Rain will ease but muggy weather to stay a bit longer

There's good news and not-so-good news for weather watchers, as the Northland remains drenched from nearly a week of rain: The bad weather should subside over the weekend, but the sticky, wet nights will linger until the end of next week. .

MetService meteorologist April Clark said Northland had been hit by strong winds and heavy rain for almost a week – which followed the start of a wettest year in the region – with an orange heavy rain warning for Northland until 6am today.

“It's not just a day for Northland though, it's been on and off there for such a long period of time. You've been hit by the weather recently.

Clark said the upper half of Northland suffered the worst of yesterday's weather, with surface flooding closing some roads.

In the 24 hours up to 3:00 pm Friday, Cape Reinga recorded the highest rainfall total with 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 due to flooding, all in Doubtless Bay and wider areas of Kaitāia.

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

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

Roads that were open but required caution included West Coast Rd, Waiotehue Rd, Church Rd, Waiotemarama Gorge Rd, and Hooks and Halls Rd. Wekaweka Rd, in southern Hokianga, was passable, but drivers had to avoid large strewn rocks by 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 at around 12:30 pm, kneeling in the floodwaters and clearing a blocked drain by hand. The flood water quickly dissipated.

"It's clear from those [rainfall] estimates that the system has been moving slowly across the country, and starting Saturday it will start moving south,” Clark said. “But it has meandered back and forth over Northland a few times and it has really stuck.

“It brought in some warm, humid air on what we call a warm transporter, which is like a conveyor belt that brings in the really humid air from the subtropics. As a result, the temperatures overnight have been very high for the time of year and cause all that humidity that makes it difficult to sleep at night.”

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

“For example, Whangārei forecast an overnight low for Friday of 21°C, but the overnight low is forecast to be 18°C. That's not a big difference at all and why do you feel the sticky heat at night.

"Normally you'd be happy with those temperatures during the day, but at night, with the clouds acting as a blanket to keep you warm, it can make it a bit unbearable."

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

Clark said most of the rain will be gone by Monday or Tuesday, with the possibility that the system could get back up and running in the region, but the end of the sticky nights will take a few more days.

On Thursday, cooler air would blow in to "moisture away" and ease the muggy weather. Overnight temperatures should start to drop thereafter.

Clark said that with the amount of rain Northland had received in recent months, the ground was very soggy, so more rain increased the potential for flooding and slippage.

Meanwhile, Niwa's weather forecast for the three months to the end of July predicts that Northland will see warmer-than-average temperatures, while rainfall is expected to be normal.