Northland rain likely to go from weekend, but muggy nights to stay a bit longer

Rainbow Falls, in Kerikeri, was a torrent around 2pm on Friday with flood waters created by the storm hitting Northland. Photo / Peter de Graaf

There’s good news and not-so-good news for weather watchers as Northland remains sodden from almost a week of rain: the bad weather should ease over the weekend but sticky, humid nights will remain until the end of next week.

MetService meteorologist April Clark said Northland had been battered by strong winds and heavy rain for almost a week – which followed the wettest start to a year ever in the region – with an Orange Heavy Rain Warning in place for Northland until 6am today.

‘’It’s not just one day for Northland, though, it’s been on and off up there for such a long period of time. You’ve been hammered by the weather recently.’’

Clark said the top half of Northland got the worst of yesterday’s weather, with surface flooding closing some roads.

In the 24 hours to 3pm on Friday, Cape Reinga recorded the highest rainfall total of 84mm. Kaikohe recorded 70.2mm during the same period, with Kaitaia getting 67mm, Whangārei 29.8mm and Dargaville 27.8mm.

On Friday afternoon four roads in the Far North were closed by flooding, all in the Doubtless Bay and wider Kaitāia areas.

They were Taumata Rd, Taipā; Whangape Rd, Herekino; Peria Rd, Peria; and Inland Rd, Karikari Peninsula. Motorists needing to access Karikari Peninsula had to use the Inland Rd bypass. Kaitāia-Awaroa Rd and Commerce St in Kaitāia reopened after closing on Thursday due to surface flooding.

Another 13 roads across the Far North had restricted access due to flooding, overslips, washouts or fallen trees. Miro Place, Mangatoetoe Rd, Duncan Rd, Wireless Rd and Bell Rd, all in the Kaitāia area, were passable by four-wheel-drive vehicle only.

Roads that were open but where caution was required included West Coast Rd, Waiotehue Rd, Church Rd, Waiotemarama Gorge Rd, and Hooks and Halls Rd. Wekaweka Rd, in South Hokianga, was passable but drivers had to avoid large boulders scattered on the road.

Kerikeri Rd, near the intersection with Access Rd, was affected by significant surface flooding after a late morning downpour.

Two police officers were seen going well beyond the call of duty around 12.30pm, kneeling in the floodwaters and clearing out a blocked drain by hand. The floodwater quickly dissipated.

‘’It’s clear from those [rainfall] figures that the system has been coming slowly down the country, and from Saturday will start heading south,” Clark said. “But it’s meandered backwards and forwards over Northland a few times and has really hung around.

‘’It’s brought some warm, humid air with it on what we call a warm conveyor, which is like a conveyor belt bringing the really moist air from the subtropics. As a result, overnight temperatures have been very high for the time of year and causing all that humidity that makes it hard to sleep at night.’’

Clark said overnight temperatures had been 4C to 8C above May averages, with such a small gap between daytime highs and overnight lows.

‘’For example, Whangārei had a forecast overnight low for Friday of 21C, but the overnight low is forecast to be 18C. That’s not a big difference at all and why you are feeling the sticky heat at night.

‘’You’d normally be happy with those temperatures during the day, but overnight, with the clouds acting like a blanket to keep the heat in, can make it a bit unbearable.’’

Whangārei and Kaitaia are forecast to have an overnight low of 17C tonight and Sunday, with highs of 20C in both centres.

Clark said the rain would largely be gone by Monday or Tuesday, with a chance the system could turn back on the region, but an end to the sticky nights would take a few days longer.

On Thursday, cooler air would arrive to “chase the humidity away” and provide some relief from the mugginess. Overnight temperatures should start drooping from then.

Clark said that, with the amount of rain Northland had received in recent months, the ground was very sodden, so more rain increased the chance of flooding and slips.

Meanwhile, the Niwa climate forecast for the three months to the end of July predict Northland will have warmer than average temperatures, while rainfall is expected to be around normal.