NZ Weather Forum

But will these severe gales reach Chch? Sometimes, thankfully we miss out when damaging norwesters batter the inland plains and foothills.

Manukau heads obs wrote:actually wind strength is a square function due to F=MA2
and so at that speed, 10 kmh increase in windspeed is alot more damaging that just that 10kmh speed

Wrong formula though, F = ma is one of the laws of motion.
But indeed the wind pressure acting on an object is proportional to the square of the wind speed. See http://projects.knmi.nl/hydra/faq/press.html

what I was getting at , is that accelaration, in the formula, F=MA, is a square function, as you have pointed out

Those cb's along coastal Southland tomorrow could pack a real wind punch given 850mb winds are progged to be 70knots.
We don't often see such strong winds in association with convection in NZ. Southland is well acclimatised to strong wind though.

This update has it back at 160 this arvo...

AREA/S AFFECTED: CANTERBURY
FORECAST:
Severe northwest gales gusting 160 km/h or possibly more in exposed
places and especially the High Country, from around midday Sunday
until Sunday night.

tich wrote:But will these severe gales reach Chch? Sometimes, thankfully we miss out when damaging norwesters batter the inland plains and foothills.

I think when we get NW wind flows as strong as this one, often the coastal areas get hit as much as inland, but they can still be hit&miss, take the Sep last years blow, from Culverden to Waikari and out to the coast didnt get much damage but either side did.

Judging by the NW angle and the general topographical effect of the high country/southern alps inconjunction with previous strong NW systems,the worst areas hit should be north canterbury especially higher up but also along the coastline.
Maybe touching 120kmh there on the coast and 130+ inland, 90-100kmh through the city for a brief spell.
But its very hard to tell with these systems one shift in isobars and it goes nuts out east as well.

Still calm and warm in this part of the MacKenzie country.

No mention of damaging winds on MetService's short forecast for Canterbury tomorrow?

....anyway, don't want them, no more trees down please (got enough firewood here) and the chook-house better not roll as we have some baby chicks in it. Also I don't want my Stevenson's Screen to take another battering again, THANK YOU .

Wind here now and sky looks very dusty up Mt cook way, very warm wind too for this time of year.

Dunedin currently 22, Kaikoura 12 and apparently sunny.

24C in Twizel according to MS and 25 here at the lake, wind really getting wound up now.
25C in Oamaru now.

NZ Thunderstorm Soc wrote: Also I don't want my Stevenson's Screen to take another battering again, THANK YOU .

I reckon your Stevenson's Screen deserves some kind of resurrection John ...hey ...maybe we could organize a few afternoon brews after sticking her up on some fence posts.

Windy here - regular nor'wester windy

Had a thoroughly wonderful day tramping around the hills above Castle Hill Village today. Magic day, no drama with winds arriving so far. Was starting to pick up a bit though across the plains as we came home around 6pm

Its mild out now 15c with a breezy NW, its 8c at christchurch airport so NW hasn't made it there yet.
Its been a keen NE this afternoon ahead of the incoming NW, but not the bitter Easterly of a week ago.

Wind is not as strong now as it was during the night when there was some very big gusts.

Calm most of the night down here, very warm still and a light breeze now.

MS saying 120km for chch. Might head up port hills later on

03Stormchaser wrote:MS saying 120km for chch. Might head up port hills later on

Take a stunt kite!

Growler wrote:

03Stormchaser wrote:MS saying 120km for chch. Might head up port hills later on

Take a stunt kite!

I'll be up there for a run

I'll be up there for a run

You'll be up there for a fly!

Gusts to 102k in Gore

the Wairarapa, e.g Castle Point/Cape Turnagain, is the windiest place currently ..gusts to 70knots (145kmh)
(not unusual for those places...its a 'pressure release valve' there)
Parts of Otago been getting gusts to 45kts

Breeze has picked up noticeably here in the past twenty minutes. Now a noise of wind in the eaves or somewhere.