The Central Hydrometeorological Station issued a bulletin on November 16, saying that the strong cold air mass will continue to move south and will affect Da Nang from the night of November 17. The northeast wind inland reaches level 3, coastal areas level 3-4, gusting to level 5-6.
From November 18, Da Nang will turn cold, with some places experiencing cold, with the lowest temperature commonly 19-21°C, mountainous areas 17-19°C. At sea, Hoang Sa special zone and Da Nang sea area have strong winds of level 6-7, gusts of level 8-9, waves 2-4m high.
From November 16, Da Nang area will experience moderate to heavy rain due to cold air combined with high-altitude easterly wind disturbances. Rainfall from the night of November 15 to November 17 in the plains and midlands is generally 150250mm, in some places over 300mm.
From the night of November 17 to the end of November 18, heavy rain will continue, with a total of 80200mm, the area may exceed 300mm.
The risk of flash floods, landslides in mountainous areas and deep flooding in low-lying areas is warned at a high level. The plains and northwestern mountainous areas are at level 1 natural disaster risk; the southern mountainous areas are at level 2. Shipping, agricultural production and infrastructure activities may be affected by strong winds, large waves and thunderstorms.
Due to the complicated developments of floods and forecast of very heavy rain lasting until November 19, hydroelectric reservoirs in Da Nang have been required to simultaneously operate and release water to ensure safety for downstream.
According to Song Bung Hydropower Company, Song Bung 4 Lake started regulating from 1:00 a.m. on November 16, with a discharge flow of 150 - 1,500 m3/s. The goal is to lower the water level to 216m elevation before 9:00 a.m. on November 17, to increase the ability to cut flooded areas downstream. At the same time, A Vuong Hydropower Joint Stock Company also operated discharge with a flow rate of 70 - 350m3/s. The unit said that the lake needs to bring the water level to the lowest flood level of 370m before 9:00 a.m. on November 17 to cope with heavy rain for many consecutive days.
Song Tranh Hydropower Plant announced that Song Tranh 2 Lake is operating at a regulated flow rate of 220 - 1,500m3/s to lower the water level to the flood reception level according to regulations. Data at 10:00 on November 16 showed that the lakes increased their flow downstream to proactively prevent floods.
Localities are required to closely monitor developments, proactively respond and ensure safety for people in the context of prolonged floods.
