Another torrential downpour on cards for the Bay

Torrential rain last night saw Napier drivers slowing to snails pace and flash flooding in some of the city's streets.

Although Hawke's Bay Airport recorded only 11mm of rain, Weather Watch's Philip Duncan said the Napier hill more than likely experienced more rain than that.

"There's only a few weather station that the government has got and the heavy rain clearly missed them last night," he said.

Yet despite the brief but intense rain-storm, which occured about 5.45pm, such localised downpours and flooding are nothing unusual.

"We've been seeing these weather patterns around both islands for the last month or so and it's not abnormal. December is still technically spring, so you can quite typically get a mixture of warm and cool weather which is what happened yesterday, and that produces these big downpours or what we like to call 'localised'."

Duncan said he had seen cases where one end of a street was completely saturated and the other end was as dry as a desert.

"It's because these weather systems don't move very quickly, so anything can happen underneath them, you can get a flash flood, hail, thunderstorms-but you could be a few blocks over and be completely dry, so you could just sit on your porch and watch the action from your balcony."

Shops in Napier had to close early due to the heavy downpours with Pacific Souvenirs placing the sign "closed for flooding" on their window. Postie and Amazon were also forced to close their doors early, despite many businesses trying to stay open for late night Christmas shopping.

Metservice meteorologist James Millward agreed that weather of this nature was not unusual.

"The story is actually the same today, we've got very similar weather patterns passing through Hawke's Bay. So we're at risk of thunderstorms around the ranges, so you might see some heavy showers in the region again this afternoon and evening.

"There was some heavy rain in the region last night, Wairoa saw 15mm in an hour last night and the day before it recorded 27mm of rain."

Millward said the sporadic weather patterns were nothing unusual given that New Zealand was sitting in the middle of El Nino and La Nina, making the cycles difficult to predict over the coming months.