The tropical storm has triggered drenching rainfall of up to 250 mm last night in the mainland provinces from Thanh Hoa to Quang Binh.
At 5 a.m. on Sunday, the eye of Koguma was located in the coastal mainland provinces from Thai Binh to Nghe An with a maximum wind of 75 kilometers an hour.
By this noon, the storm will move west northwestwards at a speed of 20 kilometers an hour and dowgrade into a tropical depression in the mainland of Thanh Hoa Province.
Koguma is forecast to continue bringing heavy rains and strong winds in the Red River Delta, the Northern midland region and provinces from Thanh Hoa to Ha Tinh. It will cause rain surges, rough sea, big waves, cyclones and whirlwinds in Bach Long Vi Island, the northern and southern territorial waters including the Spratly Islands, the coastal provinces from Binh Thuan to Kien Giang and the Gulf of Thailand on Sunday.
Downpour surge is expected to trigger floods in rivers and streams of the provinces from Thanh Hoa to Quang Binh from June 12 to 16.