Heavy rain forecast for Northland

A low pressure system is likely to being heavy rain to Northland tomorrow and Thursday. Photo / John Stone

While Northland is likely to escape the wrath of Tropical Cyclone Cook this week, heavy rain is forecast for most of the region tomorrow and on Thursday.

MetService has issued a severe weather watch for the west of the South Island and parts of the North Island, including Bay of Plenty, as a result of two different weather systems.

Meteorologist Claire Flynn said a northeasterly air flow ahead of a low pressure system in the Tasman Sea was causing very humid, sub-tropical air to be dragged down over the country.

The system, she said, would bring heavy rain to the west of the South Island today before moving to Northland tomorrow morning.

"For Northland, there will be a few showers early on Wednesday which will develop into heavy rain. Thursday will be another wet day but rain will ease off from Friday.

"We don't have a severe weather watch for Northland at this stage and computer models show areas like the Bay of Plenty are likely to bear the brunt of this low pressure system," Ms Flynn said.

She said unsettled weather with intermittent showers was forecast for Northland during Easter weekend.

The other weather system is Tropical Cyclone Cook which was a category 3 cyclone near New Caledonia yesterday morning and is expected to pass near East Cape on Thursday evening.

Regardless of how close the cyclone came to New Zealand, she said heavy rain was still expected in Northland tomorrow and on Thursday due to the sub tropical air from the Tasman.

Ms Flynn said temperatures would be in the mid 20s during the day and 19C overnight today, tomorrow and on Thursday because of the humid, sub tropical air.

Day time humidity level would be between 75 per cent and 80 per cent and close to 100 per cent overnight.

She is advising those planning on travelling for the Easter weekend or are involved in outdoor events to keep up to date with MetService severe weather watches and warnings, and to keep an eye on road conditions through nzta.govt.nz/traffic.