Tropical Cyclone Amos strengthened as it passed over Iles Wallis and headed toward Samoa on Friday. At 5:00 p.m. EDT on Friday the center of Tropical Cyclone Amos was located at latitude 12.5°S and longitude 175.4°E which put it about 70 miles (115 km) north-northeast of Iles Wallis and about 360 miles (580 km) west-northwest of Pago Pago, Samoa. Amos was moving toward the east at 11 m.p.h. (18 km/h). The maximum sustained wind speed was 105 m.p.h. (170 km/h) and there were wind gusts to 125 m.p.h. (205 km/h). The minimum surface pressure was 956 mb.
The core of the circulation of Tropical Cyclone Amos is small but it is well organized. There is a ring of the thunderstorms around an eye, but clouds from the taller thunderstorms are obscuring the eye on conventional satellite imagery. Multiple bands of thunderstorms are rotating around the core of the circulation. The thunderstorms are generating well developed upper level divergence which is pumping out mass in all directions.
Tropical Cyclone Amos is an environment favorable for further intensification. It is moving over water where the Sea Surface Temperature is near 30°C. The winds in the upper levels are weak and there is not much vertical wind shear. Amos is likely to intensify during the next 24 hours and it could be the equivalent of a major hurricane when it reaches the western part of Samoa.
A ridge of high pressure is expected to steer Tropical Cyclone Amos toward the east-southeast during the nest several days. On its anticipated track Amos could be approaching the western islands of Samoa in a little over 24 hours. It could be the equivalent of a major hurricane at that time.
The Hurricane Intensity Index (HII) for Amos is currently 17.8. The Hurricane Size Index (HSI) is 9.0 and the Hurricane Wind Intensity Size Index (HWISI) is 26.8. Those indices suggest that the core of Tropical Cyclone Amos will be capable of causing major damage if it moves directly over any of the islands of Samoa. In addition, Amos will produce locally heavy rain capable of causing flash floods. It could also generate high waves and surges along the coasts of some of the islands.