GITA'S FURY
Wild winds fell trees and force water into homes as tropical cyclone hits the tiny island nation
Fierce winds struck Tonga last night, felling trees, ripping off roofs and driving rain into homes as Tropical Cyclone Gita hammered the tiny island nation.
Aid agencies warned coastal properties would be destroyed and people's livelihoods wiped out by what was feared to be Tonga’s worst storm.
Locals queued for supplies before boarding up windows then fleeing to makeshift evacuation centres as the wild weather bore down.
Forecasting models predict the cyclone will track towards New Zealand, arriving early next week.
Tonga’s residents were last night hunkering down as Cyclone Gita hit the tiny island nation in what was feared to be the fiercest storm in its recorded history.
Scared locals queued for supplies before boarding up windows and fleeing to makeshift evacuation centres as Gita bore down.
Fierce winds struck the country last night, felling trees and forcing water beneath residents’ doors as the Category 4 storm hit. Power was shut off to the main island of Tongatapu and 275km/h gusts reportedly blew the roof off the Met Office near the airport but the worst winds and damaging storm surges were expected overnight.
Acting Tongan Prime Minister Semisi Sika declared a state of emergency hours before Gita was due to hit, as forecasts predicted the storm could grow.
Aid agencies warned coastal properties would be destroyed and livelihoods wiped out by the winds.
Police imposed a curfew from 9pm last night to 7am today in the central business district of the capital, Nuku’alofa, which is on Tongatapu.
Most weather forecasting models predict the giant storm will track towards New Zealand and move across central parts of the country early next week.
As the cyclone bore down last night, Nuku’alofa resident Viliami Latu said the winds were getting stronger and stronger. Power had been shut off on Tongatapu, plunging everything into darkness.
He said at 10pm, with hours still to go until peak intensity, he and his family were bracing for what could be devastation.
Frederica Filipe said on Twitter her windows and doors were shaking as she could hear Cyclone Gita “roar”. “At this stage the wind is blowing so hard that the rain is coming in under our doors.”
Venaisi Tuilaga said on Facebook: “I’m here in Houma ... I just can’t describe the wind and rain here.”
Tooloo Charlies said: “Right now the wind is getting pretty bad, a mango tree has fallen into electric lines. Poorly built houses lost roofs.”
In a video posted on social media, several residents taking refuge in a Tongan church sang as they waited for the storm to hit.
Ariana Pupua, who posted the video, said they were “awaiting the cyclone with praise and worship”. “Jesus you are in control.” MetService meteorologist Bill Singh said Gita was still expected to develop into a category 5 cyclone, with sustained winds of 200km/h, and up to 250mm of rain.
The eye would pass about midnight 40km away from Tongatapu, which he said was “very close”.
Singh said a storm surge from the sea could add to the devastation wind and rain would cause to lowlying and coastal areas.
New Zealand retirees John and Margaret Swift, who live in TeeKui on the main island, said at 6.30pm that they were as ready for the cyclone as they could be.
Their house was made of concrete blocks and was built for hurricane-force winds. “The wind has been gaining in strength, there are still some people out on roofs nailing down and boarding up windows,” Margaret said last night.
Their house was all run on electricity so they went into town to get some gas bottles but most stores were sold out. “We were able to borrow a gas bottle from a friend.” Another Kiwi, Joanna Burke, said she expected the nation’s flimsily constructed homes to be devastated.
Most are made of blocks, corrugated iron and wood, and she didn’t expect them to fare well in the expected 200km/h winds.
New Zealander Richard Young, manager at Sandy Beach Resort on the outer islands of Ha’apai, said last night the worst he was expecting was winds up to 90km/h which was a stark contrast to the 200km/h winds expected on the main island.
“[However] we still moved all of our boats into safe locations, cleared the trees of coconuts, pulled shutters over exposed windows and any outdoor furniture is locked away.
“All of the guests have been given a briefing on what to do and when, and what to expect,” Young said. All but three had left the resort.
Oxfam New Zealand was on standby to provide aid for up to “70 per cent of the country’s population”.
Deterioration of sanitation could raise the risk of a second disaster due to the spread of dengue and other vector- and water-borne diseases.
Prime Minister Jacinda Ardern said last night New Zealand was on standby to help. “We’re . . . staying in very close contact.”
The cyclone is said to be the fiercest event ever to hit the country in its recorded history.
Hours before it came, locals were hammering planks of wood to windows and securing roofs.
Evacuation centres had been set up in nearly every village and people were able to shop for supplies again yesterday; Tonga’s Sabbath laws meant many stores had to remain shut on Sunday.
Sione Taumoefolau of Tonga Red Cross said cyclones that have hit the country in previous years had mostly affected the outer islands.
“This is the first time for those people in Tongatapu to experience a very strong cyclone coming through Nuku’alofa,” he said.
WeatherWatch said the cyclone was forecast to make “a direct hit” over the top of Tonga and the capital, Nuku’alofa, on the main island of Tongatapu late last night and early hours of today.
“Over 75,000 people are in the path of a storm already more powerful than anything New Zealand has ever seen, with torrential rain and damaging winds forecast to be averaging close to 200km/h and gusting over 230km/h by tonight [Monday] when it makes landfall there,” a spokesman said.
Among New Zealand aid agencies on the ground was Tearfund, which was working closely with its partner association in Tonga, ’Ola Fou. Emergency packs for families were being provided and they were also equipping evacuation centres.
Over the weekend the cyclone caused flooding and wind damage in the neighbouring nation of Samoa.
A state of disaster was declared there as authorities focused on rescue and evacuation.
There were no reports of injury or death and emergency services were focusing on people isolated.
American Samoa’s governor, Lolo Matalasi Moliga, said Gita had caused a lot of damage to homes and utilities there.
Singh of MetService said the weather system was more likely than not to reach New Zealand and if it did it would be an ex-tropical cyclone, but it was too early to be sure. “The consensus of most of the models is it looks like it’s going to turn towards us,” he said. “The models are basically agreeing now that the system will move across central New Zealand from late Tuesday to early Wednesday. But it’s still early stages.”
At this stage the wind is blowing so hard that the rain is coming in under our doors. Frederica Filipe
As Gita is now reminding us, tropical cyclones can be fearsome beasts. In less than a decade, and in the South Pacific alone, they’ve killed more than 100 people and cost nearly $2 billion in damage.
What fuels them?
Tropical cyclones are essentially low pressure systems that form and build over warm waters in the tropics — but with extreme characteristics.
Gale-force winds — or those higher than 63km/h — are found at low levels near their swirling centres but can fan out for hundreds of kilometres.
Meteorologists consider a “severe tropical cyclone” one that blasts as hard as 118km/h.
Gita is expected to be upgraded to category 5 — the highest grading possible, and one where wind speeds are greater than 196km/h.
Where and when do they form?
Each year, over the November-to-April season, about 10 tropical cyclones form in the Southwest Pacific basin.
Only a few of those ever reach category 4 strength, where mean wind speeds are 159 km/h or higher.
Vanuatu and New Caledonia typically experience the greatest activity, with an average of two or three named cyclones passing close to land each year.
This season, it had been forecast New Caledonia, Fiji, Vanuatu and Tonga could see two or more, while three or four severe cyclones of category 3 or higher were expected anywhere across the region.
At least one comes within 550km of New Zealand each year, usually around February and March.
Why are they ex-tropical cyclones by the time they get here?
To get to New Zealand, tropical cyclones have to make their way over much colder waters, while hitting strong upper-level winds as they move out of the tropics.
By the time they arrive, they are almost always reclassified as “extropical” cyclones.
That doesn’t mean they’ve weakened or been downgraded, but have morphed into a completely different type of beast.
And ex-tropical cyclones could still pack the potential for severe weather.
Under the right conditions, they could intensify and even muster lower pressures than they had before being reclassified.
Many of our most severe storms — such as last April’s Debbie, which brought the deluge that pushed a Rangitaiki River stopbank to breaking point, flooding Edgecumbe — have been ex-tropical cyclones.
What’s the anatomy of a tropical cyclone?
In the tropics, the strongest winds and most intense rain associated with a tropical cyclone usually occurs just outside the “eye”, or cyclone centre.
But after it has been transformed in what’s called an “extra-tropical transition”, the systems lose their symmetric cloud patterns.
The strongest winds and heaviest rain could then be found hundreds of kilometres from the cyclone’s centre — usually in a large area south of the centre. For meteorologists, that meant the position of the cyclone centre was no longer a good indicator of where the most severe weather would hit. How do we forecast and track cyclones? Across the world, there are six “regional specialised meteorological centres”, or RSMCs, and six “tropical cyclone warning centres”, or TCWCs, which are responsible for putting out advisories and bulletins in their regions.
MetService runs the Wellington TCWC, which monitors an area that stretches over the North Island and hundreds of kilometres east.
Tropical cyclone specialists track systems using several “ensemble” models that combine global and highresolution regional models.
One pulls together more than 50, while another combines more than 100.
Model “runs” are made twice a day, which forecasters use to produce new bulletins, and over busy periods, forecasters monitor the situation day and night.
The stronger that co-relating patterns in the models became, the more confident forecasters are in predicting where tropical cyclones will move around the region.
Unsurprisingly, the further out forecasters look, the less clear the picture is.
Do we know if Cyclone Gita will affect New Zealand?
MetService meteorologist Mickey Malivuk said models clearly showed Gita tracking towards New Caledonia later this week, and most indicated it would swing southeast towards New Zealand early next week. “But then they all diverge a bit.” It was still too early to tell where in New Zealand the system would make landfall — and it was still possible Gita might just carry on rolling westward.
“It’s still a fair way out for us to be sure.”
What role does climate change play?
Niwa has predicted ex-tropical cyclones will likely become stronger under climate change, and cause more damage as a result of greater wind speeds and heavier rainfall.
Climate scientists also predict there will be fewer of them.
“As time goes on, the number of tropical cyclones — and the number of storms generally — is likely to decrease a little,” Victoria University climate scientist Professor James Renwick said.
“But, when we get one . . . they’ll likely be stronger, with lower central pressure, stronger winds, and definitely more rainfall, because there is more moisture in the air.”
The drop in frequency could be explained by changes in the state of the atmosphere that would result in fewer storms being required to maintain the flow of heat from the tropics to the poles.
“It’s like the intensity gets concentrated into fewer events,” Renwick said. “Although, we are not talking vast changes — so while we get an average 10 tropical cyclones each season today, it might be around nine in the future.”