Weather: Severe thunderstorms could hit Wellington, Kāpiti

Severe thunderstorms are expected to roll through the Marlborough Sounds and through to Wellington this morning, bringing torrential rain with them.

MetService has issued a red alert – the highest possible level – for the Nelson City and Marlborough region after severe storms were detected on radar near D’Urville Island and Inner Marlborough Sounds.

There is also a severe thunderstorm watch for the Wellington and Kāpiti-Horowhenua districts, between 8am and noon. Heavy rain is expected and thunderstorms are possible.

The storm is likely to bring extremely heavy rain which in turn can cause flash flooding and make driving conditions “extremely hazardous”.

As the rain set in this morning, Mount Victoria Tunnel was closed in both directions due to a crash, but reopened shortly after.

FINAL UPDATE 9:55AM
The Mt Vic tunnel is now OPEN. ^SG https://t.co/0gEV2jiOkK

— Waka Kotahi NZTA Wellington (@WakaKotahiWgtn) May 9, 2023

Due to heavy rain and strong winds, caution is advised across the state highway network. Please slow down and be prepared for surface flooding. Remember to switch on your headlights and increase your following distance. Haumarutia tō haere - Drive safe. ^AP pic.twitter.com/7ylfvO09Wp

— Waka Kotahi NZTA Wellington (@WakaKotahiWgtn) May 9, 2023

A number of roads in Marlborough are already closed this morning after heavy rain last night. Bothams Bend Rd, Omaka Ford, Jacksons Ford and Wairau Bar Rd are all closed and surface flooding is affecting Northbank Rd.

Severe Thunderstorm Warning issued for Wellington Radar Area https://t.co/xQmD0xZ9TY pic.twitter.com/eY70l170d6

— MetService Severe Weather Info (@MetServiceWARN) May 9, 2023

Marlborough District Council is urging drivers to use their headlights and drive to the conditions.

The National Emergency Management Agency advises that people in the line of the storms should take shelter indoors, away from windows. If people are caught outside they should avoid sheltering under trees and move their cars away from trees too.

Here's your early morning Radar map📡

Some thunderstorms and lightning around, which will be in the mix today

Keep a close eye on the forecast at https://t.co/Yjbq0jgaoz pic.twitter.com/QtqU1j0IOf

— MetService (@MetService) May 9, 2023

In New Zealand a thunderstorm will be classed as severe if it is likely to have more than 25mm/h of rain, hail of more than 20mm diameter, winds up to 110km/h and damaging tornadoes.

The storm comes a day after torrential rain caused widespread chaos in Auckland and the upper North Island.

Auckland, Northland and Bay of Plenty were all under heavy and severe weather warnings yesterday as downpours battered the regions, causing surface flooding and commuter chaos.

All weather warnings and watches have been lifted for the North Island but Auckland is still under a local state of emergency, some roads are still closed due to flooding and there is a risk that waterways will continue to rise with periods of heavy rain and thunderstorms still possible.