After some high temperatures across Aotearoa New Zealand, MetService is forecasting cooler conditions to start the weekend in the wake of a southerly change.

Rain and wind affect the South Island today (Thursday) as a cold front moves north over the island through this afternoon and evening. 

Northwesterly winds strengthen ahead of the front before they switch to cold southerlies, with a Strong Wind Watch in force for Otago and Southland until 7pm this evening. 

MetService meteorologist Ngaire Wotherspoon says the moist northwesterly flow over the Southern Alps is a classic setup for the foehn effect.

“Where rain on one side of the mountain means warmer and drier winds on the leeward (other) side. We’re already seeing hot, windy conditions in the east, while in the west there is heavier rainfall with a Heavy Rain Watch in place for Fiordland,” she says.

Temperatures made it to the high 20s in Canterbury and Otago, but the southerly change passing through this afternoon and evening, as well as a sprinkling of rain, will mark significant drop in temperatures for both regions. 

Ōamaru may struggle to reach the mid-teens on Friday, with a high of only 15°C forecast.

The front moves on to the North Island early tomorrow, spreading a band of scattered rain and cooler temperatures as far north as Rotorua before stalling, Ngaire says.

“Rain from this weakened front sticks around over the North Island for the weekend, clearing on Sunday night. Down south the weekend is looking sunnier, with temperatures starting to warm up again on Sunday as we head into summer.”