Tropical Cyclone Amos is starting to show its fierce hand over Samoa, with reports of flash flooding, trees down and mass power outages.

The brunt of the storm - expected to become a category 4-strong cyclone - is forecast to hit the island nation in the early hours of this morning.

Samoa's Disaster Management Office is sending out warnings to locals via its social media pages, as strong winds and heavy rain have started to bring down power lines. There has been flash-flooding in parts of the big island of Savaii, where authorities say a bridge in Salei'a, on the northern coast, has been washed away - preventing access to and from neighbouring villages.

That area is particularly popular with tourists as there are a number of well-known resorts and accommodation sites on that stretch of road.


Samoan Police issued a warning late on Saturday night that downtown Apia was now flooded and the public were urged to stay indoors as the roads were unsafe for travelling.

Just before 8pm today, former Aucklander Seti Afoa told the Herald weather conditions in the capital, Apia, were calm and there was no wind or rain.

Just before midnight tonight, Mr Afoa said things had changed dramatically over the last few hours.

"Massively [changed]. Big rain now and strong wind. All power is out around Apia and Savaii...Apia is getting what Savaii got six hours ago.''

Mr Afoa is manning a local radio station overnight, in a bid to keep locals informed. He said they were running on a generator now.

Authorities have warned locals to refrain from travelling on various roads where fallen trees and power lines were now blocking access. It was not yet safe for authorities to head out to remove the debris, so locals were being told to stay inside.

Cyclone Amos is also tracking towards American Samoa; where locals there are also preparing for the worst over the next few day or two.

Meanwhile, Samoans have started to use the hashtag #TCAmosWatch on social media in a bid to keep friends and families both in the motherland and overseas updated.