According to the National Center for Hydro-Meteorological Forecasting, at 10:00 AM on August 24, the center of storm No. 4 was located at about 20.3 degrees North latitude - 107.6 degrees East longitude, in the northwest sea area of Bach Long Vi special zone, about 125km east-southeast of Quang Ninh and about 120km east of Hai Phong City.
The strongest wind near the storm center is strong at level 9, equivalent to 75-88km/h, gusting at level 11. The storm moves in the South - Southwest direction at a speed of about 5km/h.
Due to the impact of storm No. 4, strong winds of level 9, gusts of level 11 were recorded in Bach Long Vi special zone; Co To special zone had strong winds of level 6, gusts of level 9; Mong Cai level 7, gusts of level 9; Uong Bi level 6, gusts of level 7; Phu Lien level 7, gusts of level 8; Vu Ninh level 6, gusts of level 7 and Bai Chay level 6, gusts of level 7.
The storm's circulation also caused moderate to heavy rain, with very heavy rain in some places in the Northeast region, southern Phu Tho and Thanh Hoa provinces.
From 7 pm on August 21 to 10 am on August 24, common rainfall is 150-250mm. Especially in the Lang Son, Quang Ninh, Bac Ninh and Hai Phong city areas, there will be heavy to very heavy rain, common rainfall is 180-380mm, locally over 400mm.
Some places recorded very heavy rainfall such as Hong Ha (Quang Ninh) 550mm, Mau Son (Lang Son) 544mm, Cat Ba (Hai Phong City) 414mm.
Forecast for the next 24 hours, storm No. 4 will continue to move slowly in the South - Southeast direction at a speed of about 5km/h. By 10:00 AM on August 25th, the storm's center is likely to be at about 19.9 degrees North latitude - 108.5 degrees East longitude, over the eastern Gulf of Tonkin, about 10km east - Southeast of Bach Long Vi special zone.
At this time, the storm still maintains intensity of level 9, gusts of level 11. The dangerous area is determined to be north of latitude 18.5 degrees North latitude, in the range from 106.5-110.0 degrees East longitude.
Disaster risk level 3 is warned in the Gulf of Tonkin, including Bach Long Vi, Van Don, Co To, Cat Hai special zones and Hon Dau island; coastal mainland and coastal sea areas of Quang Ninh, Hai Phong City and Hung Yen.
By 10:00 AM on August 26, the storm is likely to turn north-northeast, moving at a speed of about 5km/h. The storm's center is forecast to be at about 21.3 degrees North latitude - 109.5 degrees East longitude, over the northeastern sea area of the Northern Gulf of Tonkin, about 240km northeast of Bach Long Vi special zone.
The storm intensity at this time gradually weakens, reaching level 8, gusting to level 10. Natural disaster risk level 3 continues to be maintained for the Gulf of Tonkin area, including Bach Long Vi special zone.
By 10:00 AM on August 27, the storm will weaken into a tropical depression when it is about 22.7 degrees North latitude - 109.5 degrees East longitude, on land in the southern province of Guangxi (China). This system is likely to reach level 6, gusting at level 8 and continue to move north at a speed of 5-10km/h.
From the next 72-96 hours, the tropical depression is likely to turn northwest, traveling 5-10km per hour and gradually weakening into a low pressure area on land in the south of Guangxi province (China).
At sea, the area affected by the storm includes the Gulf of Tonkin, Bach Long Vi, Van Don, Co To, Cat Hai special zones, Hon Dau island, Quang Ninh coastal sea area, Hai Phong city and Hung Yen.
Sea winds can be strong at level 6-7, waves 2-3m high. The area near the storm center passing through has strong winds at level 8-9, gusts at level 10-11, waves 3-5m high, very rough seas.
For coastal land in Quang Ninh, Hai Phong City and Hung Yen, the wind may be strong at level 6, gusting at level 8. Strong winds are at risk of blowing roofs, damaging temporary structures, breaking and collapsing green trees, billboards, and affecting electricity and traffic systems.
Heavy rain continues to be one of the noteworthy risks due to the circulation of storm No. 4. From noon to evening on August 24, Hai Phong City, Hung Yen, Ninh Binh, southern Phu Tho province and the area from Thanh Hoa to Ha Tinh will have heavy to very heavy rain, common rainfall of 40-70mm, locally over 140mm.
From the night of August 24 to the morning of August 25, the coastal areas of the Northern region, Thanh Hoa and Nghe An will continue to have moderate rain, heavy rain and thunderstorms, common rainfall of 20-50mm, locally over 100mm.
Heavy rain may cause flooding in urban areas, industrial parks and low-lying areas; and at the same time increase the risk of floods on small rivers and streams, flash floods and landslides in mountainous areas.
People and tourists in coastal localities of Quang Ninh, Hai Phong, Hung Yen need to proactively take safety measures. Mountainous areas and low-lying areas need to closely monitor the diễn biến of heavy rain, the risk of flash floods, landslides and flooding to proactively respond.
