Severe thunderstorms lash Auckland region bringing downpours, power cuts, travel disruption

Flash flooding and slips could hit parts of Auckland and Northland today, with intense downpours of up to 40mm an hour possible.

Auckland Emergency Management last night warned of flooding in low-lying areas as unsettled weather threatens the upper North Island.

Earlier, MetService issued a severe thunderstorm watch for Auckland and Northland from noon until 9pm, with a moderate risk of severe thunderstorms bringing hazardous driving conditions, surface flooding and poor visibility.

Another thunderstorm watch is in place from midnight until 11am tomorrow for Northland, Auckland, Great Barrier Island, Coromandel Peninsula, Waikato, Waitomo, Taumarunui, Bay of Plenty, Rotorua, Taupō and Taranaki.

This morning, MetService said a “nest of lightning” was detected over the ocean northwest of Northland.

The thunderstorm threat extends beyond the watch areas, with a moderate risk of thunderstorms bringing heavy rain of 10 to 25mm an hour from Northland through to parts of Hawke’s Bay this afternoon and evening.

The heightened thunderstorm risk comes as warm, moisture-laden tropical air sweeps across the country before tomorrow’s election day.

A complex trough of low pressure is expected to move slowly eastwards across New Zealand tomorrow, bringing periods of northerly rain to the central and upper North Island, “along with possible thunderstorms and localised downpours”, according to the MetService’s severe weather outlook.

MetService meteorologist Alanna Burrows said the risk of thunderstorms would increase today and “further increase on Saturday”, as voters head to the polls.

“With rain and the risk of thunderstorms over the next few days, it’s worth keeping an eye on our rain radar and latest forecasts if you’re heading out to vote.”

The unsettled conditions could extend into parts of the South Island over the weekend, Burrows said.

El Niño continues to make its presence felt in Northland, with the region experiencing widespread “meteorological drought” conditions.

Northland Regional Council monitoring manager Jason Donaghy said the region’s average rainfall for October was 32mm, about 36% of the usual monthly total.

“Most groundwater levels are ‘below normal’ to ‘extremely low’ for most of the region for this time of year.”

MetService meteorologist Lewis Ferris said the forecast rain was unlikely to provide significant relief given how dry the region had become.

“There’s some rain around, but it’s not really going to be meaningful rain for that sort of soil mush in the ground. They might have a little bit more luck through Friday and Saturday, but they’re not big rainmakers.”