THREE times the normal April rainfall is expected to drench New Zealand in two days as the remnants of Cyclone Debbie that smashed Queensland makes its way across the Tasman, bringing a possibility of a tornado.
The country's weather bureau, MetService, has this morning issued a severe weather forecast for much of northern and central New Zealand.
"Heavy rain and severe gales are forecast for much of northern and central New Zealand today and Wednesday as moist sub-tropical air ahead of a deepening low spreads down over the country," the forecast says.
"Note, there remains a risk of downpours and thunderstorms over northern New Zealand (Wednesday), along with the small possibility of a tornado."
The big weather week was just getting started as ex-Cyclone Debbie slowly moves its way across the country.
"This will be a significant and a high impact even," forecaster Cameron Coutts said, "with extremely large rainfall amounts for some, which could cause flooding.
"For the already soggy regions in the north of the North Island, land-slips are a real possibility following on from an extremely wet March."
Rain is likely for much of the North Island on Tuesday, with the heaviest falls expected in Taranaki and Whanganui, but heavy falls and localised downpours are possible anywhere over the Island.
Strong or gale force winds are also set to accompany the low, most noticeable around the southwest of the North Island and north and west of the South Island Wednesday.
"As there is always uncertainty about the exact depth and track of this low the details may change, so keep up to date on the weather and the latest forecasts," Mr Coutts said.
The New Zealand Herald is reporting that Central New Zealand is on high alert as "the country braces for a deluge so intense some areas will get three times April's normal rainfall in just 48 hours".
Virtually no region in the North Island will escape the potentially damaging torrential rain. It will also affect districts in the northeast of the South Island.
Forecast rainfall for North Island over the coming days
- Northland: Rain is predicted to fall through to Wednesday evening with 180mm in the next 30 hours.
- Auckland: Rain will become heavy this afternoon and fall until Wednesday evening. Up to 150mm is expected in 27 hours.
- Coromandel Peninsula: Rain is expected to get heavy this afternoon and fall until Wednesday night. Up to 300mm is expected to fall on the ranges and 150mm elsewhere across the peninsula.
- Waikato and Waitomo: Heavy rain will fall until Wednesday with 180mm of rain.
- Bay of Plenty: Heavy rain will keep falling until Thursday. Over the next 45 hours, 350mm of rain may fall.
- Taranaki: Heavy rain is forecast to continue until Wednesday evening. In the next 36 hours up to 350mm of rain may fall on the mountain and up to 150mm elsewhere.
- Whanganui: Heavy rain will continue until Wednesday lunchtime. In the next 27 hours a further 200mm is expected to fall on top of current levels.
- Gisborne and Hawke's Bay: Heavy rain is set to continue until Wednesday morning. Over the next 18 hours, 150mm is expected to fall, the worst in the ranges and coastal hills south of Cape Kidnappers.
- Wairarapa away from the Tararua Ranges: Heavy rain is to fall until midday Wednesday with up to 120mm falling across the region.
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