PORT VILA – Tropical cyclone Pam has been upgraded to a category four storm as it heads towards Vanuatu.

Evacuation plans are being made and ships have been confined to port as Vanuatu waits for what is likely to become the most devastating cyclone since Cyclone Uma in 1987.

The Vanuatu Meteorological Service is briefing the public on the hour on the increasing strength of the cyclone.

It had warned of “severe and damaging” winds in Port Vila on the Island of Efate and the southern part of Vanuatu.

The National Disaster Management Office (NDMO) in Vanuatu is scrambling to organise evacuation centres.

The acting director of the meteorological department in Vanuatu says Cyclone Pam has the potential to become the strongest storm ever experienced in the country.

David Gibson says Port Vila on the Island of Efate and the Southern part of Vanuatu are expected to face severe and damaging winds on Friday afternoon.

Gibson says the category three cyclone is expected to intensify. “Based on the forecast the intensity will reach Category 5. That’s the forecast. This is the first time that Vanuatu would experience such a cyclone if it reaches category five. In 1987 Tropical Cyclone Uma was category three and then four as it moved.”

NDMO acting director Peter Korisa said the main worry is how to give refuge to the more than 45,000 people of Port Vila.

Korisa said new settlements around Port Vila are at risk and officials are working on an evacuation plan.

“There’s no formal standard house here so I’m just imagining if this happens in Port Vila, it will be disastrous.

“What we are doing we’re trying to arrange the evacuation centres. We’re talking with civil authorities, especially church organisations, schools and public buildings. We’re trying to arrange if we can use these evacuation centres.”

If the damage caused by Tropical Cyclone Pam was beyond the capacity of Vanuatu government, it would appeal to international donors, he said.

In March last year, Vanuatu was hit by Cyclone Lusi over two days, killing 10 people, damaging crops and infrastructure, flooding towns and contaminating the water supply.

Alice Clements from UNICEF’s Pacific office arrived in Vanuatu on Wednesday and says due to its geography, the entire country is vulnerable.

“There’s preparations at the government level, at institutional levels, and then of course with communities and children who are always worse affected by these types of disasters. There’s government appointed shelters for people who are living in low income housing areas who are very vulnerable as well.”

Alice Clements says the cyclone has the potential to inflict quite a lot of damage over a period of days.

The Vanuatu Meteorological Services predicted gale-force winds for the southern part of Vanuatu including Port Vila would start from 11pm (local time) on Wednesday night.

The service said winds near the centre of the cyclone were estimated at 165 kilometres per hour.

Senior forecaster for the service, Allan Ravai, said winds of up to 90 kilometres per hour were expected within the next 24 hours as the system moved south at a speed of 10 kilometres per hour.

“We still advise people of the damaging winds and very rough seas with heavy swells, mainly for the northern provinces.”

He said heavy rain and flooding was also expected in Vanuatu’s north, including coastal flooding.

Ravai said the cyclone is predicted to become a category five system on Friday when it is 120 kilometres east of the country’s central island.

Australian Bureau of Meteorology national operations centre head Andrew Tupper said Pacific nations were on high alert.

“This is actually the most significant cyclone of all in terms of its size, which is very large, and its intensity,” Tupper said.

“It’s forecast to thread the needle between Vanuatu and Fiji as it moves south, but probably a little bit too close to Vanuatu for anybody’s liking.”

A heavy rain and gale wind warning is also in place for Fiji. Shipping vessels have been ordered to stay in port, while residents in Fiji have been urged not to head out to sea this week.

Residents in the eastern parts of Solomon Islands have also been told to expect heavy rain, gale-force winds and high seas.

Meanwhile, Queensland coastal communities are preparing for Cyclone Nathan which is located off the state’s far north coast.

Although close, the two systems are not expected to merge.