On the afternoon of October 20, Pham Thi Thanh Hoa, a forecaster at the National Center for Hydro-Meteorological Forecasting, provided an update on the approaching cold air mass and its expected impact on weather conditions across Vietnam.

According to Hoa, northern Vietnam and provinces from Thanh Hoa to Hue will continue to experience sunny conditions during the day on October 20, with isolated showers possible in the late afternoon and at night.

Meanwhile, areas from Da Nang to Lam Dong and southern Vietnam will see mostly cloudy skies, scattered rain and locally heavy downpours.

A weak surge of cold air is forecast to move into Vietnam from October 21.

However, because the cold front is relatively weak and its movement is oriented toward the east, it is expected mainly to trigger scattered showers and a slight decline in temperatures rather than a noticeable spell of cold weather.

Specifically, on October 21-22, northeastern Vietnam and areas from Thanh Hoa to Hue are forecast to experience scattered showers and isolated thunderstorms.

The rainfall will result from the combined effects of the weak cold air mass and easterly to southeasterly winds at altitudes of approximately 1,500-5,000 metres.

However, rainfall totals are expected to remain relatively low, with precipitation affecting limited areas.

As a result, temperatures in these regions are likely to fall by only 1-2°C.

After October 22, rainfall is expected to decrease, while temperatures will gradually rise again toward the weekend.

The approaching cold front is therefore unlikely to bring an end to the prolonged spell of sunny weather across northern Vietnam.

At sea, northeasterly winds over the northeastern waters of the northern East Sea are forecast to strengthen to force 6 on the Beaufort scale from the afternoon of October 21, with gusts reaching force 7-8.

Waves could reach heights of 2-4 metres, creating rough seas and hazardous conditions for fishing vessels and other maritime activities.

Southern Vietnam and Lam Dong to see further evening thunderstorms

In areas stretching from Da Nang to Lam Dong and across southern Vietnam, disturbances in the easterly wind flow are weakening but could still produce scattered showers and thunderstorms on October 21-22.

Lam Dong and southern provinces, in particular, may experience locally heavy rainfall during the late afternoon and evening.

Meteorological authorities have warned that thunderstorms could be accompanied by whirlwinds, lightning and strong wind gusts.

Intense rainfall over short periods could also cause localised flooding in low-lying areas.

From October 23, weather conditions across these regions are expected to improve gradually.

Rainfall should decrease rapidly, with only isolated showers remaining.

Bao Anh