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Damaging winds 4/10/2015
Posted: Thu 01/10/2015 15:21
by Richard
A high risk of damaging wind for Sunday, as yet not saying max gust speeds are.
From the Met service
A very strong northwest flow is likely across the South Island during Sunday, with high confidence of severe northwest gales for exposed parts of Southland, Otago, Canterbury and Marlborough. These gales may be damaging in some inland places, with the potential to damage structures, power networks, and make outdoor activities and driving hazardous. Westerly gales spread to the lower and eastern North Island on Sunday and early Monday, where there is low to moderate confidence of severe gales as depicted on the chart.
Re: Damaging winds 4/10/2015
Posted: Thu 01/10/2015 15:59
by Bradley
They are saying 160kmh within the Metrsvice potentially
Re: Damaging winds 4/10/2015
Posted: Thu 01/10/2015 16:04
by Tornado Tim
I would usually use the Beaufort scale: Severe Gale: 74.6–88.1km/hr but I wouldn't put it past the meaning of Damaging Severe Gale could mean 90km/hr+
Re: Damaging winds 4/10/2015
Posted: Thu 01/10/2015 21:25
by NZstorm
Gfs indicating peak gusts of 80knots (150km/h) Southland to Canterbury.
Also spill over thunderstorms for inland Otago.
Re: Damaging winds 4/10/2015
Posted: Thu 01/10/2015 21:37
by NZ Thunderstorm Soc
We don't want anymore damaging winds here, got enough firewood from the Big blow of September 2013.
...probably wont be that windy anyway.
Damaging winds 4/10/2015
Posted: Thu 01/10/2015 22:11
by Tornado Tim
Quite a sting in Sub Antarctic Jet Forecast on Tuesday AM next week, Forecast of 130 to 140 knots at 300 Hpa according to NCEP, GFS. EC has a similar timing with a similar forecast around that time.
Re: Damaging winds 4/10/2015
Posted: Thu 01/10/2015 22:18
by Bradley
[quote="NZstorm"]Gfs indicating peak gusts of 80knots (150km/h) Southland to Canterbury.
Yes though it looks in the latest model run with EC peak gusts have downgraded a little, here's hoping it keeps going that way!
Posted: Fri 02/10/2015 04:08
by melja
Will be in the McKenzie country this weekend so will see how windy it is.
Re: Damaging winds 4/10/2015
Posted: Fri 02/10/2015 05:15
by Nev
Mod Note: Just a reminder that personal attacks won't be tolerated here!
So any further similar comments will simply be deleted.
Re: Damaging winds 4/10/2015
Posted: Fri 02/10/2015 10:49
by Bradley
Unfortunately it looks like this could be quite a big wind event for eastern areas of the South Island, hopefully a couple of the farmers have learnt from the big blow in September 2013 and move their irrigators to face the correct direction this time.
Here's the latest from the Metservice:
AREA/S AFFECTED
Canterbury
FORECAST
Severe northwest gales gusting 160 km/h or possibly more in exposed places, especially the High Country, from early Sunday afternoon until Sunday night.
Posted: Fri 02/10/2015 14:18
by melja
Not up waiau , there all side on at this stage.
Re: Damaging winds 4/10/2015
Posted: Fri 02/10/2015 14:24
by Bradley
I'd say I saw at least 4 big irrigators blown down in that September event around the Darfield, Coalgate area, hopefully they all plan to move them tomorrow at the latest, even if it all comes to nothing it will better to be safe then sorry...
Re: Damaging winds 4/10/2015
Posted: Fri 02/10/2015 15:31
by Storm Struck
I wonder if this NW belt airstream will change to a more SW or southerly belt in a few weeks time, would certainly be more favourable for eastern SI storms.
If its more westerly then this El Nino might not produce many thunder days at all especially in Canterbury.
Or am I just far too impatient
Re: Damaging winds 4/10/2015
Posted: Fri 02/10/2015 16:40
by Bradley
From the Hurunui District Council warning centre:
Winds are forecast to be of a similar strength to the September 2013 wind storm which caused widespread damage throughout Mid and North Canterbury. Winds of this strength could damage trees, bring down powerlines and lift roofs, as well as make travel hazardous.
Re: Damaging winds 4/10/2015
Posted: Sat 03/10/2015 01:51
by Karliosis
It will be interesting to see to what extent the pressure drops in Canterbury on Sunday. GFS (06z Friday) shows about a 15hPa drop between 00z and 06z Sunday, but sometimes with these intense fohn systems the pressure locally drops lower than models estimate. I might use my Kestrel to log the pressure on Sunday and post the resulting graph here if it turns out interesting
Re: Damaging winds 4/10/2015
Posted: Sat 03/10/2015 07:34
by NZstorm
I don't think it will be as strong as the 2013 event for Canterbury. But that doesn't mean it won't be severe!
Elevated lightning may come off the Alps into regions like MacKenzie.
Also isolated severe thunderstorms possible on Southland coast for wind gusts 70knots.
Posted: Sat 03/10/2015 08:14
by melja
Might take our caravan awning down just to be sure when we go home Sunday.
Calm and cold -4 here.
Re: Damaging winds 4/10/2015
Posted: Sat 03/10/2015 09:59
by Manukau heads obs
latest warnings have backed it off slightly, 150kmh gusts instead of 160kmh gusts
still I hope farmers with irrigators are storing them on an angle to catch the least amount of wind and away from the river beds
Posted: Sat 03/10/2015 10:04
by melja
It does say "or more" tho in the warning.
Driving down to Twizel I would say most in south Canterbury are away from the Nw but it was a different story yesterday in north Canterbury where I would say 80% were side on.
Re: Damaging winds 4/10/2015
Posted: Sat 03/10/2015 10:05
by Manukau heads obs
yes, but it did before, when the number was 160
Posted: Sat 03/10/2015 10:10
by melja
Oh well 160-150 much the same damage I would have thought
Re: Damaging winds 4/10/2015
Posted: Sat 03/10/2015 10:15
by Manukau heads obs
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
Posted: Sat 03/10/2015 10:23
by melja
Mmmm OK lol
Re: Damaging winds 4/10/2015
Posted: Sat 03/10/2015 10:31
by Bradley
Still says 160kmh for Canterbury
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.
Re: Damaging winds 4/10/2015
Posted: Sat 03/10/2015 10:33
by Manukau heads obs
yeah, i see that now...maybe that should have been mentioned in the summary at the start