After a brief lull, MetService is forecasting unsettled weather to return for the end of this week.

A band of heavy rain will make its way onto the South Island today, mainly affecting the West Coast and Southern Alps.

Orange Heavy Rain Warnings are in place for the Westland and Buller districts, starting today (Thursday) in the late afternoon in Westland, then tomorrow morning in Buller.

Heavy Rain Watches have been issued for northern Fiordland, the Grey District, northwest Tasman, and the Richmond/Bryant Ranges.

It isn’t just the West Coast; a significant amount of rain will also fall along the eastern edge of the Main Divide of the Southern Alps, increasing the flow of water into Canterbury rivers and lakes.

An Orange Heavy Rain Warning is in place for these headwaters from this evening.

Strong northwesterly winds will affect exposed parts of Southland, areas directly east of the Southern Alps, and Wellington, where Watches are in place. These winds will pick up as the band of rain to the west draws near.

The rain band will reach the North Island on Friday night. High rainfall amounts are more likely in mountainous areas as the rain crosses over on Saturday, and Heavy Rain Watches have been issued for Mt Taranaki and the Tararua Range.

“Westerly winds and weather systems coming from the Tasman Sea are characteristic of early spring, which is getting close now," says Metservice meteorologist Dan Corrigan.

"It is likely that Aotearoa New Zealand will see more of this kind of weather pattern over the coming weeks, bringing the quick-changing weather we associate with spring.

“Temperatures are also expected to be warmer in contrast to the chilly weather we’ve been having lately.

"Notably, South Islanders will have a break from overnight frosts for the next week, and North Island temperatures on Friday night will likely remain in the double digits.”

MetService is responsible for issuing Volcanic Ash Advisories for the aviation sector (a collaboration with GNS Science and Airways New Zealand).

Volcanic ash from minor ongoing eruptive activity on Whakaari/White Island is drifting over eastern Bay of Plenty today.

GNS Science have indicated that ash fall is only occurring near the island. That is only in the vicinity of the island far away from the shores of the Bay of Plenty. 

Drifting ash higher up in the atmosphere still poses a hazard to aircraft. Information on any current Volcanic Ash Advisories for aviation is available here, and the latest Volcanic Alert Bulletins from GNS Science can be found here.