High pressure still dominates a big chunk of the weather across New Zealand and Australia as we go into June, but low pressure zones are increasingly in the mix.
The neutral weather pattern allows for more chaos and over the past couple of weeks NZ has had a more chaotic pattern with wind flows from all directions and a combination of rain, snow and heavy downpours affecting many.
From a soil moisture point of view the driest parts of the country lie in central NZ – from southern coastal Taranaki and Whanganui through to Nelson and Marlborough and Canterbury.
Most of these regions have variety within them. Some have had rain and others not enough. The soil moisture anomaly maps we have at RuralWeather.co.nz paint a picture of wetter weather around the country, but still some pockets of dry.
As NZ gets some rain relief our Aussie neighbours do too – with the first significant rain event and cold front so far this year for some in the southern half of the continent.
May can be defined as the month of mountainous high pressure parked around Tasmania; this month we still see more highs in that part of the world but they are moving along faster and in between them there is a windy, westerly, flow (far more normal) kicking back in.
These westerlies can sometimes reach NZ, bringing western rain. Considering a large chunk of our weather comes from the west, it’s worth noting what is happening in places like Perth, Adelaide, Melbourne and Hobart to see if there are changes to the pattern so far this year – and there are. Southern Western Australia and the southeastern corner of Aussie both look to get a couple of rain events in very early June. This bodes well for NZ getting some of the leftovers in the weeks ahead.
But high pressure is still in the mix – there may be at least three or four large highs around southern Australia, the Tasman Sea and NZ area over the next couple of weeks. These highs will bring a variety of wind flows, often moving in with cooler southerlies and then departing with milder nor’westers. The shape of these highs matters most. Shaped like a rugby ball standing up about to be kicked makes them often colder and frostier (more southerlies) than the highs shaped like a rugby ball lying on its side (which brings more sideways weather – or westerlies and easterlies).
Rainfall-wise, for the first half of June we are expecting rain to be near normal or a little lower than normal except for the West Coast and maybe Northland. We’re seeing a classic westerly flow, which keeps places like Canterbury the driest.
Upcoming Highlights:
• Monday kicks off with high pressure encouraging a cooler but fairly dry sou’west flow across the country
• High pressure covers NZ on Tuesday (frosts possible)
• A large but weak low in the Tasman Sea may produce some cloud and showers in the west by mid to late week
