Hanoi, Oct. 3 -- Vietnam's northern and north-central regions will experience sunny weather, with hot conditions in some areas on October 3, before a cold spell arrives from the evening and night of October 4, according to the National Centre for Hydro-Meteorological Forecasting. The centre said a cold air mass is currently moving southward, while scattered showers and thunderstorms are occurring in parts of the northern region. The cold air is forecast to reach northeastern Vietnam from the evening and night of October 4 before spreading to other parts of the north and the area from Thanh Hoa to Hue. Winds will shift to the northeast at levels 2-3 inland and levels 3-4 along coastal areas. Northeastern Vietnam and Thanh Hoa are expected ...