Red alert! Storm forecast more dire

MetService upgraded today's severe weather alert to a red warning along the east coast, expanded the area of the advisory to include Marlborough Sounds and increased the timeframe to run through early Wednesday.

Most of Marlborough and north Canterbury remains under an orange heavy rain warning, but a coastal and mountain swath from Ward past Kaikoura is under a red warning.

The warning period is 35 hours, from 6pm today until 3am on Wednesday.

MetService projects 200-250mm of rain, with 60-100mm "likely in areas near the coast", and peak rates of 15-25mm/hr through Tuesday afternoon, "especially about the ranges".

The agency also advises: "Do not enter floodwaters and avoid unnecessary travel. Be ready for communication and power outages. Be prepared to self-evacuate if you see rising water."

Check Weather Warnings & Watches | MetService for updates.