Tropical cyclone Gita leaves trail of destruction in Tonga

Cyclone Gita: 'it's the worst situation I have been in'

Defence Force personnel clean up in Tonga. 

RadioNZ,

13 February, 2018

Tonga's emergency services are heading out to assess the damage after Tropical Cyclone Gita left a trail of destruction overnight.

Defence Force personnal clean up in Tonga. Photo: Supplied / Solomone Savelio

On Tongatapu, the category four cyclone brought winds of over 233km/h which ripped roofs off houses, brought down trees, destroyed a Catholic church, and took the Tongan Met Office and the national radio station off line.

There are unconfirmed reports two people have been killed.

Emergency services and His Majesty's Armed Forces are heading out to assess the damage this morning.

Graham Kenna from Tonga's National Emergency Management Office said the capital Nuku'alofa has been severely damaged.

"I've been involved in disaster responses for 30 plus years and it's the worst situation I have been in."

There has been major destruction, Mr Kenna said.

"A lot of the landmark buildings are extremely badly damaged or even destroyed, the landmark tree ... near the palace, has been been destroyed.

"It's quite a bad situation."

The armed forces were rescuing people throughout the night, including a woman who was in labour and a man who was very badly injured.

Mr Kenna said it was very difficult to get around Nuku'alofa and although he only lives about 1.5km from his office, it took him 25 minutes to drive home due to downed power lines and debris on the roads.

Power and water supplies are out in Nuku'alofa and not even tank water was likely to be available because many tanks had been blown over, Mr Kenna said.

As soon as the worst of the wind was over, the armed forces began to clear the roads, said Mr Kenna.

"We wanted to make sure that once dawn breaks if we needed to get people to hospital we were able to do it."

He said a curfew would remain in place in Tonga for the rest of the day.

The fact that there was no storm surge because the worst of the cyclone hit at low tide and that the cyclone did not last as long as was expected were the only positive aspects, Mr Kenna said.

The New Zealand government has pledged an initial $50,000 to assist rescue and relief operations in Tonga.

"So really it's just a matter of hearing from the Tongan government about what their needs are, and we will be ready to deploy," Prime Minister Jacinda Ardern told Morning Report.

Fiji's MetService said the category four storm was very close to being upgraded to the highest category, five.

The US Joint Typhoon Warning Centre earlier said it was hitting maximum sustained winds estimated at 233km/h.

Well-built framed homes can be damaged in category four winds, and most trees will be either snapped or uprooted and electricity and water outages could last anywhere from several days to weeks after the storm.

Authorities last night switched off the electricity for about 75,000 residents who live on Tongatapu.

About 1000 families heeded the warnings and took shelter in evacuation centres early yesterday afternoon.

Graham Kenna said the New Zealand and Australian governments had emergency supplies on standby and emergency funds were available.

"We can hit the ground running. We're just dividing up our teams now so that as soon as we can get out there, we're out doing an assessment.

"We'll start in the city and then we'll fan out into the countryside and get a full grasp by mid afternoon on what the needs are going to be," Mr Kenna said.

Cyclone Gita - what you need to know

MetService‏Verified account @MetService

Latest trackmap from Fiji showing where #Gita is meant to be heading. For further updates go to http://www.met.gov.fj  ^Cam

11:57 AM - 12 Feb 2018

RadioNZ,

13 February, 2018

Tropical cyclone Gita hit Tonga overnight, destroying a church and homes and sending roofs flying.

Fiji's Meteorological Service said Gita's central pressure overnight was stronger than Hurricane Harvey when it made landfall along the Texas coast in the US late August 2017.

Tonga

Unconfirmed reports of two dead

Tongan Met Office roof in Tongatapu ripped off, equipment affected and offices evacuated

Winds estimated at 233km/h - US Joint Typhoon Warning Centre

A Catholic church completely destroyed

State of emergency declared to help prevent loss of life and damage to property

Capital Nuku'alofa severely damaged, power and water out, many landmark buildings 'destroyed'

Power turned off for 75,000 residents in Tongatapu

Fiji

Gita is expected to strengthen as it heads towards southern Fiji, which it should pass over later today.

American Samoa and Samoa

Massive cleanup under way across Samoa and American Samoa

Fears about sanitation and the spread of mosquito-borne dengue fever

People advised to boil all water

Schools closed

Emergency teams working to restore power and running water to thousands of households

Live: Tropical Cyclone Gita smashes Tonga, moves towards Fiji

The warming Atlantic waters

North Atlantic May Cough up Another Out of Season Tropical Cyclone this Week

Robertscribbler,

17 April, 2017

Like pretty much everywhere else in the world ocean these days, and due primarily to a rampant injection of greenhouse gasses into the Earth’s atmosphere through fossil fuel burning, the North Atlantic is now considerably warmer than during the 19th and 20th Centuries…

Warming Waters and An Angry Jet Stream

That extra heat provides more available fuel for tropical storm and hurricane formation. It increases the top potential peak intensity of the most powerful storms. And it extends the period in which such tropical cyclones are capable of forming — for sea surface temperatures of at least 70-75 degrees Fahrenheit are often necessary to fuel such systems (please also see the present science on how climate change is impacting tropical cyclones).

(Sea surface temperatures in the North Atlantic now range between 1 and 7 degrees Celsius above average for most regions. These warmer than normal sea surfaces provide more fuel for storms even as they extend the period during which tropical storm and hurricane formation is possible. Image source: Earth Nullschool.)

But it’s worth noting that warm ocean waters are not the only ingredient that add to the potential for the formation and strengthening of these powerful storms. Instability and cloud formation are often necessary to seed such systems. 

And the more extreme warm and cold temperature anomalies associated with wavier Jet Stream patterns inject exactly this form of instability into the middle latitudes at a higher rate than was witnessed during past decades.

Due to its proximity both to a melting Greenland and to a rapidly warming Arctic, the North Atlantic is particularly vulnerable to the production of powerful swirls of warm and cold air. Warming tropics collide with the cold air producing pools of glacial freshwater melt and the enlarging meanders of the Northern Hemisphere Jet Stream. And it’s the proliferation of these unstable vortices forming over warming waters throughout the North Atlantic that may start to generate a more and more noticeable higher incidence of both out of season cyclones and stronger storm systems.

(A persistent swirl of disorganized clouds in the Central North Atlantic — continuously re-charged by frontal systems sweeping down from Baffin Bay and feeding on warmer than normal sea surface temperatures may become the first tropical cyclone of 2017. If it later forms into a tropical storm, it will become the third out-of-season named storm to form in the Atlantic over the last 15 months. Image source: LANCE MODIS.)

Last year, extremely warm sea surface temperatures combined with this kind of observed instability 

to spur the formation of Hurricane Alex during January. Tropical storm Bonnie also formed out of season during May. Similar very warm ocean conditions then helped to kick-start the late November formation of Category 3 Hurricane Otto (though November is still technically hurricane season, it’s supposed to be very rare to see so strong a storm form so late in the year).

Possible April Cyclone Underlines Recent High Incidence of Out of Season Storms

Fast forward to April of 2017. According to the National Hurricane Center, there’s now a 30 percent chance that a tropical depression may form in the Central Atlantic over the next 48 hours. Ultimately, such a system could gather into the first Atlantic named storm of 2017 — Arlene. Such an event would mark the third time in just 15 months that the Atlantic basin had produced an out-of-season tropical storm or hurricane.

(A vast majority — 97 percent — of tropical storms and hurricanes in the Atlantic form during hurricane season from June 1 to November 30. That said, human forced climate change may now be in the process of providing more fuel for the formation of out-of-season storms. Image source: North Atlantic Tropical Cyclone Climatology.)

Incidence of out-of-season tropical storms or hurricanes in the Atlantic is rather rare. Over 158 years from 1851 to 2009, perhaps one such system formed, on average, each year. Moreover, these storms primarily formed during May — which by itself produced more out-of-season storms than December through April combined. And a vast majority of these systems were tropical storms — not hurricanes or major hurricanes.

In 2016 and 2017, Alex formed as a hurricane during January — which is practically unheard of. Bonnie formed during late May, which was less unusual but still out-of-season. Otto formed as a category 3 major hurricane during late November — another anomalous event. Meanwhile, if Arlene forms this April it will represent 1 out of only about 20 such systems that formed during the month in the period of 1851 through 2009.

But even if we don’t get a tropical cyclone in the middle of the North Atlantic during April of 2017, it’s becoming increasingly obvious that conditions have changed. That forecasters now need to be more alert for out-of-season tropical cyclones and to the various new weather phenomena that are now being precipitated by a warming climate.

Links:

The National Hurricane Center

Hurricanes and Climate Change

Earth Nullschool

LANCE MODIS

Extreme Weather Events Linked to Climate Change Impact on Jet Stream

North Atlantic Tropical Cyclone Climatology

Hat tip to Vaughn

Hat tip to Hilary