The forecasted weather bomb has seen a change in wind direction at the scene of a massive bush fire south of Whitianga.

Thames Valley deputy principal rural fire officer Peter Smith says although that will bring rain, it also brings new and volatile challenges for fire and Department of Conservation crews tasked to work on the fire at Comers Rd, Kaimarama, south of Whitianga, this morning.

The blaze has already ripped through 70ha of bush, scrub and homes, as well as wiping out most of the Wilderland Sustainable Community settlement.

Smith said thanks to GPS mapping, they were late yesterday able to confirm the size of the fire which now stretches 70ha.

Fire crews gather for a morning briefing before tackling the Coromandel fire. Photo / Belinda Feek
Fire crews gather for a morning briefing before tackling the Coromandel fire. Photo / Belinda Feek

It had also taken out four homes, he said.

Just after 3pm today, the NZ Defence Force said it would be sending firefighters to the area to help battle the blaze.

Five experienced firefighters were being deployed to Whitianga to help.

Major General Tim Gall, Commander Joint Forces NZ, said their firefighters - four from the Army and one from the Air Force - were being sent following a request from the National Rural Fire Authority.

"Our firefighters have vast experience here and overseas in fighting bush fires. Last year, we sent 10 firefighters to remote bushland in northwest Tasmania to help battle the state's bush fires for about a month,'' General Gall said.

"We will do our best to assist the local community in Whitianga and hope that our firefighting crew will be able to help get the blaze under control soon.''

This morning, crews arrived for an 8am briefing where authorities will set a plan for the day.

The wind change will hopefully bring rain with the weather bomb, but in the meantime it means the changeable winds could whip up new hotspots.

"Ideally you want rain with no wind ... there is quite strong erratic winds ahead of the incoming weather bomb, so we're hoping for the best and hope the winds don't give us too many embers and have some ember transferrage onto fuel [trees]."

Just up the hill, resident Amy Rogers, who has been looking after affected residents since the fire took hold yesterday, was busy cooking bacon, egg and salad rolls for hungry and exhausted fire crews.

She said reports of four homes being destroyed in the blaze was wrong and said only two residences had been lost, the rest of the buildings were part of the Wilderland community.

After putting up a few shocked residents the previous night, only one neighbour stayed last night. Others affected by the fire either stayed with friends or family, or spent the night in a motel.

At a briefing this morning, planning officer Rory Renwick told firefighters the northwest winds would rise up to 30km/h by midday, which would cause gusts of up to 50km/h.

"And with rough terrain plus this is not exactly flat, we will get wind from all sorts of directions and get gusts and flare-ups."

Planning officer Rory Renwick and Graham McIntyre at this morning's fire briefing.
Planning officer Rory Renwick and Graham McIntyre at this morning's fire briefing.

He said there were "multiple structures" inside Wilderland, "we're not even sure how many."

He told firefighters they needed to have their wits about them as the wind change had the potential for dangerous "uphill runs" - with the fire running uphill at a rapid pace.

Operations manager Dennis Cooper agreed there were serious concerns with the wind's volatility.

"With the NW change, we're concerned about fire coming back down the peninsula, or back towards us.

"We're expecting another wind change this afternoon."

Cooper said the fire looked like it was out but it wasn't that clear-cut yet.

"Looks like it's out but there are flare-ups and wind change and unburnt fuel, so be careful about where to go and what do."

Deputy Principal Rural Fire Officer Mike van Bysterveldt said there would be two bulldozers and diggers cutting firebreaks to contain the area.

Twenty-six people were evacuated at the fire's height.

Among them was Jani Dennis and neighbour Helen Lee, who had mere minutes to evacuate, grabbing her cellphone and precious saxophone.

All of the instruments used by the Mercury Bay Big Band were lost in the blaze.

"They'll all gone, everything," Lee said.

Despite valiant efforts by her neighbours Michael and Aaron Blowfield, who frantically cut down trees to slow the fire, the blaze surrounded her house and destroyed it.

Lee and other evacuated residents were today still in shock and many gathered at another resident's home at the cordon on Comers Rd, crying and hugging as their loss sinks in.

"The fire was too big, there were too many fronts," Lee said.

"It was everywhere. It was here, it was there, it was over there."

Dennis says despite the losses, she's glad that everyone escaped with their lives.

"We're just lucky that everyone got out because there's only one road out and no one knew exactly where the fire was."

She said it was a horrible experience.