What will the weather do next?

4:34 pm on 8 March 2017

Boy, has it been rainy, floody and slip-y.

Heavy rain in the Clevedon area, south of Auckland, has swamped streams and rivers.

Heavy rain in the Clevedon area, south of Auckland, has swamped streams and rivers. Photo: RNZ / Sarah Robson

Mother Nature has offered the Upper North Island a brief reprieve from torrential rain and lifted its thunderstorm warning (except for you, Northland) - but do not reach for your sunblock just yet.

Heavy rain is expected to return to the Coromandel, Auckland and the Bay of Plenty on Friday.

MetService meteorologist Tom Adams said until then, the upper North Island would "still get bits of rain" - "not nearly as much as the last 24 hours", but enough to "keep it miserable".

Unaffected areas were unlikely to flood, but the flooded areas would likely stay that way.

"When the heavy rain comes back on Friday, everywhere will be saturated."

That had the potential to cause more flooding, slips and debris on roads.

The "blocking high" causing the rainy weather would "escape" on Sunday or Monday, he said.

How much rain was there?

MetService duty forecaster Heath Gullery said the heaviest rain overnight Tuesday-Wednesday was 160mm in the Hunua Ranges.

Flooding at the Kauaeranga River mouth in Thames on 8 March 2017.

Flooding at the Kauaeranga River mouth in Thames. Photo: Waikato Rescue Helicopter

Areas south of the Manukau Harbour and on Waiheke Island had between 80mm and 150mm.

"It looks like the peak rainfall rates per hour in some of those places were around 30 to 40 millimetres per hour," Mr Gullery said.

The torrential rain in east Coromandel was about a one-in-100-year event, the National Institute of Water and Atmospheric Research (NIWA) said.

Some areas received more rain in two days than normally fell in the entire month.

In eastern Coromandel, Whangamata had 259.8 millimetres of rain fall in less than 36 hours, NIWA said.

That was more than 150 percent of the normal rainfall for March.

Waihi Beach recorded more than 220mm of rain within 24 hours. That happened about once in 60 years.

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