The Radio Network’s Weather Watch Centre has issued it’s first Storm Alert for Spring as a low looks set to bring gales and heavy rain to a number of populated areas across northern and central New Zealand tomorrow.
At least 3 fronts will cross New Zealand over the coming 48 hours bringing heavy rain to western and northern regions and severe gales over a number of North Island areas.
“The main difference between this storm and other storms so far this Spring is the fact that it’s going to affect a number of populated places. The gales won’t simply be confined to remote regions. Major cities and harbours such as Auckland and Wellington are both in the firing line” says Head Weather Analyst Philip Duncan.
Mr Duncan says the strongest winds will be throughout Tuesday starting in the morning over central New Zealand and heading north into the afternoon. “Areas to the east of any hills or ranges will be most exposed to the gales. Eastern Coromandel, western Bay of Plenty, Gisborne, Hawkes Bay, Wairarapa, Wellington and Marlborough”.
Parts of Auckland may also see strong gusts well over 100km/h. “Western parts of Auckland close to the Waitakere Ranges or Manukau Heads may experience gusts to 150km/h thankfully few people live out there however the wind tunnel effect on highrise buildings in central Auckland may produce localised gusts over 130km/h and we’re advising pedestrians and cyclists to take extreme care in downtown Auckland tomorrow”. Strong winds may also disrupt travel plans across our largest city with severe gales possibly affecting traffic over the Auckland Harbour bridge and ferries across the harbour and Gulf.
Mr Duncan says due to Auckland’s large size not all suburbs may be affected by the gales.
The Weather Watch Centre also predicts hurricane force winds of 150km/h may pose a serious driving hazard on high altitude roads such as the Rimutaka Ranges and the Napier Taupo highway. The Desert Road may also be affected by severe gales. For road conditions click here.
Oddly the South Island won’t be receiving the nor’westers tomorrow. “Basically the centre of the low will pass over the South Island so it should be generally calm over much of the South, only northern regions will receive the winds tomorrow”. But Mr Duncan says by Wednesday all of New Zealand will be in a “strong westerly flow”.
Heavy rain is likely to be the main concern for most western regions tomorrow. “With heavy rain being driven in from the west it will likely build up against ranges to the east”.
Government forecaster MetService has issued 20 severe weather warnings for New Zealand. MetService says with the combination of rain and wind there’s a potential for damage to powerlines, trees and roofs.
The windy, wet, weather isn’t expected to ease until the end of the week – possibly a bit too late for those enjoying the last week of the school holidays.
on 6/10/2008 7:33am
Hi Phil, what’s a rough estimate of the average wind speeds on the Manukau Heads tomorrow afternoon. I saw you mention 150km/h gusts.
on 6/10/2008 8:26am
MetService predict winds of 120km/h possible in Auckland city – so gusts of 150/160km/h are possible on the Manukau Heads…all depends on the angle but anything from the west is good! Average wind speed probably fluctuating between 70 to 100km/h mark I’d guess.
During the weekend it was gusting to 60km/h at Auckland Airport and 120km/h on the Heads – which aren’t that far from the airport really, so it shows just how intense that "funnel" action can be.
on 6/10/2008 3:33am
Metservice has issued a high Thunderstorm risk for Canterbury for Tues arvo.Its predicting winds gusts of 90kmph,why do Thunderstorms create that much wind?
on 6/10/2008 5:11am
Hi there – basically the conditions that create these thunderstorms are very unstable and volatile. The showers become heavy and squally and they create something called wind shear, which is basically a small area of very strong wind – I usually refer to it as a ‘wall of wind’. The media often call them "mini tornadoes" because they can partially lift roofs but that term isn’t technically correct (although I have to admit I’ve used that term before!).
So basically it’s simply a burst of air that comes out of these large, unstable clouds. You might have trees damaged in one place and 1km down the road it’s sunny with no wind at all.
Hope that’s of some help! You can find far more detailed explanations here.