MetService has put the Gisborne/Tairāwhiti region on orange alert for heavy rain overnight Sunday and into Monday morning.

Tonight and Monday, a humid east to northeast flow is expected to affect Gisborne/Tairāwhiti, threatening to bring a period of heavy rain to the region where a warning and watch are in force.

A warning is a more severe concern as people need to be prepared and take action as appropriate as there could be some disruption to their movements and potential risk to people, animals and property. A watch alert is to monitor channels in case the situation was raised to a warning.

MetService said an active trough is also forecast to move across the Westland and Grey districts, bringing a period of heavy rain there with localised thunderstorms and downpours possible. A watch is now in force for those West Coast districts.

Severe thunderstorms were also forecast for the east and lower North Island until 9pm tonight.

Heavy Rain Warning – Orange

For Gisborne/Tairāwhitiabout and north of Tolaga Bay.

Heavy rain may cause streams and rivers to rise rapidly. Surface flooding and slips are also possible and driving conditions may be hazardous.

For the 16-hour period from 9pm on Sunday until 1pm on Monday.

The forecast is to expect 120mm to 170 mm of rain, with peak intensities of 20mm/h to 30 mm/h Monday morning.

Heavy Rain Watch

In Gisborne/Tairāwhiti south of Tolaga Bay for the 13-hour period from 3am to 4pm on Monday, January 22.

This is forecast to be a period of heavy rain, and amounts may approach warning criteria.

Similarly in the Westland and Grey Districts over the 13 hours from 11pm on Sunday, until noon Monday.

Here, it forecast for periods of heavy rain and amounts may approach warning criteria. Thunderstorms and localised downpours of 25mm/h to 35 mm/h possible.

MetService points out further heavy rain is likely Monday night and early Tuesday morning.