A heavy snow warning has been issued in the South Island with MetService saying the snow "may disrupt travel".
A slow-moving front is moving up the southern half of the South Island this weekend, bringing widespread rain and inland snow.
MetService says a heavy snow warning is in place for inland Canterbury south of the Rangitata River, with 15-20cm of snow expected above 500 metres.
Southland, Otago and South Canterbury also have heavy snow warnings, while a heavy rain watch is in force for the Westland Ranges.
"Heavy snow could disrupt travel plans, damage trees and powerlines in the area, and cold conditions may cause stress to livestock," it warned on Facebook.
Photos show snow already starting to pile up on high-altitude roads in the South Island, including one from Gorge Hill in Southland.
Weather watches and warnings
Heavy Snow Warning - Orange
Impact: Heavy snow may disrupt travel in affected areas and could damage trees and powerlines. Cold conditions may cause stress for livestock.
Area: Inland Canterbury south of the Rangitata River, including the Mackenzie Basin
Period: 16hrs from 5pm Sat, 18 May - 9am Sun, 19 May
Forecast: Expect 15 to 20 cm of snow to settle above 500 metres, with lesser amounts further down.
Heavy Rain Watch
Area: Ranges of Westland District about and north Mt Ward
Period: 24hrs from noon Sat, 18 May - noon Sun, 19 May
Forecast: Periods of heavy rain, and amounts may approach warning criteria. Note, this Watch may be extended into Sunday afternoon or evening.
Heavy Snow Watch
Area: Queenstown Lakes, and Central Otago
Period: 10hrs from 11am - 9pm Sat, 18 May
Forecast: Snow lowering to 400 metres, with heavy falls possible above 500 metres where amounts may approach, or even exceed warning criteria in localised areas. Snowfall is expected to ease from the south during the afternoon and evening.
Area: Southland north of Lumsden and west of S.H 90, and Fiordland about and north of Lake Manapouri.
Period: 2hrs from 11am - 1pm Sat, 18 May
Forecast: Snow lowering to 300 metres, with heavy falls possible above 500 metres where snowfall amounts may approach warning criteria.
Road snowfall warnings
Area: Porters Pass (SH73)
Period: 8hrs from 9pm Sat, 18 May - 5am Sun, 19 May
Forecast: 1 - 2 cm of snow could accumulate near the summit with lesser amounts to 900 metres.
Area: Haast Pass (SH6)
Period: 6hrs from 5pm - 11pm Sat, 18 May
Forecast: 2 - 4 cm of snow could accumulate on the road south of the summit.
Area: Lindis Pass (SH8)
Period: 14hrs from 2pm Sat, 18 May - 4am Sun, 19 May
Forecast: 8 - 15 cm of snow could accumulate near the summit with lesser amounts to 400 metres.
Area: Crown Range Road
Period: 4hrs from 11am - 3pm Sat, 18 May
Forecast: 3 - 5 cm of snow could accumulate near the summit with lesser amounts to 400 metres.
Area: Milford Road (SH94)
Period: 3hrs from 11am - 2pm Sat, 18 May
Forecast: 3 - 5 cm of snow could accumulate above 700 metres, with lesser amounts to 400 metres.
