The winter storm has caused flooding, power outages and road closures. Send your weather videos and pictures to news@tvnz.co.nz.

10.00pm: MetService has tonight issued a new severe weather warning for heavy rain and severe gales for parts of central and southern New Zealand.

Heavy rain is falling over parts of Canterbury and Otago.

The heaviest falls are expected in Canterbury south of Arthurs Pass and about eastern Otago where a further 60mm of rain could accumulate through to Saturday morning in addition to what has already fallen.

Snow is likely to lower to 400 metres over Central Otago and northern parts of Southland tonight, and to 800 metres about the South Canterbury High Country overnight.

Severe gale northwesterlies gusting 120 km/h are expected in exposed parts of Wellington and Wairarapa tonight, while Westland and Fiordland can expect severe southeast gales gusting 140 km/h until late Saturday morning.

The combination of heavy rain and strong winds is expected to cause widespread disruption to transport, flooding and slips.

Also, in the South Island, wind chill due to cold temperatures and blizzard like conditions at higher levels could cause stress to livestock, while snow is likely to affect some higher passes and roads in the far south tonight and tomorrow morning.

Large south to southeast waves may cause coastal inundation along the South Canterbury and Otago coasts during tonight and Saturday.

The low is forecast to slowly move away to the east on Saturday.

9.30pm: Otago Civil Defence staff are actively responding in Waitaki, Dunedin, Clutha and Central Otago districts as rivers are rising rapidly.

Evacuations are underway in Henley, within the Dunedin City boundary.

Otago Regional Council says there are also reports of streams overtopping in Lawrence and Ida Valley with reports of a small number of self evacuations.

9.22pm: The New Zealand Defence Force has confirmed it has tonight sent nine trucks, an ambulance and about 20 soldiers to help tackle the floods in Canterbury and Otago.

Sixty more troops have been placed on on standby as the powerful storm continues to sweep across the South Island.

Major Brett Grieve, second in command of the 3rd Combat Service Support Battalion, said the trucks and ambulance were making their way to flood-stricken Timaru.

An Army officer is leading the 20-member contingent and has been assigned to work in Timaru’s Emergency Operations Centre. Another two are liaising with Otago’s Regional Coordination Centre in Dunedin.

"The Emergency Operations Centre in Timaru has not yet given us specific tasks but we are prepared to help those in affected areas by evacuating people, distributing sandbags and delivering food and other vital supplies," Major Grieve said.

"We are closely monitoring the situation because the flooding is expected to get worse overnight."

9.00pm: Timaru District Council says residents in the following low-lying areas have been advised to self evacuate: Butlers Huts, Milford Huts, Stratheona Huts, Saltwater Creek - Redruth Area.

The council says anyone in these areas or elsewehere who feels unsafe or unsure can choose to evacuate.

The following areas are now isolated in terms of State Highway access: Waimate, Makikihi, St Andrews, Pareora.

This will be throughout the night and may extend into tomorrow.

The council says please stay put, but if you have to travel please check road conditions.

8.35pm: A regional state of emergency has been declared in Otago tonight, in support of Dunedin City and Waitaki Districts, which have both declared local states of emergency in their own jurisdictions.

Evacuations are occurring in some low-lying areas of Oamaru, Mosgiel and Dunedin and in Waimate.

Civil Defence says Mosgiel is the worst affected area and people should self-evacuate if they do not feel safe.

A house in Oterahura is also being evacuated and emergency management staff are assessing the extent of flooding in the Ida Valley.

Highways and local roads are also closed by flooding.

Otago Regional Council’s flood managers are closely monitoring the Silver Stream, which has begun to overtop the spillway at Gordon Road and flood rural land outside Mosgiel.

8.25pm: Dunedin Civil Defence is telling residents in low-lying areas who feel concerned to make plans to evacuate, or self-evacuate themselves to stay with friends or family who live on higher ground should it be required.

With a state of emergency declared in Dunedin City tonight, Civil Defence Controller Sandy Graham says residents should check on neighbours, particularly if they are vulnerable.

Due to heavy rain infiltrating into the wastewater system, manhole covers have been forced up in Surrey Street, South Dunedin, and on North Road in North East Valley. People should stay out of floodwaters in these areas and treat them as contaminated. The council has opened all available bypasses to alleviate pressure on the system.

A number of road closures are now in place, including State Highway 1 at Waikouaiti.

Ms Graham says motorists should not go rubbernecking, or put themselves or others at risk.

Anyone wanting to report flood-related issues with DCC services should call 03 477 4000 to report it. Anyone who feels their safety is in danger or has water entering their house or business should call emergency services on 111.

8.00pm: Mayor of Dunedin Dave Cull has declared a state of emergency for Dunedin City in response to issues arising from heavy rain in the city today.

The state of emergency has been declared because the emergency situation is beyond the resources of the emergency services alone, or otherwise requires significant co-ordination. It means extra powers are available to assist in the emergency response.

Dunedin Civil Defence Controller Sandy Graham says Civil Defence is making plans to evacuate people from some areas in Mosgiel.

7.32pm: The army is in Timaru to back up Civil Defence during the flooding emergency. The Milford huts and the Rangitata huts have been evacuated.

7.15pm: The bleak weather is set to linger into the weekend, with still more rain and wind across New Zealand tomorrow.

6.40pm: The TDC has confirmed evacuations are being carried out near Rangitata.

6.20pm: Alpine Energy in Timaru says there will a number of people without power tonight as weather conditions have meant it is now unsafe to continue to work on the power lines.

Households in Otipua township, Rosewill, Temuka and Pleasant Point are affected.

The company says teams are ready to start again first thing tomorrow morning when hopefully conditions have improved and it aims to have the power on by tomorrow afternoon.

6.05pm: A man stranded on the roof of his car in Oamaru has been rescued by a farmer with a tractor.

Police received a call from the man shortly before 5.30pm that he was stuck on the roof of his car on Weston-Ngapara Rd which flooding has made impassable.

6.00PM: Ashburton District Council advises that more roads have been closed in the district by flooding, and the community is advised not to travel south on either State Highway One or Thompsons Track, as both will be closed.

NZTA will be closing State Highway One from Dunsandel.

5.40pm: The Otago Regional Council’s flood management team advise that the following rivers are rising steadily: the Kakanui, Shag and Taieri Rivers, the Silver Stream, Water of Leith and the Lindsay Creek. The rivers are expected to continue to rise overnight and will be monitored.

5.35pm: The Highlanders are struggling to get to Christchurch for their Super Rugby quarter final match against the Crusaders tomorrow night.

Highlanders first five-eighth Lima Sopoaga tweeted that Dunedin's Forsyth Barr Stadium could host the game.

5.20pm: Amazing video illustrates why NZTA is telling people to avoid unnecessary travel on SH1 between Christchurch and Oamaru. It shows drivers navigating a treacherous area between Timaru and Oamaru as floodwaters turn the road into river.

Flooding in Pareora in the Timaru district. Source: Supplied

5.10pm: Houses are surrounded by floodwaters in the Timaru district.

4.30pm: Emergency Management Otago has activated and is supporting Waitaki District and Dunedin City to deal with the impacts of heavy rainfall, flooding and strong winds.

Waitaki Civil Defence activated its own emergency operations centre at 3pm.

Group Controller Chris Hawker says at this stage Emergency Management Otago is monitoring and liaising with emergency services along the length of the Otago coast as well as the Otago Regional Council’s hazards team, who are monitoring river levels and modelling how they will react to rainfall.

"We are at a very early stage and we know from the forecast and modelling that there is a lot more rain to come over the next seven hours or so, particularly in Dunedin," Mr Hawker says.

He says many roads are affected by surface flooding, including the state highways along the coast and also inland. Further inland, snow is likely to become a factor as the temperatures drop overnight.

"While many people might have had travel plans this weekend, we would urge everyone to consider the conditions and think twice about hitting the roads tonight."

4.20pm: Timaru is under water.

4.00pm: Civil Defence says the state of emergency declared in the Timaru District this afternoon is due to significant rainfall in low-lying areas leading to surface flooding, with the risk of rising river levels.

River levels are expected to rise significantly over the next few hours. Any residents in flood-prone areas should prepare for evacuation at short notice. If you feel unsafe, evacuate immediately without waiting for notification.

Emergency services will be checking all at-risk areas and working to help evacuate any properties deemed at risk. All directions issued by emergency services personnel must be complied with.

A number of roads in low-lying areas are now closed and non-essential travel should be avoided.

For further information monitor the Timaru District Council website and Facebook page.