A developing and deepening low in the Southern Ocean could bring several days of unsettled weather to New Zealand predict WeatherWatch.co.nz forecasters.

The low is expected to move out of the Southern Ocean this weekend, cross the country early next week and lie east of the country early to mid next week. 

Head weather analyst Philip Duncan says its size means it wont be an overnight system.  “With large lows like this incoming one we may find certain features of the weather only last a day or so, such as a day of rain or a day with thundery showers, but from the start of this low moving in to the day it finally departs it’s likely to affect the country for five days at least”.

The low will see warm nor’westers building over the South Island and lower North Island this weekend with heavy rain pushing into the West Coast later on Saturday then the North Island on Sunday and Monday before turning to showers.

Across Monday and Tuesday the low will transition from being in the Tasman Sea to lie east of New Zealand.  “At this stage it may deepen again early next week but more importantly this is when the southerly tail moves in”.

WeatherWatch.co.nz says it’s still too early to know how much snow will fall but at this stage it doesn’t appear to be a sea level event.  “In Southland, for example, we expect single digit highs for some centres on Tuesday and Wednesday and the wind chill will certainly be noticeable, but at this stage we’re saying snow is on the way for the ski fields and some farms to about 300 metres”.

Mr Duncan says WeatherWatch.co.nz hasn’t ruled out the chance of snow falling in Queenstown on Tuesday or Wednesday.

“Overall while this low looks large it may not cause too many serious problems for New Zealanders, but will affect the entire country in various ways, either through rain, thunder, gales, snow, and in a few isolated cases, all of the above”.

WeatherWatch.co.nz adds that as the low moves through and the wind directions change, some regions may be sheltered from unsettled weather altogether, meaning sunny weather will also be in the mix.

– WeatherWatch.co.nz

SATURDAY MORNING – deep low and incoming front  lie off the South Island’s SW coast

SUNDAY MORNING – The rain moves into the North Island, winds build in most places to become blustery.  Damaging gusts are expected to be isolated.

MONDAY MORNING – Rain and winds spread further over the North Island but winds ease over the South Island as the low moves up the West Coast and a new centre forms on the east coast.

WEDNESDAY – The low is to the east and a southerly flow comes in behind it – not looking too aggressive at this stage.

TUESDAY NIGHT – The wind flow and direction shows the low to the east a a strong SW wind up the eastern coastlines and about Auckland and the upper North Island.

All maps courtesy of Weathermap.co.nz