Thunderstorms and lightning are set to lash western parts of the country, as Aucklanders are warned of strong winds that could disrupt rush hour traffic this afternoon. 

MetService says there is a moderate risk of thunderstorms in areas including Northland, Auckland, northwest Waikato and Coromandel Peninsula this morning. The outlook is valid until midnight. 

Aucklanders up in the early hours of this morning have already been treated to lightning and thundery shows overnight. 

“These thunderstorms may be accompanied by heavy rain with intensities of 10 to 25mm/h and small hail,” MetService said. 

“Strong wind gusts of 70 to 90km/h are also possible with any thunderstorms that occur in the west from Waitomo to the Kāpiti Coast.” 

Motorcycles, trucks advised to avoid Harbour Bridge this afternoon 

The NZ Transport Agency Waka Kotahi said weather authorities had advised there is a chance of wind gusts in Auckland reaching between 75km to 90km/h between 3pm and 7pm - which could affect rush-hour traffic. 

It could also affect traffic on the Harbour Bridge. 

High winds could cause disruption to the Auckland Harbour Bridge this afternoon. Photo / Michael Craig 

“It is likely that speed limits may be reduced and some lanes on the bridge may close if wind gusts reach threshold levels. The bridge may remain in a 4 x 4 formation during the evening peak.” 

Motorists are advised to drive to the conditions and keep an eye on electronic message boards that may show lane closures or reduced speeds. 

Motorcycles, trucks and other high-sided vehicles are advised to avoid the Harbour Bridge completely during this time. 

Auckland is in for a gloomy day on the weather-front; with scattered rain - heavy, at times - and possible thunder. However, that is expected to clear this evening to increase to fine spells. 

Strong northwesterlies in exposed parts are possible until late this afternoon. A temperature high of 18C and overnight low of 12C is forecast. 

There is also a moderate risk of thunderstorms in parts of the South Island - as a front moves up during the day - from Fiordland to the Buller District. 

Again, those thunderstorms may bring some brief heavy rain. 

“This low risk is also mostly associated with the front during the afternoon and evening,” MetService said. 

Road snowfall warnings 

Drivers are advised of road snowfall warnings on Arthurs Pass (State Highway 73), Crown Range Road and Milford Rd (SH94). 

Canterbury is the place to be this morning - with nothing but sunshine expected, apart from the possible odd shower this afternoon or evening. 

Christchurch has a high of 17C today, but an overnight low of 1C will mean extra blankets tonight. 

The remainder of Otago and Southland are also mainly fine. However, a rain is expected this afternoon and early evening.