The power is out, trees and sheds are on fire and more than 100 lightning strikes have been recorded in the Hutt Valley and Kapiti Coast in the past two hours, according to media reports.
New Zealanders are being warned to brace for the storm, which the New Zealand Herald described as "one of the biggest storms on the planet".
The worst of the storm has hit on the West Coast and Southern Alps where heavy rain is falling, with snow down to 200 metres in places.
Visit the New Zealand Transport agency for updates on road conditions.
Tasman Storm Sparks Concerns
Later this afternoon a storm front is expected to hit entire the North Island.
Heavy rain and winds of up to 130km/h are expected.
The wild weather is expected to bring extreme conditions over the next 48 hours.
New Zealanders are being warned to stay away from the beaches as the storm hits