Heavy rain is drenching the lower North Island as a front moves up the country, giving the upper South Island a chance to dry out.
A deluge flooded roads and affected homes yesterday, forcing some Nelson homeowners to sandbag their properties.
Westport was isolated because of severe flooding on State Highway 67 from Westport to Greymouth, State Highway 6 from Westport to Inangahua, and on State Highway 67 from Westport to Karamea.
But South Islanders can expect some relief from the rain over the next few days as the wet weather moves north, said MetService forecaster Heath Gullery.
However, a warning is now in place for the lower North Island.
The front would move slowly eastwards today, to lie just east of the Bay of Plenty tonight.
Heavy rain was forecast to bring 250mm of rain for Mount Taranaki, and 130 to 180mm of rain for the Tararua Ranges.
It should ease later today.
Central police communications spokesman Bruce Mackay said police were on their way to Inglewood where a woman was trapped in her car after driving through deep water.
Other vehicles were able to pass through the flooding, but she had got stuck, he said.
A fire service spokesman said they had not had any weather related calls this morning, but they were expecting it to pick up as the morning wore on.
By tomorrow, weather in most parts the country would improve, Mr Gullery said.
"A ridge of high pressure is moving in, so there will be fairly settled weather around much of the country. However, cooler southerlies are coming in so it will be a little bit cooler."
Earlier on Sunday there was concern that the Buller River was close to breaking its banks, and water levels were high around Murchison, Golden Bay and Nelson. These had all receded as rainfall dropped off.
State Highway 65 south of Murchison from O'Sullivan Bridge to Springs Junction remained closed this morning due to flooding.
It will remain closed until at least 3pm today, when conditions will be reassessed.
In Nelson, Avon Terrace from Bridge St to Hardy St is now open, as is State Highway 6 from Inangahua to Westport and from Rai Valley to Renwick.
Police and fire services said they had not received any major weather-related callouts this morning.
