According to the National Centre for Hydro-Meteorological Forecasting, a cold air mass combined with an upper-level westerly trough will bring rain, scattered thunderstorms and locally heavy downpours to northern Vietnam.
Temperatures across the region are expected to remain low, generally ranging from 14 to 17 degrees Celsius, with some high-altitude areas falling below 13 degrees Celsius.
Daytime highs will range from 19 to 23 degrees Celsius.
In Hanoi, cloudy skies are forecast with occasional showers and thunderstorms. Northeasterly winds will reach force 2-3, with temperatures ranging from 16-18 degrees Celsius overnight to 20-22 degrees Celsius during the day.
Rain and thunderstorms are expected to continue into November 14, with some areas in the northeast facing heavy to very heavy rainfall.
From the evening of November 13 to the morning of November 14, northeastern provinces are forecast to receive 20-40mm of rain, with isolated areas exceeding 80mm.
Northwestern provinces are expected to see scattered showers and thunderstorms, with rainfall of 15-30mm and more than 60mm in some locations.
Meanwhile, heavy rain in central Vietnam is forecast to gradually ease from the afternoon of November 13.
Forecasters warned that downpours could still cause flooding in low-lying areas, urban centres and industrial parks, while mountainous areas face risks of flash floods in small rivers and streams and landslides on steep slopes.
In southern Vietnam, partly cloudy conditions are expected, with isolated daytime showers and thunderstorms becoming more widespread in the late afternoon and evening. Some areas could experience heavy rain.
Daytime temperatures in the south are forecast to reach 30-33 degrees Celsius.
Residents have been advised to remain alert to whirlwinds, lightning and strong gusts during thunderstorms.
