It’s still a long way out but the computer modelling we trust most is suggesting high pressure will be exiting New Zealand around Christmas time – and when a high pressure zone leaves NZ it often drags in warmer airflows from the north to north west.

WeatherWatch.co.nz says with still more than 10 days to go this is by no means locked in yet, but the timing of this next high is looking pretty good if you’re wanting some bigger dry spells just before Christmas – and hopefully during it.

The high pressure zone will first bring a wintry southerly change to Australia and even southern NZ. For example, Melbourne has a high of only 14C today with that southerly (but one week from now on the back of that high pressure zone it jumps to 28C). Dunedin has a high of around 20C today, but drops to 12C on Sunday and 11C on Tuesday next week as the high pressure zone first starts to move in with southerlies says WeatherWatch.co.nz.

High pressure should track over the South Island late next week – but could leave northern NZ exposed to lower air pressure and a chance of some showers and afternoon downpours. West to Nor’west winds may also pick up in the lower South Island, bringing cloud to the west and south but sunnier, hotter, weather in the east.

Of course, this is all based on computer modelling and this far out the timing is the biggest issue. “We can see air pressure zones one to two weeks out, but the precise timing of their movement through NZ will be the main deciding factor for Christmas Day’s weather forecast” says WeatherWatch.co.nz head forecaster Philip Duncan. “That will take until next week to lock in”.

Modelling has been consistent with the above forecast for five days now – but it could still change.

WeatherWatch.co.nz is now providing Christmas Day weather updates in our week day weather videos across this week and next week too. You can view them here: www.youtube.com/c/WeatherWatchNZ1

• Christmas emojis courtesy Flaticon
• MAP: 12 Noon Christmas Day air pressure map showing downpours too.