Metservice says a front lies slow moving through the southern parts of the Westland District, bringing heavy about the ranges of the Westland District. 

"Meanwhile, a subtropical low develops to the northeast of the country during Monday and will bring heavy rain to northern and eastern parts of the North Island," says a MetService spokesperson.

The heaviest rain is expected through Gisborne and Hawke's Bay during Tuesday and Wednesday. 

Tuesday, May 21
A low pressure system is expected to be located near the northeast of the North Island, bringing rain in an easterly flow to northern and eastern parts of the Island. 

For areas from Northland to the Coromandel Peninsula, there is low confidence that rainfall accumulations will reach warning amounts. However, for Gisborne/Tairawhiti and Hawke's Bay the risk increases to moderate.

Additionally, east to southeast winds are likely to strengthen across the central North Island, and there is low confidence they could reach severe gale about and west of the ranges from the Raukumara Range to the Ruahine Range. 

Wednesday, May 22
The low pressure system located near the northeast of the North Island, is likely to continue to bring significant rain to eastern parts of the Island, and there is moderate confidence for warning amounts of rain in Gisborne/Tairawhiti and Hawke's Bay.

Additionally, east to southeast winds could still be strong across the central North Island, and there remains low confidence they could reach severe gale about and and west of the ranges from the Raukumara Range to the Ruahine Range.

Thursday, May 23
The low pressure system remains slow moving to the north of the North Island, bringing further rain to eastern and northern areas of the Island.

There is low confidence for warning amounts of rain in Hawke's Bay, Gisborne/Tairawhiti and the Coromandel Peninsula.

Friday, May 24
A cold front followed by southerlies moves north over the South Island, while the flow over the North Island turns to the south southeast.

There is low confidence for warning amounts of rain about northern Hawke's Bay and Gisborne/Tairawhiti.