According to the National Center for Hydro-Meteorological Forecasting, scattered showers and thunderstorms affected the northern mountainous region on the night of June 6, with some locations recording heavy rainfall. Rainfall measured between 7 p.m. on June 6 and 7 a.m. on June 7 exceeded 30mm at several monitoring stations, including 31.8mm in Ban Giang (Lai Chau), 94mm in Tan Lap 1 (Tuyen Quang), and as much as 132.6mm in Tan Lap 2 (Tuyen Quang).

Forecasters expect scattered showers and thunderstorms to continue across the northern mountainous provinces on the evening and night of June 7, with rainfall ranging from 10-20mm and isolated areas receiving more than 50mm. Thunderstorms may be accompanied by tornadoes, lightning, hail and strong gusty winds.

However, the more significant rain event is forecast to begin on the evening of June 8. Under the influence of a late-season cold air mass, northern Vietnam, Thanh Hoa and Nghe An provinces are expected to experience moderate to heavy rain from the evening of June 8 through June 9.

The northwestern region, along with northern parts of Phu Tho and Tuyen Quang provinces, is forecast to receive heavy to very heavy rain accompanied by thunderstorms, with rainfall totals ranging from 50-100mm and isolated areas exceeding 200mm.

Elsewhere across northern Vietnam as well as Thanh Hoa and Nghe An, widespread moderate to heavy rain and thunderstorms are expected, with rainfall generally between 20-50mm and some locations receiving more than 100mm.

Extreme rainfall warning raises flood and landslide concerns

Meteorologists have warned that some areas could experience extremely intense rainfall exceeding 100mm within just three hours. Such conditions significantly increase the risk of flash floods on small rivers and streams, landslides in mountainous areas, and localized flooding in low-lying and urban areas.

Rainfall is expected to persist across the northwestern region and the north-central provinces on June 9, with totals generally ranging from 30-60mm and isolated locations receiving more than 100mm.

Looking further ahead, forecasters said the northwestern region is likely to continue experiencing scattered showers and thunderstorms, with isolated heavy rainfall lasting through around June 12. From approximately June 13 onward, northern Vietnam is expected to see scattered showers and thunderstorms, with some areas continuing to receive heavy rain.

The north-central region is also forecast to experience scattered thunderstorms and localized heavy rain through June 11. From around June 12-13, isolated heatwave conditions could return.

Residents in mountainous areas are advised to closely monitor weather developments and remain alert to dangerous thunderstorm-related phenomena, as well as the heightened risks of flash floods, landslides and flooding caused by prolonged heavy rainfall.

Bao Anh