A severe weather warning applies to Northland as a thunderstorm with the potential to make a mess moves over the region tomorrow.
MetService stepped up its warning today after the intense low coming in from the Tasman Sea deepened.
Rainfall of the expected intensity can cause flash flooding, especially about low-lying areas such as streams, rivers or narrow valleys, and may also lead to slips. Driving conditions will also be hazardous with surface flooding and poor visibility in heavy rain, MetService warns.
Localised downpours could drop 25 to 40mm an hour as the rainband moves across Northland and Coromandel Peninsula during the morning.
The warning will be updated by 9.30 pm tonight.