Residents of the northern Philippine island of Luzon are preparing for the arrival of a potent storm this weekend.
Tropical storm Koppu was lying 1,200km to the east of Manila at 00:00GMT on Thursday.
Koppu is expected to intensify as it gains energy from the exceptionally warm waters of the equatorial Pacific Ocean.
Sustained winds are expected to reach 205km/h while it remains over open water. This is the equivalent of a Category 3 storm on the five point Saffir-Simpson scale.
Koppu may even attain category 4 status if it was to strengthen by just another 5km/h.
There is expected to be some weakening of the typhoon before it makes landfall. This is expected to be late on Sunday, although recent computer forecasts have suggested a significant slowing of Koppu’s eastward movement.
Landfall is expected to be made along the coast adjacent to Ilagan City.
A Category 3 equivalent typhoon typically produces winds likely to cause ‘extreme damage’. Large trees may be blown down and some structural damage is likely.
Rainfall may be the most dangerous and disruptive element of Koppu.
The storm is expected to slow to such an extent that rain is likely to fall for up to 24 hours.
Accumulations well in excess of 500mm could occur over quite a large area, with the mountains seeing up to 900mm. Flash flooding and mudslides are highly likely.
Koppu’s current forecast track would mean that Manila would miss the worst of the weather.
On clearing Luzon, Koppu will head into the East China Sea, weakening as it passes over cooler waters and experiences increased wind shear (a change of wind speed and direction with height) which will disrupt its circulation.
Nevertheless, it is possible that Koppu could bring flooding rain to eastern China and Taiwan later next week.