The MetService has released a severe thunderstorm watch this morning from Hawke's Bay to Auckland, including Rotorua.

A trough in a moist northerly flow is expected to bring heavy rain today to central and northern parts of the North Island including Rotorua, Taupo and Bay of Plenty.

The MetService says the trough could be accompanied by torrential rain of 25mm to 50mm or more per hour, which can cause flash flooding and slips.

It says low-lying areas such as streams, rivers or narrow valleys are most at risk of flooding, and driving conditions will be hazardous with poor visibility.