An abnormally large belt of high pressure is moving in to New Zealand with drier than average weather for the rest of June and some places likely not receiving any rain between now and early July (not so normal for this time of the year).
It’s the second very large high in the past two months to influence our weather and WeatherWatch.co.nz head forecaster Philip Duncan says it’s part of pattern we’ve seen for months with dry and mild highs coming out of the Australian area. “This year has been generally warmer and drier in New Zealand due to an uptick in large highs which have been drifting out of Australia. NZ is such a small country and we’re partially in the Roaring Forties belt of changeable weather so it means that a series of big highs or lows can seriously throw our averages out”.
Australian drought conditions have been going on for years in some States but this year things have become more widespread with now even talk Sydney may have water shortages in the coming decade.
Mr Duncan says New Zealand is being somewhat affected by their drought conditions. “The nation of Australia has been hit hard again this year by these overly powerful, stubborn, highs – one after the other, after the other. With NZ so close to their east and our weather pattern often coming from them, it’s perhaps not so surprising that we’ve caught some of their dry weather bug”.
Across NZ dry regions have had recent rainfall which has been good for getting soil moisture levels closer to normal – but it won’t take long for this to reverse. Incredibly, rainfall totals in many regions are well below normal for the halfway point of the year with some only getting about one third of where they should be. “Lack of rain in winter is great news for most townies but for farmers and growers it makes things more worrying heading into spring and summer when rainfall traditionally dries up a bit. To start off dry is not ideal for summer 2019/2020 for dairy and vegetable prices”.
Of course the peak of winter is yet to arrive and rain may still be coming in – again due to our small size we can’t lock in things too far out.
The incoming high will dominate our weather bringing no rain to some parts of the South Island over the final week of June.
Most of the rain you see in the 7 day rainfall accumulation maps below will be falling today, Sunday June 23rd.
For those worried about the lack of rainfall in New Zealand we do have some better news than our Australian friends. At the end of this enormous high there may be a period of unusually warm sub-tropical airflows. While not the best news for making snow on ski fields it is a better set up for bringing rain in to dry farms and market gardens with lows more likely in the Tasman Sea.
NOON TODAY (JUNE 23)
NOON WEDNESDAY (JUNE 26)
NOON FRIDAY (JUNE 28)
NOON NEXT SUNDAY (JUNE 30)
UPCOMING 7 DAY EXPECTED RAINFALL COMPARED TO NORMAL – Extremely dry over the South Island in particular. The entire country (in red) is drier than average. (US Government)
FORECAST 7 DAY RAINFALL FOR REST OF JUNE
ABOVE – GFS (America)
BELOW – ECMWF (Europe)
– WeatherWatch.co.nz Rural