MetService has issued a severe thunderstorm watch for the Bay of Plenty, Taupo, Gisborne and Hawkes Bay on Christmas Day.

Scattered thunderstorms are again expected to affect parts of central and southern New Zealand this afternoon and evening, with localised heavy rain and small hail, says a MetService spokesperson.

"About the ranges of eastern Bay of Plenty, inland Gisborne, inland Hawke's Bay (mainly the western ranges and south of Hastings) and eastern Taupo, some of the thunderstorms could be severe between about 3pm and 9pm today, with localised downpours of 25-40mm per hour.

"There is also a low risk of a small and very localised tornado within this area."

Rainfall of this intensity can cause surface and/or 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.
Note, this is likely to affect the Napier-Taupo Road, and possibly parts of SH2 in Central Hawke's Bay south of Hastings.

MetService says the thunderstorm activity should die away late evening on Christmas Day.

A Severe Thunderstorm Watch means conditions are favourable for severe thunderstorms in and close to the watch area. People in these areas should be on the lookout for threatening weather conditions and monitor for possible Severe Thunderstorm Warnings.