Australian bush fires: Smoke and ash continues to drift across NZ, reaching Auckland at midday

Smoke from the Australian bush fires is heading across the Tasman to NZ. Photo / Getty

Smoke from the raging Australian bush fires continues to drift across the Tasman Sea, with forecasters expecting it to descend on Auckland around lunchtime today.

As scorched, devastated communities of NSW and Victoria brace for more high temperatures and fanning hot northwest winds tomorrow (Saturday), ash and smoke is still travelling more than 2000km west.

Most of the thick smoke seen across the South Island earlier this week, which turned Fox and Franz Josef glaciers caramel brown and blocked out the sun in many places, has mostly now passed over New Zealand.

But MetService meteorologist Rob Kerr says a "weaker feature" is currently passing over Waikato and is heading towards Auckland.

Thicker smoke caught up in the front will be sweeping northwards over Auckland & Northland this morning. Finer particles higher in the atmosphere, in a more westerly flow than the SW at the surface, are still being blown towards the rest of NZ. ^RK pic.twitter.com/vtRsWC74BA

— MetService (@MetService) January 2, 2020

It's expected to pass over the country's main metropolis around midday, before heading over Northland and out to sea.

Some showers are expected but once the cloud clears, Aucklanders can expect to experience some hazy skies, Kerr says.

"It won't be as bad as what we've seen over the South Island in recent days but it will be noticeable," he said.

The mercury is expected to top out at 22C in Auckland today.

A cold front moving up the East Coast today should sweep most of the smoke and ash away today.

However, with thousands of people being evacuated from towns and national parks in the path of the raging "firestorm", Kiwis can expect to see graphic reminders of the disaster unfolding over the Tasman in the coming days.

More northwest winds are expected to push another front over New Zealand on Sunday.

Weak front moving over Waikato and towards Auckland this morning. Cloudy, but not much rain with it, then followed by clearer skies and cooler southwesterlies.https://t.co/7k3nmdWQwx ^RK pic.twitter.com/EO3LmdjpuB

— MetService (@MetService) January 2, 2020

It's expected to reach the North Island in the early hours of Monday morning, Kerr said.

The bush fire's smoke, which has been smelled by Cantabrians this week, has generally been taking 1-2 days to reach New Zealand.

The "thick river" of smoke flowing across the Tasman spiked PM10 levels – a measure of particles in the air continuously measured at regional council monitoring stations in most larger and some small towns by 3 - 5 times normal levels yesterday and on New Year's Day, NIWA says.

The sequence, which started in Southland before gradually moving up the South Island, saw the smoke travelling like a "swirling, braided river with thicker and thinner channels", according to NIWA air quality scientists Dr Ian Longley.

Where it was monitored, the smoke was neither thick enough nor persistent enough to breach National Environmental Standards for Air Quality – which are expressed as an average over 24 hours.

Longley said the average concentration of smoke that impacted the South Island were at most a third of the levels that have regularly been recorded in urban Sydney over the last month.

By yesterday morning, the thickest part of this smoke river had passed New Zealand and was heading out into the Pacific.

However, a thinner remnant is leading to elevated PM10 still being recorded in the top of South Island.

Bush fires have been raging out of control across NSW and other states in southern eastern Australia for three months.

Eight people have now been confirmed dead, with hundreds of homes and other buildings including schools and businesses, destroyed. It's also been claimed that half a billion animals have perished in the fires since September.