Expect wet, windy and wild day, North warned

Northland is being warned to expect increasing surface flooding and possible road closures as the day progresses, with latest forecasts predicting a further 80 to 120mm of rain, topped off by gale force winds this evening.

MetService forecasters issued a new severe weather warning for Northland at 9.15am today, predicting the region may receive 80 to 120mm more rain in the 12 hours to 8pm in areas north of Kaikohe. In parts south of Kaikohe, that rain could fall over a slightly longer period through to midnight.

Additionally, the MetService warns the low moving south over the upper North Island tonight is expected to bring a period of severe east to northeast gales with gusts up to 120km an hour to parts of Northland, with westerly gales behind the low also affecting parts of the region.

Graeme MacDonald, spokesman for the Northland Civil Defence Emergency Management (CDEM) Group, says while the region as a whole appears to be coping well this morning, the next 12 to 24 hours will be pivotal.

With many places – especially in the Far North and Whangarei Districts – already experiencing more than a month's rain since Sunday, the intensity of the further rain forecast today would be crucial.

Mr MacDonald says at this stage, flooding was typically limited to low-lying, flood-prone spots, but that could worsen if the rain fell in bursts of 25-30mm an hour in places as forecast. "This obviously won't happen everywhere, but if it does, the rivers and streams there (which are already well above normal levels) might struggle to cope with that sort of intensity."

In that vein, officials will be keeping a close eye this afternoon on usual surface flooding hotspots including Kaeo, Moerewa's Turntable Hill area, Kawakawa's Three Bridges, the Waimate North Rd, the wider Hikurangi Swamp, Ngunguru, Mangakahia, Tangiteroria and State Highway One at both Whakapara and Mata.

"Winds of the strength predicted later this evening also have the potential to complicate things further, as they will potentially be strong enough to bring down trees and damage powerlines," Mr MacDonald says.

He says officials will be constantly assessing the situation throughout the day, especially around the next high tide, due on the east coast around 5pm.

Northland Regional Council figures show up to 140mm had fallen at Puhipuhi, north of Whangarei, in the 43.5 hours from noon on Sunday until 7.30am today – roughly equivalent to the usual monthly rainfall for the entire month of June.

Council hydrologist Dale Hansen says over the same period, 131.6mm had fallen at Kaikohe, 126.5mm at Wiroa Rd on the high hills east of Lake Omapere, 112.5mm at the Hikurangi Swamp, 111.5mm at Opouteke and 101.5mm at Oromahoe.

Another 77.6mm had been recorded at the regional council's Water St Whangarei offices, a similar amount at the Opua Wharf (77.5mm), 72mm at Kaeo, 71.5mm at Kaipara's Tutamoe Ranges, 64.5mm at Maungaturoto, 46.5mm at Kerikeri and 26mm at Dargaville.

Mr MacDonald says given the combination of factors – including the slow-moving nature of the bad weather – officials are urging a common sense approach today.

"Power cuts are possible, as are road closures, surface flooding and slips. Consider the risks, take the necessary precautions and don't travel unless you really need to. Given the predicted winds, boaties – if they haven't already done so – should also make sure their vessels are secure."

He says Civil Defence will update the public as required, including through the Northland CDEM Group's Facebook page – www.facebook.com/civildefencenorthland

Information about any local district council road and State Highway closures/issues in Northland while the warning is in force is available from the Automobile Association website via www.AAroadwatch.co.nz

The site contains a map and brief description of closed/affected roads and an indication of when the issue/s involved is likely to be resolved.

General Civil Defence information is also available from the Northland Regional Council's website www.nrc.govt.nz/civildefence