High pressure is covering NZ right now and another big high is expected in just over a week, likely bringing a settled end to September and start to October. However in between we do have a burst of wind and rain from a low.
The belt of high pressure, which has been stuck over Australia and not really moving NZ’s way in recent months, has started to move around a bit more lately. We have a powerful high pressure system moving in over the New Zealand area between now and Monday.
Next week, from Tuesday to Thursday, we get a typical cooler and windier south west change. However by the end of next week it’s likely that another high pressure system will break from Australia and come our way. This next high may be centred further north though, this would allow a westerly flow to continue over the South Island and up to around Cook Strait – so not quite as calm and settled as the high coming in now although those winds may help lift temperatures up in the east.
Either way it means the month of September will likely end on a mild note, also on a dry note for northerners and those in the east – once we get past the mid week cool down next week.
The late September high looks likely to linger into early October but may well be pushed away quickly by a windy westerly.
It’s important to note that October is one of New Zealand’s most chaotic months on the weather calendar. Usually by November things start to settle down again as we tip towards the ‘summer side of spring’
Above – GFS map for September 30th
Below – ECMWF map for September 29th