Hanoi Forecast: Heavy Rain During Rush Hour, Potential for Local Flooding

Hanoi, Vietnam's capital, is forecast to experience heavy convective rainfall on the afternoon of September 15th, with concerns rising over localized flooding and traffic disruptions, particularly during the evening rush hour. This weather event is attributed to the combination of southeasterly winds following a tropical depression and a cold air mass, which has led to persistent heavy rain since the previous day. From 7 PM on September 14th to 1 PM today, rainfall measurements showed Thanh Oai district receiving 140 mm. Hong Son, Ung Hoa, and Van Dinh districts recorded approximately 130 mm. In the inner city areas, Xuan Dinh saw over 110 mm, while Lang, Dai Thanh, Tu Liem, and Thanh Tri districts all exceeded 100 mm. According to the National Center for Hydro-Meteorological Forecasting, as of 1:30 PM today, satellite imagery, lightning detection, and weather radar indicated that convective clouds were active and continuing to develop over several areas, including Chuong My, Hoang Mai, Kien Hung, Linh Nam, Phu Luong, Tuong Mai, Vinh Tuy, Yen So, Thanh Tri, Dai Thanh, Phu Dong, Viet Hung, Dong Anh, and Bo De. Over the next approximately three hours, showers and thunderstorms are expected to continue in these areas and may expand to include Soc Son, Noi Bai, Me Linh, Quang Minh, Tay Tuu, Xuan Phuong, Yen Nghia, An Khanh, Hoai Duc, Dan Phuong, Quoc Oai, Xuan Mai, Hoa Lac, Ba Vi, Tay Ho, and other localities. Localized rainfall could exceed 50 mm. The heavy rain during rush hour poses a risk of localized flooding, reduced visibility, and traffic impediments. Thunderstorms may also bring tornadoes, lightning, hail, and strong gusts. The heavy rainfall from last night has already significantly impacted Hanoi's traffic. Despite the rain subsiding around 9 AM on September 15th, major routes such as Nguyen Van Linh, Dam Quang Trung, Nguyen Trai, Thai Ha, and Truong Chinh experienced traffic jams stretching 2-3 km, with some areas seeing flooding and water accumulation. The meteorological agency forecasts heavy to very heavy rain for Hanoi on September 15th, with temperatures ranging from 23-27 degrees Celsius and winds from the northeast to east at level 2-3. Heavy rain is expected to persist in the northern and north-central regions on September 16th, after which the extent of heavy rainfall is likely to decrease. In mountainous areas, heavy rainfall could trigger flash floods in small rivers and landslides on steep slopes.