A weather bomb has exploded across Hawke's Bay with wild winds, lashing rain and snow to low levels causing road closures, power outages, slips and uprooted trees.

Weatherwatch.co.nz said earlier tonight that there will be no immediate letting up of the intense blizzard across the Hawke's Bay ranges tonight.

The heavy rain in many places between Napier and Wairoa, and towards Gisborne overnight, will continue across a big part of Sunday.

Roads are closed and more flooding is possible overnight as a low pressure system (currently centred over the upper North Island) continues to deepen and fuel a very wet easterly flow into Hawke's Bay and central eastern parts of the North Island. At the same time the Antarctic blast is crashing into it from the south - creating an especially heavy area of snow.


Snow and flooding has closed major highways in the central and eastern North Island along with major power cuts.

NZTA has announced SH5 from Napier to Taupo will remain CLOSED overnight due to Heavy Snow. WeatherWatch.co.nz says it's likely to remain closed, or affected by snow and ice, across much or most of Sunday based on the current forecast.

Also, SH2 the Napier to Wairoa highway is CLOSED due to Heavy Rain and flooding - and with more heavy rain all night flooding will intensify.

Meanwhile Unison teams are working to restore electricity to all areas.

For customers in the Taupo Plains, Transpower and Unison advise they will try and fly the lines tomorrow if weather permits.

"Helicopters are ready on standby," said Unison Relationship Manager, Danny Gough.

"Weather indicates more snow and wind overnight. Lightning is showing on the radar coming in from the east coast going across Napier to the Wairoa area, so we continue to advise customers to be prepared for outages as this horrible weather continues."

He advised customers in Rotorua and Taupo should also prepare for power outages as the weather moves up across the country.

"Already, small pockets of customers in rural parts of Rotoma and Reporoa in Rotorua are experiencing no power. We appreciate everyone's patience as Mother Nature rips across our network regions."

This morning Metservice issued a severe weather warning for the region, as a low pressure system over the North Island was expected to bring significant heavy snow and blizzard conditions for inland Hawkes Bay, eastern Taihape, and the eastern ranges of Taupo, today and overnight.

So far today, snow has fallen to as low as 300 metres, with another 50 to 80cm of snow expected top accumulate above 700 metres on top of what has already fallen before tomorrow morning, Metservice reported.

Around 40 to 60cm of snow could accumulate above 500 metres, and lesser amounts of snow were expected down to 300 metres.

Metservice meteorologist Peter Little said "Hawke's Bay is getting the worst of it in terms of rain".

While it was cold around most of the North Island, Mr Little said a frontal system north of the region meant it was being doused in rainfall, with heavy rain beginning around 5PM last night.

Heavy rain was expected to drench lower lying parts of Hawkes Bay today, with around 151mm of rain falling at Te Pohue in the past 24 hours.

There has been 97mm in Hastings CBD and 78mm in Napier.

Another 80 to 100mm of rain was expected on top of what has already fallen, but the rain was expected to ease overnight.

Mr Little said the rainfall had been "quite steady", but the heaviest period was the hour to 4AM this morning.

The wind had also picked up, reaching 78km/h at Napier airport, and gusting to 117km/h at Cape Kidnappers around 11am this morning.

Earlier Mr Gough said they were working hard to restore power to all affected customers.

There had been two major events which caused power outages across the region this morning, at 3.30AM, then just after 10AM.

"Hawke's Bay went out basically twice this morning," he said.

The heavy snowfall had affected the Transpower transmission line from Wairakei GXP, the main power supply coming into Hawke's Bay, leaving homes and businesses across the region without power.

As of early this afternoon, the Unison website reported there were 25 unplanned outages in Hastings, and 22 in Napier, however Mr Gough said these numbers were "dynamic", and Unison staff were working to get power back to affected customers.

"It's been an eventful day, but we're doing all we can and working very hard, given the current weather and safety concerns," he said.

As it was "highly likely" there would be more outages as the severe weather continued, Mr Gough said people needed to be prepared for further events.

"Stay warm, and have a contingency plan in place. Stay indoors if possible, and treat all power lines as live."

The weather has also closed roads around the region, including Breakwater Road, Napier, which was closed this afternoon between Hardinge Road and Marine Parade due to a slip.

Earlier today the New Zealand Transport agency reported SH5 from Napier to Taupo was also closed, and Metservice issued a snowfall road warning with further snow expected today and overnight.

Police reported State Highway 2 between Napier and Wairoa has been closed due to weather conditions in the area. At this stage it is not known when the road will reopen.

Metservice also advised snow was expected on SH1, Desert Road, road today and overnight, where 10 to 15cm of snow could accumulate.

The weather bomb has hit sporting fixtures in the Bay, prompting cancellations of predominantly junior matches by last night.

Hawke's Bay Rugby Union officials cancelled all junior matches in Napier, Hastings and Wairoa today. That doesn't include secondary schools' rugby.

Central Football yesterday cancelled all junior games but stated on their website that all seniors games were still on schedule.

Hawke's Bay Netball operations manager Tina Arlidge said today's secondary and primary games had been called off but they were going to make a decision on club matches this morning.

A leak above a court at the Pettigrew-Green Arena, Taradale, last night prompted the cancellation of the 5th/6th playoff matches between Central Sports Vet Services HB and Havelock North Jazz Apples Kauri in the premier club Super 6 playoffs.

Fortunately, the severe weather had not caused havoc for emergency services so far.

Senior Sergeant Neil Saunders of the police Eastern District command centre said there had been a few road closures, but police had not received any serious call outs this morning.

His advised people, "if you don't have to go out, don't. Stay at home until the weather passes."

Hastings fire senior station officer Mike Peachey said they had responded to minor floodings, and a few leaky roofs, but nothing serious.

The Napier fire service had responded to a call out at Princess Alexandra Retirement Village where some people had been trapped in an elevator, however they were freed shortly after the service arrived.

Napier Station officer Craig Parsons said there had been some fallen trees in Taradale, but "so far we've been quite lucky".

The Waipukurau fire service reported no call outs.

Metservice forecast a low of 6C overnight tonight, followed with more rain tomorrow, which was expected to ease to showers in the morning or early afternoon, then clearing inland in the evening.

Snow would fall down to 400 metres at first, with heavy falls about the Wairoa District. Strong southerlies would gradually ease, with a high of 11C and low overnight of 1C.​