A commuter on Auckland's Harbour Bridge says hundreds of cars were still gridlocked shortly before 8.30pm.

They said NZ Transport Agency had sent out a message that the Harbour Bridge had closed, but shortly after it was reopened again.

"[There was a sign] only once we were already committed with no turn offs.  Had to sit there until it reopened."

Crews are working hard in challenging conditions to safely restore power, Vector said in a statement.

“Where we’re able to find the damage and determine how long it’ll take to fix it, we’ll let customers know, either directly by email and text, or by updates to our outage centre. In other cases we may not be able complete damage assessments and repair plans until morning.

“We can’t provide exact numbers of homes without power as they are constantly changing, due to the ongoing weather causing vegetation to impact the network, and as our crews are assessing damage and restoring power where possible.

“Outages are spread around the region. Crews will continue to work and rotate through the night, but will stand down if it is unsafe for them. We have as many crews working on this as possible, including extras we’ve temporarily redeployed from planned capital works.”

34 Air New Zealand regional services and six domestic jet services have been cancelled due to today’s weather, Chief Operating Officer Alex Marren said. 

“Unfortunately, severe weather, including high winds, hail and thunderstorms has impacted our operations across the country.

“Our Auckland services were temporarily paused four times today when gusting wind conditions meant it was not safe to operate at Auckland Airport. Three of our regional aircraft experienced lightning strikes earlier today and have been inspected by our engineering teams and are safe to return to service.

“Our teams are working round the clock to rebook impacted customers on the next available service to get them to their destinations. We appreciate changes to travel plans are frustrating and would like to thank customers for their patience and understanding while we work through this weather disruption.”

 Fire and Emergency NZ (Fenz) said they have responded to a "steady number" of weather-related call outs in Auckland since about 10am.

Crews had attended over 150 events from 9.30am to 8pm on Wednesday. 

At 8pm, there were 31 active events that Fenz were attending.

The majority of these calls have been for trees falling on houses and cars and snapped powerlines.

An Auckland Airport spokesperson said an alert that wind was exceeding 35 knots was issued to airlines at 3.35pm and remained in place at 7.30pm. 

"These alerts are made in the interests of safety operations on the ground and operational decisions are at the discretion of airlines and ground handlers. 

"Some arriving and departing flights may be impacted by weather, so we ask travellers to keep an eye out for messages from airlines about the status of their flight." 

Travellers were urged to contact airlines directly for information about flight delays or cancellations. 

"The safety of the airfield and the safe movement of aircraft is always our priority," the spokesperson said.

Snowfall has closed part of the Desert Road in the central North Island.

Traffic in Auckland's CBD is gridlocked this evening.

Cars were at a virtual standstill where the Herald walked, with traffic backing up along Victoria St, Nelson St, Fanshawe St and Halsey St.

Photos / Raphael Franks

A severe thunderstorm watch over Auckland, Great Barrier Island, Coromandel Peninsula and Waikato has been extended until 9pm tonight.