Winter is coming – get the layers ready and hang on to your hats.
We're into the start of winter and this one could be an interesting one for a variety of reasons.
Most times at the start of winter you get the merino layers ready and get things geared up for the wild ride of what's to come.
That will certainly be the case with a few more things in the mix too.
You may have heard already a lot of talk from around the globe about a new phase of El Nino setting up across the planet in the next two to four months.
Some of the talk around this one is that is has the potential to be a super El Nino. Yeah, Super El Nino.
Could a 'super' El Niño be on the way? What it means for NZ - Watch on TVNZ+
Let's rewind a bit
Let’s rewind a bit first. What is an El Nino phase and what did we just have this past summer?
This past summer in New Zealand featured a weak La Nina phase of the ENSO (El Nino Southern Oscillation) pattern.
The prevalent humid northeast winds and numerous visiting tropical lows soaked much of the country in copious amounts of rain.
The current phase of ENSO is neutral but there are increasing chances that the phase will shift to El Nino by the end of our winter.
In El Nino phases the opposite occurs to La Nina. Instead of warm humid northeasterlies and rainmaker tropical lows the weather pattern shifts the fronts and rainmakers to the south of the country.
Drier westerlies blow further north as the anticyclones track further north. This global pattern can also affect weather forecasts for much of the planet. Early indications are that it has the potential to become a very strong El Nino during our 2026-27 summer.
That said, climate forecasts tend to be made by global meteorological centres at the least accurate time of year - the northern hemisphere spring when residual seasonal wind bursts can affect the climate model accuracy.
That is not to say the potential is not there, but there are also many factors that affect the makeup of our weather these days, not just one.
Many people also don’t recall but about a decade ago a big El Nino was forecast and it did not eventuate.
So, what are we in for?
Buckle in though, the next few months could be quite a ride for the weather.
One thing for sure is don’t expect the early days of winter to bring some big dark ugly El Nino cloud rolling past your front door.
El Nino doesn’t affect individual clouds or weather systems quite like that.
One thing that will happen is that the first half and second half of winter could be quite different as El Nino takes shape and starts to bite across the Pacific.
The first half of winter could bring a more typical winter as the ENSO neutral phase is still in the driving seat.
This will bring us a good mix of weather from passing active rainmakers, passing highs and cold surges from the Southern Ocean.
The active rain makers could linger for a time, increasing rainfall chances to northern and eastern areas.
The cold surges will see us making good use of the merino layers as well as dusting off the skis when the conditions are just right.
In the second half of winter, we will see the influence of the building warmth in the atmosphere to the northwest of New Zealand.
This will bring plenty of fine dry days to a good chunk of Australia, with the knock on effect of the wind flow bringing more west to west southwest winds across the country.
This will in time reduce the rain chances to northern and eastern parts of the country.
In this type of pattern, if the El Nino becomes very strong during our spring, it could lead to significant drying conditions to some eastern parts of the country.
That could carry on into the summer too. This will be something to watch.
The other wild card that doesn’t get mentioned but plays a big part in our weather these days is the extreme weather element - in particular - the very warm seas that continue to exist around New Zealand as well as the much juicier atmosphere.
These factors given the right environmental conditions can lead to extreme weather events almost anywhere at short notice.
So, enjoy the winter. Get the woodpile ready but watch out for the odd weather surprise.
Could a 'super' El Niño be on the way? What it means for NZ - Watch on TVNZ+
SHARE ME