Typhoon Koppu made landfall in the early hours of Sunday (local time) close to Casiguran in northern Philippines as an intense Typhoon. At landfall it was equivalent to a category 4 Hurricane with sustained winds averaged over a minute estimated to be close to 155 mph with gusts near 185 mph. There were reports of significant storm surge/large waves.
Through Sunday Koppu tracked slowly west across Luzon and was near San Fernando this morning (Monday) where it was downgraded to a Tropical Storm. It is expected to continue slowly across the north of Luzon through Monday and much of Tuesday.
Rainfall and flooding are now the main threat with torrential rain forecast in areas over the next 48 hours. 238mm was recorded in the city of Baguio in just 6 hours earlier today. Total rainfall from Saturday to Tuesday could be as high as 1500mm in places. Several dams are at risk of overflowing and there is a significant landslide risk in the coming days.
There is considerable uncertainty in the track of Koppu as it clears the Philippines later this week. Some models take this system north, perhaps strengthening into a typhoon again and producing a risk of flood impacts in parts of Taiwan. However, it is possible Koppu could move north-east avoiding any impact on Taiwan, but posing a threat to the Ryukyu Islands of Japan.