The worst is yet to come.
That’s the message from Canterbury Civil Defense, as the area braces for two expected days of heavy rain, the subject of a rare red weather warning from MetService.
By 8 p.m., 31 mm of rain had fallen in Methven, 26 mm in Geraldine and 20 mm in Darfield since the red warning went into effect at 3 p.m. on Saturday. It is expected to stay in place until 11 a.m. on Monday.
What’s the weather like where you are? Send an email to [email protected]
Christchurch and Timaru have so far been spared heavy rainfall with only 5mm of drop.
* Winter is coming: eighth frost on the ground recorded in freezing May for Marlborough
* Cold snap continues in southern Canterbury with torrential rains forecast for the weekend
* Weather: deep depression causes big waves, coastal flooding in the east, with the possibility of more to come
But with the red warning, only the second time that MetService has issued such a warning since the color coding system went into effect in mid-2019, the persistence of rain for an extended period has remained the biggest concern. .
“Certainly the rain is falling as expected,” said Sonja Farmer, metService meteorologist.
“This event is expected to take place over the next 40 hours until Monday morning, so we expect there will be a lot more rain.
“The problem is that a lot of the rain will fall in the highlands, and rivers will be as much of a problem as the rain that falls in urban areas,” Farmer said.
Canterbury Regional Civil Defense (CDEM) duty officer Andrew Howe said they continued to make contact with key agencies, including local councils.
“It is certainly still a model of waiting from an emergency management perspective. Local authorities from Kaikōura to Waimate and Mackenzie have done a lot of preparation to make sure their emergency operations centers are up and running.
“I don’t think we’ve really seen the worst yet. The worst is yet to come, ”Howe said.
MetService meteorologist Tom Adams said on Saturday evening that the biggest impact would come from the “longevity and persistence” of the rain, rather than short bursts of rain.
“It’s only the precipitation that accumulates hour after hour, especially in headwaters, that is going to cause swelling of rivers and potential flooding,” Adams said.
By 5 p.m., parts of Canterbury had already registered up to 10mm of rain in the past hour.
“It’s a lot of rain for them, but it’s not a question of hourly quantities. It’s a question of how this will stack up over the next couple of days.
“While everything seems to be going according to plan at the moment, we still have a lot of hours to come.”
Emergency Preparedness Centers are preparing to respond once the full force of the weather event begins to be felt, Regional Duty Officer Andrew Howe said.
“We’re basically in a waiting pattern,” Howe said. ” We are waiting. “
For now, Civil Defense relied on MetSevice updates as its “source of truth,” but expected to have a clearer picture of the situation by 6 p.m. Saturday.
Red warnings are only for the most extreme weather events, and there has been only one other such warning since the color coding system was introduced in mid-2019 – the other in February 2020 when massive precipitation trapped 1,000 people in Milford Sound.
MetService communications meteorologist Lisa Murray said the rare red warning was important and people should act now to protect people, animals and property from the impact of weather conditions.
“People should also be prepared to take advice from official authorities and emergency services,” Murray added.
Dangerous river conditions and flooding were expected in Canterbury, with slips and floodwaters likely to disrupt travel, render some roads impassable and potentially isolate communities, MetService said.
Rain is expected across the country, and there will likely be heavy snowfall and thunderstorms in some areas, while MetService is also concerned about the possibility of coastal flooding in Auckland, Bay of Plenty and Canterbury so that high tides combine with a strong swell.
Waka Kotahi NZ Transport Agency has asked motorists in Canterbury to prepare for disruptions to the road network, with the heaviest rainfall in 10 years forecast for the region.
The weekend promises to be rather wet in some regions.
The forecast precipitation could cause widespread flooding, land instability and for some rivers bank rupture, said Wayne Oldfield, senior director of maintenance and operations for the NZTA.
Preparations were in place if precipitation reached expected levels. “People should plan ahead by checking the forecast before leaving and keeping an eye on our website and social media for updates and road closures.”
In the Bay of Plenty, Coromandel Peninsula, Auckland and Northland, motorists have been advised to watch out for storm surges and surface flooding as strong swells coincide with high tides.
MetService’s red severe weather warning covers Canterbury south of Amberley from 3 p.m. Saturday to 11 a.m. Monday. Up to 300 mm could fall during this period in Canterbury High Country and the foothills, with up to 120 mm in the plains and on the coast.
Heavy snowfall could also fall up to 1,000 meters in Canterbury, and southerly to south-easterly winds could approach strong gales in exposed areas of the plains and on the coast from Sunday afternoon into the night.
There is a more usual orange heavy rain warning for Nelson west of Motueka during the 6 p.m. until 3 a.m. Sunday, and for the eastern areas between Amberley and Kaikōura during the 48 hours onwards. from 3 p.m. on Saturday.]
Heavy rains are also possible elsewhere in the eastern South Island, with heavy rain monitoring Marlborough between Ward and Kaikōura until 11 p.m. Saturday, the Richmond Range until 9 p.m. Saturday and for North Otago and Dunedin. from Sunday afternoon until the beginning of the year. Monday.
In the North Island, heavy rains are possible for Bay of Plenty east of Whakatāne until 3 a.m. Sunday, and for Taranaki towards and north of the mountain until 6 p.m. Saturday.
There is a risk of thunderstorms in many parts of the North Island and the South Island summit on Saturday.
Hail up to 15mm in diameter was possible during any thunderstorm for Northland, Auckland and west to north Taranaki, MetService said. Small tornadoes were also possible and winds could blow up to 90 km / h.
Gusts to 90 km / h were also possible during thunderstorms for the Coromandel Peninsula and Coastal Bay of Plenty, as well as small hail. Small tornadoes were possible over the Coromandel Peninsula.
Heavy precipitation is brought to Canterbury by a complex low pressure system that is expected to slowly move southeasterly through northern and central New Zealand over the weekend. A strong and humid south-easterly flow was expected to cross the South Island, which would bring rain.
An associated front is expected to move east into northern and central New Zealand on Saturday, MetService said. It was expected to bring a relatively short gust of heavy rain to some areas.
Another front was due to move into Otago from the east on Sunday, causing a period of heavy rain over Dunedin and northern Otago.
In Westland, south of Hokitika, and in Fiordland, gales from the southeast could sometimes reach 120 km / h from Saturday afternoon to Monday morning.