By Phil Duncan, WeatherWatch
First column of the year and if you’re reading this at the start of the week there’s a chance of rain across New Zealand today as a cold front moves in.
January has been far more summer-like than many may have predicted late last year. Despite rain, thunderstorms and drizzle, there have been some vary large and settled periods of weather.
New Zealand’s soil moisture map at the moment looks like Swiss cheese with “holes” here and there of dry and wet zones. Despite El Niño being here, globally there are other things at play impacting our weather.
One of the reasons I love my job so much is that despite historical data giving us some ideas of how the weather unfolds, it regularly surprises us.
This year, despite El Niño being well established, the extra marine and atmospheric warmth (on top of low pressure being stuck near Sydney for months) is making this like a Weather World Cup in which all the teams are playing well and it’s hard to pick the winner.
They are all there and making an effort. El Niño is winning overall, it’s the biggest player. But the low pressure zones and extra sub-tropical warmth near NZ are sure giving traditional El Niño weather patters a high pressure test.
I personally think the weather pattern we have this year over NZ is a great one – no such thing as a perfect forecast to suit all regions, mountain ranges, divides, businesses and gardeners, but I do believe summer so far is proving to be pretty good to us.
It’s been hot at times, but the low-pressure zone in the Tasman Sea has, for now, limited the amount of hot nor’westers we get out of Australia in El Niño (cooler lower South Island). High pressure has been further south in Australia, allowing for low pressure near Sydney and that’s created more easterlies and northerlies for northern NZ than we’d normally expect in El Niño, and in turn a few extra downpours / thunderstorms.
My feeling looking at the long-range maps is that this low pressure in the Tasman Sea, coupled with low pressure in the sub-tropics, will eventually break through to NZ. Meaning our long-range forecast going into February is one of chances of rain, mixed in with the dry. It’s a forecast that usually pleases most of you – but not all of you.
Who is leaning drier than usual soil-moisture-wise?
• Parts of Northland
• East Cape
• The lower North Island (from Hawera to Wellington)
• South Canterbury
• Central West Coast
Who is leaning wetter? (All North Island)
• The Far North
• Western Coastal Waikato
• Waitomo / King Country
• Central Plateau
• Monday January 15 kicks off with a cold front (between two high pressure zones to the east and west)
• Tuesday the next high from Australia moves in
• Wednesday sees a few isolated showers top of the North Island with easterlies
• Thursday/Friday brings a few isolated showers upper North Island
• This weekend: High pressure dominates
• Next week: Looks more unsettled for New Zealand