You ask the questions: Jim Salinger

© Herald on Sunday :  Sunday July 01, 2007

Why are there such extremes in weather between the top half of the North Island and the bottom half of the South Island? In Auckland we're enjoying mostly sunny days and down south they're under snow. Extremes in weather and climate during June have occurred because we have had more prevailing southwesterlies. The bottom half of the South Island has been very exposed to wintry blasts that have come up from subantarctic latitudes. At the same time, Auckland has been largely sheltered from the cold south or southwesterly winds, and the airflow has been off the warmer Tasman Sea.

Are you a climate change believer or sceptic? Have you noticed any major changes in your time in weather forecasting and if so, what has been the most surprising?

Climate has always changed over time. However, I agree with the latest Intergovernmental Panel on Climate Change 4th Assessment Report. This has concluded that warming of the climate system is unequivocal, as is now evident from observations of increases in global average air and ocean temperatures, widespread melting of snow and ice, and rising global mean sea levels. Most of the observed increase in globally averaged temperatures since the mid-20th century is very likely due to the increase in greenhouse gas concentrations. Major changes I have noticed in my time in climate research have been the shrinkage of mountain glaciers in New Zealand and worldwide, the warming of temperatures and the decrease in frosts.

There has been a lot of talk about rising sea levels and what that may do to some low-lying New Zealand properties. Is this something we will see in our lifetime do you think?

Tide gauges around New Zealand show that the sea level has risen by 16-18cm over the past 100 years. The projections of sea level rise indicate increases of half a metre by the end of the century. This could be more if the melting of Arctic Sea ice and Greenland is higher than anticipated. Coupled with this is the change in weather and climate patterns. Recent international climate reports highlighted that ongoing coastal development is likely to exacerbate the future risk to lives and property from sea level rise and storms. If development on the coast continues, then yes this will occur. However, with responsible planning, coastal property and lives will not be at risk.

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Climate-watchers give us the details

Monday July 02, 2007  Wayne Thompson 

Auckland's weather varies depending on where you live, be it in an urban valley, on top of a hill or down beside the sea.

That difference will be shown by a network of Weatherwise Auckland observers who will give Herald readers a broad coverage of the day's weather and 24-hour readings taken at 5pm.

Weatherwise principal Carla Salinger says measurements at four sites a day gives a better representation of what the weather is really like in Auckland.

The observers have weather stations set up at Freemans Bay for the inner city, and at Helensville, Orewa, Waiheke Island, Hillsborough, Henderson, St Johns Park, Beachlands, Waiuku and Pukekohe.

Some observers have been with Weatherwise Auckland for 10 years or more.  Henderson observer Albert Chan said his station was in a valley that was sheltered and warm during the day. But at night, it received cold airflows from inland. Over a year, Henderson's mean daily temperatures could vary from 20.1C to 9.8C.

Barbara and Roger van Ryn, of Beachlands, say their area has its own microclimate. "When the weather comes from the north, we get buckets more rain than anywhere," said Mrs van Ryn. "When it comes from the southwest we do not get as much rain as other places."

For 37 years, Waiheke Island resident Malcolm Philcox has been manning a weather station that has been in operation since 1914. His records show that last month there was 120mm of rain compared with 230mm in June 1924. "There was one particularly wet three-month period when 700mm was recorded, and I suggested farmers could start growing their sheep hydroponically," he said.

From left, Ron Catton, Carla Salinger, Albert Chan, Frits Schouten, Barbara van Ryn, Roger van Ryn and Malcolm Philcox. Photo / Kenny Rodger

Torrential rain surprises Wellington motorists

The Dominion Post | Monday, 2 July 2007

CRAIG SIMCOX /Dominion Post SMASH: One of the three cars involved in a crash ended up through the Basin Reserve fence. The crash happened during torrential rain.

Fifteen millimetres of rain fell in two hours at Kelburn yesterday afternoon, while 12mm fell at Wellington airport and 13mm in Lower Hutt, Mr Pascoe said.  "Those aren't huge numbers, but this narrow frontal band is taking its time getting over us."  Lumps in the front were causing short, heavy downpours, he said.  

NIWA announces free data policy

Thursday, 5 July 2007, 2:59 pm
NIWA announces free data policy

From this month [July 2007], the public will be able to download millions of pieces of climate, water resource, and other environmental information for free.

The National Institute of Water & Atmospheric Research (NIWA) is making access to its nationally significant databases free over the web. The initiative covers archived data on climate, lake level, river flow, sea level, water quality, and freshwater fish from NIWA, the MetService, and several other contributing agencies.

 “We hope our free data policy will encourage further scientific discovery and contribute to good natural resource planning and decision-making by giving everyone easy access to quality assured, scientific natural resources data,” says Dr Barry Biggs, NIWA’s General Manager of Environmental Information. “This also provides many new learning and research opportunities for school and university students. They can now explore this vast data resource to learn about New Zealand’s water and climate environment and perhaps discover things previously unknown to science.” NIWA’s initiative also makes these data readily accessible to overseas users.

Background

National Climate Database:

The database currently contains over 250 million individual data points. Data are from 7471 climate stations of which 2817 (38%) are currently ‘open’ (taking measurements at present). This includes 311 stations in the Pacific (restricted access – not free), and 4 stations in Antarctica.
- 202 stations have data before 1900.
- two stations have data before 1855.
- earliest station: Dunedin, Princes St, opened 01-Nov-1852, closed 31-Mar-1864.
- longest-running station: Chch Gardens, opened Dec-1864 & still open.
Observations include rain, temperature (earth & air), wind, soil moisture, evaporation, solar radiation, sunshine, pressure, humidity.
http://cliflo.niwa.co.nz

National Hydrological Database:

The database contains the equivalent of over 14 000 ‘station years’ of data. We have approximately:
- 220 open sites, with about 30 years of data each (6600 station years), and
- 750 closed sites, with about 10 years of data each (7500 station years).
- The earliest & longest running station: water-level/flow site, the Kaituna River at the outlet of Lake Rotoiti, installed in November 1905 & still operating.
Observations include river flow, river level, lake level, rainfall.
http://edenz.niwa.co.nz

National Water Quality Network:

77 water quality stations nationwide. Started in 1989.
The database currently contains about 600,000 data points.
Observations include cloud cover, water temperature, dissolved oxygen, water clarity, stream flow, and periphyton estimates. Once a year at selected sites bottom samples are collected to identify and count invertebrates.
http://edenz.niwa.co.nz

Sea level monitoring network:
http://edenz.niwa.co.nz

Freshwater fish database:
http://fbis.niwa.co.nz

Tornadoes rip through New Plymouth, southeast Auckland

Wednesday July 04, 2007

http://www.nzherald.co.nz/section/1/story.cfm?c_id=1&objectid=10449607&pnum=0

Graphic / Justin Matthews

Tornadoes have wreaked havoc today, with a twister tearing through New Plymouth early this afternoon and two people taken to Middlemore Hospital with injuries following a smaller tornado that ripped through southeast Auckland just before 4pm.  The Fire Service has had eight call outs to the Botany Downs and Golflands areas since the strong gusts in Auckland.

In New Plymouth, Taranaki Racing Club staff were seconds away from being caught by flying glass after the tornado swept over the local racecourse this afternoon.

The tornado tore through three kilometres of New Plymouth's CBD, tearing off roofs and scattering debris in its wake, this afternoon.

Eye witnesses said the tornado came in from the sea and announced its presence with a loud rumbling noise.

One of the first casualties of the twister was the PlaceMakers store in New Plymouth's CBD.

The roof of New Plymouth's PlaceMakers store comes to rest against a tree. Photo / Carey Davis

Senior Sergeant Robbie O'Keefe said the tornado had left a trail of destruction but there was no indication anyone had been injured.

The Radio Network's head weather analyst Philip Duncan said a huge band of thunderstorms was spreading into western areas.

"We are warning rain falls could be heavy enough to cause surface flooding during these embedded storms. Winds may easily reach gale force within seconds."

Mr Duncan warned regions south of Auckland and north of Taranaki were most at risk.

- NZPA, NEWSTALK ZB, NZ HERALD STAFF. TVOne:

North Island cleans up after tornadoes, Jul 5, 2007
The North Island is cleaning up after twisters struck on Wednesday afternoon. The first tornado spun ashore in New Plymouth at around 1pm and damaged half a dozen buildings leaving three people with minor injuries. At about 4pm another tornado ripped through part of Botany Downs in Auckland, lifting tiles from around 30 roofs and resulting in two people being taken to hospital.

The third twister struck in Tauranga at about 5:30pm, sending outdoor furniture flying and damaging at least two roofs.

MetService Ambassador Bob McDavitt says there may have been other twisters in remote areas.

The thunderstorms that spawned the spate of twisters that struck the North Island have passed but MetService says there is no guarantee similar weather conditions won't recur. McDavitt has some advice for people who look out their window to see a tornado bearing down. He says they should hunker down inside the safest part of the house and if there is time it's a good idea to open the windows to ease the pressure inside the house.

McDavitt says the winds near the centre of Wednesday's tornados were probably gusting around 100 kilometres an hour, with signs of twisting that would have created a sucking effect.

New Plymouth a tornado 'hot-spot'

NZPA | Thursday, 5 July 2007

Metservice severe weather forecaster John Crouch says the coastal areas around New Plymouth are a known "hot-spot" for tornados.

Taranaki was hit by a swarm of tornadoes on Thursday one day after a twister left a trail of destruction through the New Plymouth city centre.

The MetService said they were being caused by a series of thunder storms stretching 100km along the Taranaki coast

The western side of the North Island was the second most likely area to get tornados, after Westland.

"Anywhere from Auckland, Waikato, right down to the Kapiti Coast," Mr Crouch said.

In the South Island the terrain brought a lot of rain and thunderstorms, and strong winds were "turned" by the Southern Alps, sometimes triggering tornados.

"In the North Island the trigger tends to be north-easterly surface winds, which get a bit of friction over land, while the high-altitude winds aloft tend to be north-westerly, causing a turning effect.

"It tends to occur particularly during winter, when thunderstorms spawned in the Tasman are moving on to the west coast of the North Island, and hitting this specific wind profile".

The average frequency of tornado occurrence in New Zealand has been estimated by the National Institute of Water and Atmospheric Research (Niwa) to be over 30 a year, including an average of four in the Taranaki region.

Most New Zealand tornados and waterspouts are relatively small and are typically very narrow – with damage paths estimated to average 18m – and have short tracks. Experts estimate only about a third of them occur near people and are reported.

In one cluster of tornado activity near New Plymouth, a dozen tornados were reported between 1961-1975.  One of the most severe in recent times was three years ago at Waitara, which demolished a house.

That big tornado, on August 15, 2004, hit 16km northeast of New Plymouth and demolished all the main power lines feeding the area north and inland from Waitara, cutting off nearly 7000 consumers. It was particularly severe, with debris spread over an area 400m long by 50m wide.

Rated at a similar intensity, New Zealand's worst tornado was in Frankton and a nearby part of Hamilton on August 25, 1948, leaving three people dead and 80 injured.

On March 10, 2005, a waterspout formed over the sea just west of Greymouth and made landfall in Blaketown, then carved through the town centre.  Like the Frankton tornado, it was rated at F2 on the "fujita scale" indicating windspeeds of 150-200kph.  The Greymouth tornado caused almost $10 million in damage and seriously injured three people, but despite the magnitude of the tornado no-one was killed.

Tornadoes ravage Taranaki

Taranaki Daily News | Thursday, 5 July 2007

MARK DWYER/Taranaki Daily News

CHAOS: Tornadoes have ripped through the seaside township of Oakura, causing extensive damage.

MARK DWYER/Taranaki Daily News

I DID HAVE A ROOF: A sheet of corrugated iron ends up wrapped around a power pole after tornadoes ripped through the seaside township of Oakura.

A State of Emergecy has been declared in Taranaki after a swarm of tornadoes hit the area, as reports of damage flooded in, and the Metservice predicting more twisters across the country.

Senior Sergeant Geoff Ryan of New Plymouth police said that at 5.30pm during an electrical storm tornados hit the in Oakura, Egmont Village, Inglewood and the Waitara area.  A Civil Defence spokesman said at least six tornados hit the region.

Worst hit was Oakura, which has 40-to 50 houses sustaining damage of up to 80 per cent. Many of those houses are uninhabitable.

Civil Defence declared a state of emergency in Taranaki at 8pm, giving rescue services wide-ranging powers.  The National Crisis Management Centre was activated tonight in support.  A spokesman from the Ministry of Civil Defence and Emergency Management said the centre was activated at a monitoring level to be available to assist if required.  The main hazard was live power wires that were down.

Powerco said power was cut to 6000 homes throughout the region, affecting up 20,000 people. By 10pm power had been restored to about 2500.

- Additional reporting NZPA, Stuff.co.nz

Tornados wreak havoc in the North Island

Stuff.co.nz | Thursday, 5 July 2007

TREVOR READ/Taranaki Daily News

RIPPED APART: Firefighters look at the roof that was torn off Placemakers in New Plymouth by a tornado.

Why the spate of tornadoes?

Friday July 06, 2007

The series of tornadoes that have hit the west coast of the North Island in recent days has raised questions about why there has been a sudden concentration.

According to MetService, the reason is fairly simple - a combination of Antarctic cold air hitting warmer seas and creating thunderstorms.

New Zealand experiences, on average, about 20 moderate to strong tornado events each year and most have been reported in the North Island, particularly around the Bay of Plenty and Auckland.

Taranaki has also had it's fair share with 12 tornadoes between 1961 and 1975. But this week it has had as many as eight already, according to reports.

MetService Forecaster Oliver Druce said large thunderstorms were currently coming off the Tasman sea and the storms were "a breeding ground for tornadoes".

Colleague Bob McDavitt said: "The whole atmosphere is kind of sorting itself out after a break of cold air off Antarctica.

"It's accentuated a couple of fronts in the Tasman Sea and when they move onto the North Island, Taranaki takes the brunt of them.

"It's very cold air over the South Island, and the temperature difference is much stronger than normal. The temperature difference is what's causing the problem. It's slowly unravelling, but its going to take a while."

He said every thunderstorm had a "chimney, or bubble of rising air, in the middle".  When that rising air gets into the cold air above it turns to rain, so that causes some falling air. Mr McDavitt said: "In a normal thunderstorm that process ticks over reasonably well. But in a thunderstorm breeding a tornado, the cold air falls and encloses around the bubble of rising air and contracts it. So it squeezes the chimney of rising air into a tornado.' "It's unusual for us to get them all together, but it can happen."

How they happen

Tornadoes are caused when air is drawn into the base of a large thunderstorm cloud and accelerated upwards.

Any rotation in the air is concentrated - much the same as when a skater or dancer spins faster when they pull their arms in towards their torso.

The wind that is sucked into the storm begins to swirl and form a funnel, or tornado. The air inside the funnel begins to spin fast, creating a low air pressure which pulls even more air in.

Tornadoes are usually associated with clouds that have a strong up-draught, and clouds that have a strong up-draught are normally associated with thunderstorms.

Winds that change direction with height help to induce the spin of the air as it gets sucked into the thunderstorm.

With wind speeds as high as 300 kilometres per hour, a tornado can be very destructive when it reaches the ground.

Not uncommon in NZ

Tornadoes, or "twisters', are not uncommon in New Zealand, but most of the time they don't strike populated areas. A series of small tornadoes tore off roofs and downed trees in parts of Greymouth in May this year.

Roofs were blown off, iron strewn along streets, letterboxes blown from their bases and fences knocked over. Residents there recall a far worse tornado sweeping in from the sea and hitting the town in March 2005.

New Zealand's worst tornado struck Frankton in the Waikato on August 25, 1948.  The twister killed 3 and injured 80 others, and damaged or destroyed 163 buildings and 50 businesses.

-        NZHERALD STAFF, NZPA

-         

Tornadoes cause $7m damage, storms move north (+photos)

Friday July 06, 2007

A tornado in Wanganui uprooted a tree and upturned a bus shelter in Wanganui. Photo / Wanganui Chronicle

The thunderstorms which caused a series of twisters in Taranaki and Wanganui last night are now moving north. Storms are forming offshore across Northland, Auckland and the Waikato and conditions could be right for more tornadoes, Newstalk ZB head weather analyst Philip Duncan said.

A severe weather warning from MetService said a low in the Tasman Sea was expected to track across Northland early this afternoon and Auckland this evening. Heavy rain and thunderstorms ahead of this were due on Northland from late this morning.

A state of emergency was declared in the New Plymouth district last night after a series of tornadoes there left thousands without power and homes severely damaged. Early assessments from Insurance Council representatives put tornado damage in New Plymouth and Oakura alone at $7 million and rising.

Herald graphic

Taranaki Civil Defence said up to 50 houses were damaged in Oakura, where a tornado went straight through the town. Some were up to 80 per cent damaged and many were uninhabitable.

Jul 6, 2007 6:45 PM
Weather experts believe Thursday's twisters were some of the worst in recent times.

Taranaki is known to be a hot spot, but tornadoes are notoriously difficult to predict and are not even fully understood by scientists.

NIWA (National Institute of Water and Atmospheric Research) meteorologist Mike Revell says while they have the technology and science to be able to recognise the atmospheric conditions that are likely to produce tornadoes, the small scale of tornadoes makes them hard to forecast.

"You need a big strong vertical updraft basically, and the best way to get that is underneath a thunderstorm," says Revell.

MetService forecaster John Crouch says that the updraft of the thunderstorm is so strong it acts to stretch out the air that is being sucked in and concentrates it into a strong vortex. He uses the analogy of a spinning ice skater to explain.

"As she pulls her hands in she spins faster and faster...It's the same concept in that the air's being sucked into the thunder storm and it's being stretched out," he says.

Tornado intensity is measured on the Fujita Scale which ranges from zero to five - five being the most intense. New Zealand tornadoes are usually F0 whereas the large twisters in mid-Western United States can range up F5 with the ability to cause widespread destruction and death.

Kiwi tornadoes are usually around in the tens of metres wide and have tracks of just a couple of kilometres, but while they may not be on the same scale as America, they are not as rare as commonly thought. Around 20 tornadoes are reported every year in New Zealand, and the Taranaki region alone has had more than 50 twisters in the past 50 years.

Most occur on the west coast, and many more probably go unreported, blowing themselves out before they reach the gaze of civilisation.

Source: One News

Taranaki tornado seasons tracked

Monday July 09, 2007  Angela Gregory 

Houses in Oakura lost roof tiles in the swarm of tornadoes that hit the seaside town last week. Photo / Greg Bowker

A tornado strong enough to damage property and put lives at risk can be expected in Taranaki on average once every four years, according to research carried out by the National Institute of Water and Atmospheric Research (Niwa).

Principal climate scientist Dr Jim Salinger said there were 57 tornado "events" in the region from 1951 to 2006. Of those, 81 per cent did some damage and 21 per cent had inflicted major structural damage.

Dr Salinger said that on average about one potentially lethal tornado severe enough to damage property would hit Taranaki about once every four years.

Typical weather included the presence of low pressure and associated frontal activity over or west of Taranaki with winds from the north and west. The tornadoes would often track from the coast inland.

In studying past tornadoes, Niwa found most had maximum wind speeds in the 116-180km/h range, with 10 per cent attaining wind speeds in excess of 180km/h. Track or damage widths averaged 100m (range 15m to 500m) with a mean track length of 5km (range 1.5km to 16km). Dr Salinger said 70 per cent of tornadoes in Taranaki were reported in the New Plymouth district, especially in or near the city. The highest risk of tornado development occurred over the sea surrounding the region.

"The many reports of Taranaki tornadoes suggest many of these spawn as waterspouts over the sea and come in across the north Taranaki coast from the northwest."

He said it appeared that Mt Taranaki had little effect on the spatial distribution. Compared with other regions, Taranaki had a high rate of tornadoes, accounting for 12 per cent or more of the national occurrences, making it a relatively high-risk area, especially New Plymouth.The city lay within an area of relatively high wind speeds and the study showed the district was more at risk than other parts of Taranaki because of its exposure to thunderstorms and unstable northwest air masses from the Tasman Sea. Most tornadoes had occurred in this district with the worst causing major structural damage and some loss of life.

Debris from buildings was carried hundreds of metres and some even ended up embedded in other houses. Photo / Greg Bowker

Seasonally, the most tornadoes occurred in August, double the frequency of any other month, and the least in November, with none ever being reported in January. The most severe occurrences also occurred during August.

Dr Salinger said it was not known whether climate change would produce more tornadoes but gale- and storm-force winds from the west were likely to increase in Taranaki. The broad pattern of expected changes out to 2100 for New Zealand included increases in westerly winds.

Global climate models suggested that for mid-range temperature change projections, the mean westerly wind component across New Zealand would increase by approximately 10 per cent of its current value by 2050.

The highest wind speed expected to occur once a year could increase by about 3 per cent by 2080. Over the sea or flat land the annual frequency of occurrence of winds of 120km/h or more might increase by about 40 per cent by 2030 and 100 per cent by 2080.

Jul 6, 2007 8:02 PM
The inland Canterbury community of Methven had a solid snowfall on Friday morning, with locals reporting about 10 centrimetres on the ground. It also snowed steadily in Ashburton but wet conditions prevented snow from settling.

Grandson snatched from rampaging flood

Monday July 09, 2007 by Simon O'Rourke 

Five-year-old Henry Bredin was saved from the flash flood. Photo / Sarah Ivey

A grandfather desperately searched underwater for his 5-year-old grandson after a flash flood forced chest-high water through their Taranaki home. The flooded Kapikara stream swept through the home in a valley between Oakura and Okato about midnight Saturday. The little boy was almost swept away after being pulled from his grandmother's grasp but was saved after the 60-year-old grandfather, a smallholder, dived beneath the "tsunami-like wave" to search for the youngster.

As the water rose towards the ceiling, the trio fled to safety through a window.

Severe frosts create havoc in South Island

By BECK ELEVEN - The Press | Monday, 9 July 2007

PETER MEECHAM/The Press

WHITE WINTER: Brent Donald cycles through frosted tussock on his way to the top of Mount Grey in North Canterbury yesterday.

The most severe frost this winter caused icy havoc on South Island roads while the thaw burst water pipes, flooding homes and businesses.

The Fire Service was stretched yesterday with over 100 call-outs to watery chaos in homes, schools and commercial properties as sprinkler and heating systems burst.

Blue Skies Weather forecaster Tony Trewinnard said South Islanders could expect frosty mornings with fine days for the rest of the week.

He said the chilly southerly winds and the accompanying anticyclone promised dry but cold weather with no snowfall expected in coming days.

Fire crews in Christchurch, Dunedin and Invercargill were frantic with burst water pipes.

Icy roads have been blamed for two major South Island accidents.

Mount Hutt Ski Area manager David Wilson said more than 6000 people had visited the skifield over the weekend with record numbers on the slopes yesterday. "We had about 35cm (of snowfall) over Thursday and Friday and it's just made awesome conditions for skiing," he said.

Storm floods Far North, cuts power to 115,000 homes on way south

Flooding 20 minutes east of Kaitaia. Photo / Ike Urlich

Tuesday July 10, 2007

Some 115,000 homes are without power after torrential rain and strong winds struck the north of the country, isolating the Far North before moving into southern parts of Northland, Auckland and Coromandel.

Winds in excess of 140km/h are expected overnight in all three areas and police are advising residents to stay indoors and not use the roads unless "absolutely necessary". A state of emergency was today declared in the Far North after strong winds and flooding after a month's rain in 12 hours. The flood is considered a one in 100 year event with 254mm of rain in the Kaeo district alone.

Vector Energy spokeswoman Denise Bailey said 65,000 customers were without power in the Rodney district, between Wellsford and Orewa, and about 25,000 were without power on Auckland's North Shore.

Powerco said the winds and rain and caused outages to approximately 25,000 consumers on the Coromandel, Hauraki Plains and Piako areas.

There were several reports of uprooted trees and flying debris and a number of boats blown from their moorings on the Waitemata Harbour.

Lights on the Auckland Harbour Bridge were out and traffic delays were worsened when the median lane barrier was knocked out of alignment.

- ANGELA GREGORY, NEWSTALK ZB, NZPA

Jul 10, 2007
The National Crisis Management Centre in Wellington has been activated because of the worsening weather situation in the upper North Island.

The Ministry of Civil Defence says the centre is monitoring the situation in Northland, Auckland, Coromandel, Waikato and Bay of Plenty. Northland's Civil Defence has been activated due to the severe weather which has caused slips and flooding.

Deluge leaves trail of destruction

By KIM RUSCOE and RUTH HILL - The Dominion Post | Wednesday, 11 July 2007

JOHN SELKIRK/Dominion Post

WAITING FOR THE WORST: The Kerikeri River in full flood as it smashed into the bridge at high tide, after a month's worth of rain fell in less than 12 hours.

JOHN SELKIRK/Dominion Post

UNDER THREAT: Kerikeri's historic Stone Store was only metres from a raging torrent.

A state of emergency was declared in the Far North as a month's worth of rain fell in less than 12 hours, closing roads and leaving thousands of people without power or phones.
The little town of Kaeo, devastated by storms in late March, had 253mm of rain between midnight and 3am yesterday - a once-in-150-years event, according to hydrologists. At least 23 houses were flooded, with water up to a metre high in some places. Residents and emergency services were bracing last night for more rain, with MetService forecasting another deluge between midnight and 3am, coinciding with high tide.

Up to 100,000 households and businesses were without power last night. About 3000 homes were without power in the Far North, and more were believed to be without power in the Whangarei district.

Two motorcyclists were blown off their bikes on Auckland Harbour Bridge.

Thousands without power, roads remain closed after storm

A boat washed up on Waiake Beach near Long Bay. Photo / Paul Estcourt

Wednesday July 11, 2007
Thousands of homes north of Auckland and throughout the Far North are still without power and roads remain closed.

Homes in Northland could be without power until the weekend.

At Tiritiri Matangi, off the Whangaparaoa peninsula, a wind gust of 180km/h was recorded.

A number of businesses were broken into last night as thieves took advantage of the power black out that hit 140,000 homes and companies.

Inspector Les Paterson, area commander for Takapuna on Auckland's North Shore, said seven businesses there were targeted. He did not believe they would have been the victim of break-ins in normal circumstances.

"Business owners need to think about camping out if the power has failed," Mr Paterson said.

Up to 60,000 homes in Auckland remained without power this morning after about 140,000 Vector customers were without power at some time overnight.

The Sky Tower closed due to the high winds and ferry, rail and road transport was disrupted. Ferries were running again this morning.

In Northland, up to 5000 homes were without power and Whangarei Hospital was using an emergency generator.

All roads leading to Whangarei were blocked this morning as a result of flooding and slips.

- with NZPA

$2m storm warning system for Bay

11.07.2007

By JOHN COUSINS

Life-saving technology enabling pin-point tracking of storms across Bay of Plenty is to be introduced by MetService in about two years.

Construction of a new weather radar station in the ranges between Tauranga and Rotorua will take the guesswork out of predicting the path and severity of thunderstorms.

Funding for the $2.5 million station in the Mamaku Range has just been announced by the Government as part of a $10m initiative to introduce weather radars into Bay of Plenty, Taranaki and Hawke's Bay/Gisborne.

Details have emerged as a furious storm battered parts of the North Island yesterday afternoon and overnight.

MetService chief forecaster Rod Stainer said the advance warning system would eliminate the situation in which the intensity and direction of the storms which devastated Tauranga and Matata in May 2005 could

be forecast.

Tauranga was at the limit of Auckland's weather radar and the curvature of Earth meant it could detect weather only about 6km high. "You lose a hell of a lot of information at that point."

Mr Stainer said the radar station would supply precise short-term warnings of localised weather events - down to which suburbs and townships would be hit, when a storm would strike and the volume of torrential rain.

It would mean emergency services could react proactively and close a section of road that regularly flooded or issue a general warning to low-lying homes in the path of the storm.

Mr Stainer said people would notice little difference in day-to-day forecasts, which could not be as precise because they covered such big areas in few words.

However MetService would be able to update local forecasts with short-term information from the radar, such as if a bank of thunderstorms was coming through.

"The key purpose of weather radar is to monitor severe localised events, try to give predictions on the quantity of rainfall, where it will go in the next hour and which areas need to be on standby."

The weather radar was also a very popular tool for people accessing graphics on the MetService's website: www.metservice.com

Radar readings on wind speed and direction were also useful for fishermen.

Tauranga Mayor Stuart Crosby said the radar was good news. The region's mayors had lobbied hard to get a radar station here because of the importance of quality localised weather information.

-with Michele McPherson and NZPA

Forecast grim for insurance companies, local bodies

Saturday July 14, 2007 By Derek Cheng 

Arabella Sampson, 6, hitches a ride on Ebony Lamb on the ski slopes at Turoa yesterday. The Wellingtonians were making the most of the last weekend of the school holidays. Photo / Alan Gibson

Extreme weather driven by climate change is expected to become more intense and more frequent, pushing up insurance premiums and causing headaches for local authorities.

Jim Salinger, principal scientist at the National Institute of Water and Atmospheric Research, said the consequences of climate change could not be avoided.

"As it gets warmer, floods, landslides, droughts and storms are very likely to become more frequent and intense. A one-in-20-year event could become a one-in-five-year event."

Dr Salinger said a predicted increase in westerly winds made future heavy rainfalls in western regions and droughts in the eastern regions more likely; already this year debilitating droughts have struck Hawkes Bay and parts of the Wairarapa.

Though highly populated areas - including Auckland and Wellington - are not expected to suffer the worst of weather changes, the overall rise in temperature will still increase the likelihood of storms.

But the exact impact was unknown because there were several contributing factors, including how carbon emissions are curbed.

Dr Salinger said the atmosphere could hold 8 per cent more moisture for every 1C rise in temperature, but projections for rises vary; the increase in Northland by the 2080s is between 0.6C and 4C.

It is up to each local and regional authority to monitor and deal with climate issues and related risks.

Auckland City Council says a one-in-50-year rainfall would flood 860 homes across the city.

Developers cannot build properties within 20m of the shoreline in parts of Manukau, where the council is tendering research to find out more about climate change.

Insurance Council chief executive Chris Ryan said areas more vulnerable to weather extremes included pockets of the Far North, East Cape and the South Taranaki coast.

Property owners might find it difficult to get insurance unless they were prepared to pay higher premiums.

Climate-related hazards cost insurers $800 million last year, and this year's bill looks equally ominous, including $7-10 million for the tornadoes in Taranaki, $5 million for the cold snap in the Deep South and at least $10 million each for Northland, Auckland and the Coromandel Peninsula for this week's extreme weather.

Far North Mayor Yvonne Sharp has called for more powers for local government to stop developments that put people and their homes in danger. At present, councils can prevent such developments, but the Environment Court can overturn their decisions.

Picturesque but treacherous

By STAFF REPORTERS - The Southland Times | Tuesday, 17 July 2007

BARRY HARCOURT/Southland Times/Image ID 108120

STILL LIFE: A heavy hoar frost painting a perfect postcard shot near Omakau yesterday.

The south's chilly mornings are set to continue at least until the weekend, according to the MetService.

Forecaster Geoff Sanders said a big ridge of high pressure sitting over the bottom of the South Island was to blame for the regular visits from Jack Frost.  Jack appears to have his feet firmly planted with temperatures set to continue plummeting to below zero most nights this week. "What you see is what you're gonna get, really," Mr Sanders said.

Invercargill's maximum temperature today is expected to reach 4degC while Queenstown is expected to reach 5degC.  Mr Sanders said the high pressure was also creating inversions, especially in central regions.

"Normally as you go higher the temperature decreases, but under these inversions the temperature actually increases as you go higher.

So it traps in fog and that sort of stuff," he said.

The frosty nights were causing many roads to remain treacherous.

Throughout Central Otago a hoar frost gripped the landscape.

The Clutha Valley road was badly affected by ice yesterday.

Torrential rain causes chaos in Hawke's Bay

Tuesday, 17 July 2007

NZPA

DRENCHED: A parent leaves the school through the flood water to help rescue kids from Puketapu School, near Napier, New Zealand.

KIM POWER

EVERYBODY OUT: Staff and students from Maraekakaho school had to be evacuated by the army via unimog after water flooded their school.

Houses were evacuated and schools and businesses closed today as torrential downpours caused severe flooding in parts of Hawke's Bay.

A Ministry of Education spokesman said eight schools in Hawke's Bay were closed due to flooding.

Maraekakaho School west of Hastings and Puketapu School west of Napier were the worst affected with water rushing through classrooms at one stage at Maraekakaho and school grounds left under water at Puketapu.

Others, including Napier's Hukerere College, were closed voluntarily.

Five houses at Maraekakaho were evacuated, with residents temporarily relocated to homes of friends and family.

Other residents in the rural Napier-Taihape Rd area were trapped by high water levels across roads.

The Hastings suburb of Flaxmere was the worst of the urban areas to be affected with businesses and public centres such as the local library and swimming pool complex forced to close because of flooding.

Soldiers from the army's Napier-based Wellington Hawke's Bay battalion were put to good use in the Maraekakaho and Puketapu communities after the flooding.  Four Unimog trucks were dispatched to the areas at the request of police this morning.

-NZPA

More schools closed in flood-hit Hawkes Bay (+photos)

People help out at Puketapu School yesterday. Photo / Hawke's Bay Today

Wednesday July 18, 2007 By Juliet Rowan  and Edward Gay 

Three more schools have been closed by flooding in Hawkes Bay today.

Tikokino Principal Damien Kinsey says there is no flooding at the school, but slips and debris on State Highway 50 have meant most of the school's 63 pupils were not able to make it to class.

The other schools to close are Onga Onga and Sherwood.

The area is experiencing heavy rain for the second day in a row, after flash flooding yesterday closed schools and businesses and forced the evacuation of homes. Metservice is forecasting a further 120mm today and the rain will continue into the weekend, said forecaster Oliver Druce.

Brrrr ... yesterday morning coldest this year

Tuesday July 24, 2007  By Angela Gregory 

Photo / Northern Advocate

Aucklanders who yesterday had to cope with the coldest start to any day this year can take comfort in that it was probably as cold as it will get this winter. MetService forecaster Bob McDavitt said readings taken at Auckland Airport at dawn recorded a 1C air temperature and a - 4C frost, making them the coldest temperatures recorded for the city this winter. Henderson was even colder with a - 1C air temperature and - 5C frost. Whangarei also had its coldest morning this winter with an air temperature of 2C as did Rotorua with - 3C. Tauranga's - 1C was equal to the morning of July 14.

Mr McDavitt said the frosty morning in Auckland was due to clear skies, no wind and relatively low moisture levels on the ground due to fine conditions on Sunday. Yesterday's frost was only moderate, not the first this winter and not a record breaker. Auckland usually got more frosts.

South mops up after floods

Tuesday July 31, 2007

A jogger in Dunedin. Photo / Otago Daily Times

Four homes in Palmerston were evacuated last night with water waist deep running down State Highway One "like a river".

Waimate District Council spokeswoman Carolyn Johns said the roads around Morven, 34km north east of Oamaru, were extremely dangerous and the township itself had been flooded.

Environment Canterbury flood control spokesman Philip Lees said the rain was mostly in the northern part of South Canterbury, in the foothills. The rain started falling heavily late last night.

Ecan measuring equipment in Waimate recorded 42mm of rain falling on the town in four hours.

Dunedin Civil Defence spokesman Neil Brown said residents reported flooding in flat areas of Dunedin, including Mosgiel and parts of South Dunedin.

No-one was evacuated by Civil Defence, though some people in Dunedin chose to leave their homes overnight because the sounds of water nearby made them uncomfortable, he said.

According to rain gauges on the regional council's website, the Pine Hill station has recorded over 73ml in the last 24 hours.

"Last night when I left the office I went down to the Leith, she was a raging torrent - really wild. But I would think it's quieting down a hell of a lot," Mr Chin said.

- NZ Herald staff, NZPA