Long range weather forecasts suggest a tropical cyclone will develop near Fiji shortly, with some models predicting it could bring inclement weather to Aotearoa near the Christmas period - but NIWA says it's really still too far off to tell.
Forecast models from both the European Centre for Medium-range Weather Forecasts and the Global Forecast System suggest that the system will develop over the weekend and early next week.
By December 20, both services have the system in the southwest Pacific north or north-west of New Zealand.
However, the predictions are being tempered with caution, as long range forecasts are generally inaccurate, and a better picture of the storm's track will become more clear from next week onwards.
Media reports this week have played up the risk of the storm hitting New Zealand before Christmas, but NIWA's Principal Scientist of Forecasting and Media Chris Brandolino said "there is a LOT of uncertainty".
'It's certainly worth watching, as we are doing at NIWA, but I wouldn't be modifying any Christmas plans yet," Brandolino said.
"But certainly, it is worth keeping an eye on the forecast, which people should be doing anyway, irrespective of this.
"The 'thing' is just starting to develop - Fiji Met has it as a tropical depression now (one stage below a proper tropical cyclone).
"Until it has really developed, weather models have a higher chance of struggling to 'see' it at the start of the forecast, and therefore, how it behaves going forward needs to be taken with a grain of salt, especially in early days."
Brandolino provided an animation of an "ensemble" forecast, which essentially shows all of the current potential paths of the weather system at this point in time on the same map, right up until Christmas Day.
The ensemble forecast does show some paths where the low pressure system comes to New Zealand, but also shows several paths where where it does not.
According to the ensemble forecast, there's reasonable confidence that a large patch of high pressure will move onto the country over the weekend and into next week.
Brandolino said that, temperature-wise, it was likely to be warmer than usual from next week up until Christmas, and possibly humid.
NIWA and MetService said in a joint release in October that New Zealand faces an "elevated" risk of tropical cyclone activity this season (November to April) due to higher temperatures.
As opposed to one ex-tropical cyclone expected to affect New Zealand, we can expect 1-2.
That prediction was based on identifying "analogue" years to 2020 which had similar conditions - one of which was the 2017-18 season, which produced Cyclones Gita and Fehi.
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