A Heavy Rain Watch is in place for Bay of Plenty, including Rotorua, and Waikato.

MetService says this watch is valid until 6am Tuesday December 26.

Periods of heavy rain are forecast for the region, and amounts may approach warning criteria. Thunderstorms are likely.

Rain with thunderstorms is expected to develop this afternoon over northern regions of the country.

A severe thunderstorm watch is in place for Northland, Auckland, Coromandel Peninsula, Waikato, Waitomo, Taumarunui, Bay of Plenty, Rotorua, Taupo, and Taihape. This is valid until 10pm Monday, December 25.

A deeply moist northerly flow affects the upper North Island today. Periods of heavy rain and thunderstorms are likely. These thunderstorms may become severe bringing localised rainfall rates of 25 to 40 mm per hour.

Rainfall of this intensity can cause surface and/or flash flooding, especially about low-lying areas such as streams, rivers or narrow valleys, and may also lead to slips.

Downpours are expected with the thunderstorms this afternoon and evening, and a Severe Thunderstorm Watch has been issued with respect to this.

"However, heavy rain could continue in Bay of Plenty, including Rotorua, and Waikato overnight Monday and into Tuesday morning, and this possibility is covered by this broadscale watch for heavy rain," says a MetService spokesperson.

Wednesday December 27 2023
A weak ridge of high pressure should bring more settled weather to most of New Zealand on Wednesday. While afternoon showers are likely in some inland places, at this stage there is minimal risk of severe weather.

Thursday December 28 2023
Moist northerlies should again develop over the country on Thursday, but at this stage there is minimal risk of severe weather.

Friday December 29 2023
The moist north to northwest flow should push across New Zealand on Friday, bringing rain and strong winds to many places. There is low confidence of rainfall meeting warning criteria over western and central parts from Fiordland to Coromandel Peninsula and East Cape, but moderate confidence over northern Fiordland and Westland, and western areas of the North Island from the Tararua Range to Taranaki and Taupo, as indicated on the chart.
There is also low confidence of severe northwest gales from Fiordland over eastern parts of the South Island to the lower North Island.

Saturday December 30 2023
The strong northwest flow continues to bring rain and strong to gale northwesterlies to many areas on Saturday. There is low confidence of significant rainfall from Fiordland to Coromandel Peninsula and East Cape, but moderate confidence over northern Fiordland and Westland. There is also low confidence of severe west to northwest gales from Fiordland to Hawke's Bay, as indicated on the chart.