Weather: Snowfall warnings for South Island mountain passes, scattered showers for Auckland

Tāmaki Makaurau Auckland should expect a mostly cloudy day with isolated showers. Photo / Brett Phibbs

MetService has issued road snowfall warnings for several mountain passes in the South Island, Te Waipounamu, and across the central plateau of the North Island, Te Ika a Maui.

Waka Kotahi said snow chains were essential for vehicles using Arthur's Pass SH73 to Otira. The transport agency said towing wasn't allowed, and that motorists should allow extra time.

Scattered rain could fall around the country today, but it should clear for most centres by the afternoon.

Tāmaki Makaurau Auckland should expect a mostly cloudy day with isolated showers until the afternoon, and the central North Island may see snow throughout the day.

Snow flurries could leave up to 1cm of snow on Napier-Taupō Rd SH5 and Desert Rd SH1.

Road Snowfall Warnings issued for Aotearoa/New Zealand.

Full details at https://t.co/aIkbAI2pg0 pic.twitter.com/3Hpvj4N0R6

— MetService (@MetService) September 12, 2022

Metservice meteorologist Alwyn Bakker said a trough of low pressure moving eastward across Aotearoa was causing the rain and snow.

"At higher levels of the atmosphere, particularly cold air will be making its way over Te Waipounamu.

"The cooling effect will be less noticeable at ground level, but the resulting atmospheric instability makes thunderstorms more likely, and snow is expected to 300-400m in the south," he said.

As much as 6cm of snow was forecast to fall and settle at higher elevations about the Southern Alps, Kā Tiritiri o te Moana. Road snowfall warnings were issued for the Lewis Pass SH7, Arthurs Pass SH73, Porters Pass SH73, and Lindis Pass SH8.

Given the ❄❄❄ in Te Waipounamu/South Island, how would you say it's snowing?

Kei te pūhuka!

More on our website https://t.co/30C77rloYZ pic.twitter.com/JVO6Y8FvuH

— MetService (@MetService) September 13, 2022

Snow was also forecast to settle as low as 200m on the Haast Pass SH6, Crown Range Rd and Dunedin to Waitai Highway SH1.

A strong and unstable westerly flow is causing unsettled weather across the country this week, bringing snow and bands of rain to many regions.

"At this stage, the exact position of the low centre is uncertain, so as we progress through the week MetService advises keeping up to date with the latest forecasts," states Bakker.

Frosty conditions will continue to put a damper on spring for southern and central parts of the North Island this week, dusting Mt Taranaki with a layer of snow.