Starting Sunday, temperatures across northern regions and Thanh Hoa will drop by up to five degrees Celsius from Saturday, down to around 19-21 degrees and even 18 degrees in mountainous areas, according to the National Center for Hydro-Meteorological Forecasting.

The currents of the ongoing Lionrock storm, combined with low temperatures, will send downpours to northern Vietnam from Sunday to Tuesday. Rain levels in northeastern regions would be around 150-300 millimeters per session; 50-150 millimeters for northwestern regions. Localities like Thanh Hoa, Nghe An and Ha Tinh will experience rain levels between 100-250 millimeters per session, according to the center.

In Hanoi, heavy rains will be observed from Saturday afternoon to Monday. Starting Sunday, temperatures in the capital will drop to around 20-21 degrees Celsius.

As of 1 p.m. Saturday, the Lionrock storm was above Hainan Island with a maximum wind speed of 75 kph. Within the next 24 hours, it is forecast to move west-northwest at around 10 kph and enter the Gulf of Tonkin.

Within the next 36 hours, the storm may switch direction to west-southwest, moving at 15-20 kph and devolve into a tropical depression, making landfall in northern-north central Vietnam.

Due to impacts of the storm and cold air, heavy rains would be observed from Saturday to Tuesday in northern and north central localities, up to 300 millimeters per session.