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weather warning for the region was issued earlier this afternoon, alerting residents to a high chance of severe thunderstorms near Otane and Pakipaki, among several other spots.
The storms were moving towards the northwest, the warning said. They were expected to lie near Hastings early this afternoon before moving towards Waimarama and Havelock North later in the day.
There was also a warning issued for Northland, which was expected to see bouts of similarly chaotic weather.
Metservice was warning the extreme weather could cause surface or flash flooding about streams and gullies, and make driving conditions very dangerous.
Many other spots around the North Island had been placed on a watch for thunderstorms as well as very heavy rain.
Waikato and the Bay of Plenty were being warned of tumultuous weather as was Taihape, Taupo and the Manawatu.
The watch extended to the Auckland region, where it was valid until 8pm.
The warning follows a morning of torrential rain and flooding further up the island, on Auckland's North Shore.
Motorists were stranded in swamped vehicles and more than a dozen homes were awash after a storm cell unleashed a torrent of rain.
Roads turned to rivers and spilled into businesses and homes.
Two motorists required rescuing from their vehicles after they became submerged in the waist-deep floodwater.
A section of Caribbean Drive was closed and lanes on the Upper Harbour Highway were blocked by the quickly rising floodwaters.
Niwa said an incredible 62.4mm of rain fell between 8am and 9am - the wettest hour in at least eight years - as the slow-moving storm cell delivered a deluge over the northern suburb.
Floodwaters started to abate about an hour after the deluge began, but MetService warned it was just a foretaste of things to come today.
Forecaster Tom Adams said much of the North Island remained under a thunderstorm watch until at least 8pm.
