstorms could bring whirlwinds, lightning, hail, and strong gusts.

On Monday, the National Civil Defense Steering Committee issued a directive urging provinces in the Central Highlands and southern regions to closely monitor weather updates, inform local authorities and residents promptly, and evacuate people from high-risk areas.