The country is drying out faster and earlier than usual as El Niño begins to bite, prompting Fire and Emergency NZ to start preparations for a potentially busy fire season.
FENZ acting service delivery wildfire manager Rachael Thorp said current conditions are similar to 2018 and, given that El Niño can rapidly change, officials have started monitoring conditions, regularly checking weather stations and receiving climate updates.
She said FENZ is planning for the east coasts of both islands to be dry from Northland to South Otago and exposed to west and northwest wind.
A wet and warm late winter and early spring have encouraged grass growth that, when it cures, will provide an abundant fuel load.
The Bureau of Meteorology in Australia this week declared an El Niño weather event for both countries and WeatherWatch chief forecaster Phil Duncan said it is likely to be strong.
“I think by the end of October we will start to see which areas in NZ are drying out quickly,” he said.
He said the South Island’s West Coast and Southland will be wetter than normal but the wet weather will taper out as it moves north up the west coasts.
Some isolated eastern areas are likely to reach 40degC-plus temperatures on occasion, fuelled by northwest winds emanating out of central Australia.
While warning of a strong El Niño weather pattern, Duncan said NZ’s exposure to the Roaring Forties could see several rain events hit the country, potentially easing conditions.
Weather systems look especially harsh for Australia, with El Niño on the east coast and a positive Indian Ocean Dipole system on the west. Both encourage dry weather systems.
The Bureau of Meteorology long-range forecast is for warmer and drier than average conditions across most of southern and eastern Australia from October to December.
Duncan said Sydney hit 35.5degC this week, the highest September temperature since 1930.
In NZ, the early arrival of dry conditions means a restricted fire season already applies to Nelson, West Coast and central Otago, the far north of Northland, the central North Island and parts of the Bay of Plenty, Hawke’s Bay and Wellington.
Thorp is urging landowners to carefully check controlled fires are extinguished, even several weeks after dying down.
This is especially significant given recent windy weather reigniting smouldering embers.
In the past month there have been 13 flare-ups in Hawke’s Bay, two in Wairarapa and one in Canterbury, which spread to a hedge and then to a house roof.