The Southern Regional Hydro-Meteorological Centre forecasts the year's highest tides from October 27 to 29, following the full moon of the ninth lunar month.
At Phu An Station, water levels are forecast to reach 1.70-1.75 metres, 10-15 cm above Warning Level 3. At Thu Dau Mot Station, they are expected to reach 1.82-1.87 metres, exceeding the same warning level by 22-27 cm.
The centre also warned of thunderstorms in HCM City during the first 10 days of October, accompanied by possible whirlwinds, lightning and strong winds.
Localised heavy rain could cause flooding in poorly drained urban areas and trigger flooding or landslides along rivers and in low-lying areas.
City authorities have instructed departments and local administrations to prepare for heavy rain, high tides and possible flood discharges during the remainder of the rainy and storm season.
Officials have been told to monitor vulnerable areas, control traffic and prevent people and vehicles from entering deeply flooded or landslide-prone areas where conditions are unsafe.
Local authorities have also been asked to review areas at risk of severe flooding and landslides and evacuate residents when necessary.
Relevant agencies have been instructed to ensure drainage systems remain clear and protect dykes, reservoirs and flood-control infrastructure while preparing personnel and equipment for evacuation and rescue operations.
The city has also ordered warning signs, barriers and lighting to be installed at flooded roads, tunnels and other hazardous locations. Crews and equipment are to be kept ready to deal with incidents and maintain traffic on major routes.
Authorities have also been asked to inspect and trim trees to reduce the risk of them falling during thunderstorms and heavy rain.