Marsters said there will be a brief reprieve tomorrow morning from the bad weather before an unsettled week ahead.
A fast-moving front is expected to hit the west coast of both the North and South islands tomorrow afternoon, bringing rain and showers.
Metservice issued a severe thunderstorm watch at 10am today for the Coromandel Peninsula, Waikato and Bay of Plenty areas.
MetService is advising that if these regions are hit with severe thunderstorms, they could see damaging wind gusts of 110 km/h or more, large hail that is 20mm or more in diameter and the possibility of small tornadoes.
Large hail can cause significant damage to crops, orchards, vines, glasshouses, and vehicles, as well as make driving conditions hazardous, says MetService.
Wind gusts greater than 110 km/h in strength can cause some structural damage, including trees and power lines, and may make driving hazardous. If any tornadoes occur, they will only affect very localised areas.
There are scattered showers, some heavy, forecast for Northland, Auckland, Hawke’s Bay, Wairarapa and Manawatu to Wellington, with a chance of hail and thunder this afternoon and evening.
In the South Island, Marlborough and Nelson are expecting rain turning to scattered showers in the late morning, with some heavy showers and thunder forecast inland this afternoon and evening.
In Canterbury, Otago and Southland, cloud and patchy rain are expected to clear towards midday before more potential heavy showers and thunderstorms will hit this afternoon.
Shortly before 6pm last night, MetService weather radar detected severe thunderstorms near Orewa, Puhoi, Whangaparaoa and Silverdale moving towards the south-southeast.
Central Auckland received its first dose of rain around 6.30pm when it was pounded with a short, powerful deluge.
Fire crews responded to more than 50 weather-related incidents from Hatfields Beach to Manukau, including trees that have blown onto houses, trees down across roads, water entering properties, and loose roofing iron.
There were reports of flash flooding as well as hail, thunder and lightning. Some roads became “rivers of water” while a video posted to social media appears to show water pouring through the light fittings at one of the region’s busiest hospitals.
There was also at least one report of a sprinkler having been set off by water coming in through the ceiling, and multiple other alarms that have been set off by the weather.
Savage wind gusts and downpours forced people to take cover in nearby shops.
Social media users also posted videos of the rain seeping through door jambs and also coming through aluminium window frames.