Ongoing wet weather plaguing parts of the South Island is set to spread across the country in time for the weekend.
MetService has issued a heavy rain warning for the upper and central areas of the North Island as well as Nelson, Canterbury and Otago.
A deepening low in the Tasman Sea is expected to propel heavy rain and strong northeast winds across the upper North Island on Saturday afternoon.
The low will make its way down the east coast of the North Island on Sunday.
Rain is due in Northland, Auckland, Waikato, Coromandel Peninsula, Bay of Plenty and northern Gisborne from midday Saturday to midday Sunday, before moving on to Canterbury and Marlborough from Sunday afternoon
Rain should ease by Monday evening or Tuesday morning.
MetService is warning the deluge may cause "significant problems" in Bay of Plenty, eastern Otago and Canterbury, where rain has already caused flooding and slips this week.
Environment Canterbury's Timaru based flood controller Phil Lees said their control room is prepared for flooding with a significant amount of rain predicted to fall in the region in the 48 hour period from Sunday morning through to Monday evening.
The ground throughout the region is saturated from the 320mm of rain that has fallen in the last 10 days.
"There will be significant extra run-off which means local streams and rivers will rise rapidly," Lees said.
"Everyone needs to be prepared as extensive surface flooding will occur very quickly if the rain arrives as predicted," said Lees.
Environment Canterbury is warning farmers to move stock to higher ground as a precaution and is also alerting residents living near flood prone areas to be extremely vigilant.
Check out the latest
forecast here .