Coastal Otago faces an orange heavy rain warning until 9am Monday, with 80 to 120 millimetres of rain forecast. MetService says there is a high chance the alert could be upgraded to red.
The most intense rainfall is anticipated from late Sunday afternoon through to early Monday morning. MetService has warned of dangerous driving conditions, possible road closures, flooding and slips in the area, and has urged people to avoid unnecessary travel.
Northern Southland and Otago excluding coastal areas are covered by an orange heavy snow warning from 6am Sunday until 6am Monday. MetService meteorologist Maddy Neal said the region could see substantial snow accumulation at some levels, with up to 1 metre potentially possible above 800 metres.
Snow levels are anticipated to drop during Sunday, potentially reaching as low as 200 metres in some locations and bringing snow to urban centres including parts of Central Otago, northern Southland and possibly Dunedin. Neal said the chance of the orange snow warning being upgraded to red is now moderate.
Road snowfall warnings apply to Haast Pass, Lindis Pass, Crown Range Road and State Highway 1 between Dunedin and Waitati. "We just want to make sure that people are driving to the conditions and thinking about changing their travel plans if they're going to be experiencing disruptions from snow," Neal said.
From Monday afternoon, Marlborough and inland Canterbury north of Lake Sumner will be placed under an orange heavy rain warning from 4pm Monday until 6pm Tuesday, with 50 to 200 millimetres forecast about the ranges and 60 to 90 millimetres nearer the coast. MetService says that warning also has a moderate chance of being upgraded to red.