Kāpiti Coast District Council says that up to four houses in Waikanae and eight in Paraparaumu were damaged by the strong winds.
Fire and Emergency’s Lynn Crosson said 12 cars were also damaged by falling trees and debris.
One person received minor injuries when the vehicle they were in was struck.
Paraparaumu resident Joss Hicks, whose house was damaged, feared she may have to leave her home tonight.
She was walking her dog at the time the area was hit but returned home to find her roof tiles had partly lifted, she said.
A business owner in Waikanae said four trees went through roofs of neighbouring buildings.
But Mower Shop owner Matt said his store escaped with two small holes in the roof.
The windows of his colleague’s car were broken, he said.
MetService duty forecaster Karl Loots said it was too early to say whether a tornado hit the area.
He said it was possible given the severe thunderstorms which just moved through the area.
A spokesperson for Kāpiti District Council said they had crews out assessing the damage.
Lightning strike cuts power
About 12.30pm lightning led to a brief power outage in many parts of Wellington including Brooklyn, Island Bay, Hataitai and central city.
It knocked out traffic lights on The Terrace in central Wellington and the RNZ offices also experienced a power outage.
Wellington Regional Hospital has been running on generators since the power outage hit.
A spokesperson for Capital and Coast District Health Board said the generators were activated and there was no disruption to patient care.
However, the hospital would continue to use its generators until it was sure the problem with the main supply would not occur again, they said.
The heavy rain has flooded part of Stuff’s offices.
Water poured through the light fittings and pooled on the floor in a tower block in central Wellington this afternoon after storm-water systems become overwhelmed by torrential rain.
It is the second time this year that the 18-storey Fujitsu Tower on Lambton Quay has flooded.
Rebecca Holmes, who worked for the company which owned the complex, said she was alerted by tenants to the water but expected it would not take long to stop the water once the blockage was found.
An RNZ reporter at Wellington Airport said it lost power temporarily and the check-in line increased because the baggage carousel would not turn back on.
Transpower are inspecting their lines after lightning strikes hit the Wellington region, causing power outages.
A spokesperson said multiple circuits had been impacted.
When the lightning hit it caused a momentary voltage dip, which can cause outages, the spokesperson said.
Supply to the region is now back, but Transpower said it was still gathering information and working out what had happened to the circuits.
Wellington Electricity said there was a power outage in the Maidstone area of Upper Hutt, affecting about 400 people, but it was still unclear if that was connected to the storm.
Metlink said commuters could expect delays to bus services this afternoon due to poor weather conditions and potential surface flooding across the Wellington region.
Trains were currently suspended on the Johnsonville Line due to the weather but bus replacements were being organised, Metlink said.
Wellington Region Emergency Management is warning coastal residents in Porirua and Kāpiti to prepare sandbags and shift their cars ahead of a heavy swell warning from midnight tonight.
Kāpiti Coast District Council and Porirua City Council have teams on standby to monitor and help with any impacts of the heavy swells.
Elsewhere, thunderstorms are expected to affect western parts of the North Island from Waikato southwards until evening, bringing localised heavy rain, hail and squally wind gusts, MetService warned.
There was a risk that a few of the thunderstorms could be severe south of Raglan between 8am and 2pm, with damaging wind gusts in excess of 110 km/h, and one or two small or damaging tornadoes, the forecaster said.
Areas likely to be affected are Waitomo, Taranaki, Wanganui, Manawatū, Kāpiti-Horowhenua, Wairarapa and Wellington.
Some of the thunderstorms could bring localised downpours with intensities of 25 to 40 mm/h possible.
The Wellington region has been hit by thunder, lightning and bursts of heavy rain from the early hours of the morning.
Porirua was hit hard overnight, and the council said a bridge on Belmont Road was compromised after the rain.
The council would also be looking to close Grays Road in Pāuatahanui as the high tide approaches, because it is expected the area would end up under water.
There was severe surface flooding on Champion Street, though the water had later cleared.
Tara Higgs, who lives on Champion Street, said she and her husband spent two hours trying to unblock drains in waist-high water, and calls for help to Porirua City Council went unanswered.
Higgs said the water was a mix of rain water and sewage and posed a health hazard. The council has been approached for comment.
MetService forecaster Karl Loots told Morning Report a series of thunderstorms had hit the region one after another, and were particularly severe in terms of rainfall rates. These were in access of 50mm/h and accounted for significant flooding this morning.
He said more storm fronts were expected in the Wellington region this morning before moving northeast, with possible tornados developing anywhere between New Plymouth and south Waikato.
“What we’ll see with these thunderstorms is one or two of them could become severe,” he said.
“They’re embedded in a very intense north-west flow and moving in access of 100km/h. So not only do we have a really heavy rain potential from them, they’re also quiet squally, and there’s a possibility of one or two tornados too.”
Loots said the main effect of these storms would be wind damage, with wind gusts expected to be in excess of 110km/h.
These poses a risk to drivers, particular those driving high-sided vehicles and motorcycles.
The extremity of the wild weather will then lessen the further north these travelled past southern Waikato,” Loots added.
People in the areas affected are advised to keep up to date with weather warnings during the day.
In the Hutt Valley, residents on Murphy’s Road were cut off by multiple slips blocking the road.
In Stokes Valley, Lower Hutt, two cars had been stuck in floodwaters and two roundabouts were inundated with water.
Mana Esplanade in Paramata was also closed for a time due to flooding, and has since been reopened.
Hayward Hills road in the Hutt Valley and Newlands Road were closed due to surface flooding.
A thunderstorm watch was in place for Nelson, Buller and Westland until 10am