By Phil Duncan, WeatherWatch
The North Island storms so far this year have been relentless. Cyclones Hale and Gabrielle, the squash zone event that flooded Auckland on January 27, and others, then more flash flooding in the past seven days. Now we’re seeing March kick off with a (likely temporary) pattern change – with longer and larger dry spells coming into the North Island, bring with it some relief.
La Niña is likely finished this month. The Bureau of Meteorology out of Australia says indicators show La Niña is continuing to ease, even though it has taken nearly two months longer than originally expected.
But just because it’s fading doesn’t mean a major change is coming. It’s a bit of one step forwards and one step backwards as we see La Niña easing but at the same time the cyclone season peaks … so, put simply, we may not notice the change for another couple of months.
As La Niña fades we’re also seeing more energy from the Southern Ocean (normal for this time of year to see weather systems “waking up” south of New Zealand). This has been evident in southern and eastern areas having a colder southerly change coming in each week. We see more of that coming up – and still plenty of summer-like warmth in the mix, too. Some of those southerlies may contribute to rain in the eastern North Island – and not all of it will be heavy tropical storms; some of it may just be your typical wet southerly moving through.
Long range, we’re seeing a lot of low pressure remain in the tropics for the next two months –and while we’re also seeing a good mixture of high pressure zones coming into NZ too, the risk in between highs for a tropical or sub-tropical rainmaker is elevated. Hopefully the worst is behind us, but we can’t rule out future heavy rain heading down to NZ from the north.
Elsewhere, those in Southland and Otago have seen further relief, but very hit and miss. The drought/big dry in some parts of southern NZ may ease for some in the coming month, due to the Southern Ocean becoming more active (or put another way, becoming more “autumnal” – what a great word!).
Long range into winter, Southland and Otago may not see a huge amount of rain to return things to normal, so be prepared for the dry to linger for longer in some locations.
• Temperatures lift in Southland following a cool weekend
• Apart from a few showers on March 6, Hawke’s Bay and Gisborne have more dry weather coming
• Northland, Auckland and Waikato look to lean drier than average for the first half of March
• Still plenty of hot days in the mix for inland areas
• Southern Ocean showing more signs of life
• Tropics remain active this month and likely in April too
• Generally speaking, northern NZ looks to lean 0.5degC warmer than normal in March, and southern NZ heading for 1.1degC warmer than average