Flooding caused by heavy rain in Northland overnight has left roads like rivers, trapping some people in a dairy and closing a number of schools.
Parts of the north had 70mm of rain in less than 12 hours, and more is forecast.
Beryl Panther, who runs the Bush Fairy Dairy in Peria, 25km east of Kaitaia, said three or four customers were stranded at the shop as the water came up so quickly.
She said the Honeymoon Valley River was still rising and had flooded the carpark, road and paddocks, with water standing three quarters of the way up signposts.
"When I look out my front door, even my carpark is underwater, it's like a big lake.
"I've got people stuck at the shop because just in the time they came to shop, the flood came up so much that cars can't use the road at the moment.
"You can't even see the road. Luckily the shop is built up a bit but underneath the shop, water's running under it.
"If I try to get home I'll have to get my husband to come on the tractor and pick me up."
Schools in the Taipa and Kaeo areas have been closed, with buses unable to run.
State highways are open at this stage, but many rural roads are underwater.
The Northland Regional Council said the region had no weather warning, but the heavy falls were very localised.
Severe weather warning issued
MetService has issued a severe weather warning for many parts of the North Island today.
The heaviest rain is due to fall throughout the Bay of Plenty and northern Gisborne, with up to 100mm of rain due over the 18 hours from 9am today.
MetService is warning people in these areas to watch for rapidly rising rivers and streams. Slips and surface flooding is also possible.
Thunderstorms are predicted to move south through Northland, Great Barrier Island, and northern parts of Auckland and the Coromandel Peninsula this morning.
The wild weather is being caused by a low from the Tasman Sea, which is expected to cross the upper North Island tomorrow, MetService said.
The front is also expected to bring severe gales to the Auckland region early afternoon.