Heavy rain warning for upper Whanganui region and Taumarunui this weekend

The headwaters of the Whanganui River is expected to get around 70 to 90mm of rain from a north-west flow. Photo / File

Heavy rain is on the horizon for the upper Whanganui region, including the headwaters of the Whanganui River.

From Friday evening to early Saturday morning about 70mm to 90mm of rain, with isolated thunderstorms, is expected in Taumarunui and Tongariro National Park, including the headwaters of the Whanganui River. The warning also covers Waitomo.

Metservice's April Clarke said the rain in the headwaters will be a spillover from a north-west flow but the majority of the rain will be in the north.

Rainfall peak intensities of 10mm to 20mm per hour are expected in thunderstorms.

Anyone travelling for essential travel over the weekend is being urged to take caution when driving in the expected rain conditions. Photo / Bevan Conley

Clarke said places further south, such as Whanganui city, could get a brief period of heavy rain with the thunderstorms.

"People just need to be aware of the forecast and if you're heading out for some supermarket shopping, maybe take a look at the rain radar because you'll be able to see the heavy shower coming your way and could maybe make driving conditions not so great and we don't want accidents."

She said Metservice put heavy rain warnings in place when prolonged rain was expected over a large area.