Severe NW gales - Eastern SI, lower NI - Nov 2-3

[matttbs]

I think it's worth making a topic on this as metservice have upped their original warning from 140kmph to 160kmph for the plains close to the foothills. That's bloody mental. Seems as this one is going to hit a few places. Friend up in Glenrock is experiencing strongest wind in the 8 years he's lived there. 150m visibility due to dust. Not sure on the actual speed though. Currently 50kmph gusting 72kmph here

[Bradley]

Barely any wind here in west Melton or the city (also a friend in Sheffield reporting only moderate gusts as well) where there is at most gusts of 50kmh. I wonder when the Metservice expect these winds to become severe for central Canterbury?

[matttbs]

I was thinking the same thing, it was building but then it's dropped off completely! I'm beggining to think the worst has passed and nowhere near 160kmph

[tich]

Northwesterly very strong to near gale in Akaroa. Scrub fires at Okains Bay and Governors Bay.

[melja]

Light breeze most of the day in Rangiora.

[Bradley]

I'd say the Metservice were off by about 100kmh for the maximum gusts for inland central Canterbury. Sorry but I just don't trust the Metservice warnings for wind in Canterbury now, they have been way off in their forecasts the last 4 out of 6 times.

[Dean.]

Thought the warnings were pretty good actually,many inland places copped extreme winds.A campervan toppled over at Mt Cook trapping those inside.Many road cautions throughout inland Canterbury on the AA website.Some strong to gale gusts here in town today.

[Bradley]

Darfield, West Melton, Sheffield and Oxford all didn't record any gusts over 60-70kmh, I'd say that's a pretty good representation of inland central Canterbury

[Dean.]

Ahh well after the past few years its better to be safe than sorry,northwest gales don't always touch down in all areas.

[Dean.]

Darfield, West Melton, Sheffield and Oxford all didn't record any gusts over 60-70kmh, I'd say that's a pretty good representation of inland central Canterbury

Could throw a blanket over those four towns
Perhaps Twizel,Mt Somers,Loburn and Hanmer would be a better example for Canterbury in general.


SH 73 Arthurs Pass To Springfield Caution Strong Winds. Extra Care Required, Especially For High Sided Vehicles And Motorcycles. N/a 2 Nov 2014 08:59 Until further notice

[Bradley]

As I said in my first post I mentioned Central Inland Canterbury, last time I checked Hanmer isn't central Canterbury:)

[Nev]

Thought the warnings were pretty good actually,many inland places copped extreme winds.A campervan toppled over at Mt Cook trapping those inside.Many road cautions throughout inland Canterbury on the AA website.Some strong to gale gusts here in town today.

Mt Cook Aero was gusting around 180-200 km/h around the time that campervan was blown over late this morn. Also saw Kelburn, Wgtn recording gusts of at least 126 km/h earlier today.

[Dean.]

Metservice warnings were for inland Canterbury as I was referring too.
Anyway,its over now....move on

[Bradley]

Metservice warnings were for inland Canterbury as I was referring too.
Anyway,its over now....move on

Why are you still talking about it then?

[melja]

Well actually the warning goes like this.
"Expect severe northwest gales today, easing this evening. Wind gusts of 160 km/h are likely about exposed areas, especially about the High Country and the Plains close to the foothills where they could even be stronger."

So the warning was for the plains close to the foothills like Oxford and the others he said, went running for a few hours up in the Mt Gray Ashley forest area and bugger all wind really and the NEer is stronger sometimes.

[Razor]

Came over Porters Pass this arvo. Severe gales whipping up spray etc on Lakes Lyndon and Pearson. The warning was warranted

[melja]

Pukaki airport and Omarama max gust was 67kph and 63kph yesterday.

[Bradley]

Pukaki airport and Omarama max gust was 67kph and 63kph yesterday.

Thanks for that Melja, glad someone is actually looking at the facts! Farmers in particular in those areas deserve better then warnings that are 100kmh off the mark, no doubt plenty of preparation went into yesterday and keeping their machinery safe and sound...

[Nev]

I see MS's Le Bons Bay site (236m asl) recorded NW'ers up to 130km/h yesterday.

[Manukau heads obs]

come on guys
you all know the NW wind east of the Alps is a fickle thing
some areas will get it , some other areas will not
it all depends on how the wave formation forms (i.e where that touches down)
and where the pressure/release valves in the formation of the lee trough forms
Its not easy to forecast
and just because it was not windy at your place does not mean somewhere else was not getting it

[matttbs]

Can someone explain to me how I had just an average blow when I'm right up against the hills at 310m but then areas down towards the coast eg hinds had gales most of the day?? I did notice the clouds just overhead of me were racing through the sky

[RWood]

This nit-picking is ridiculous. The day when such a complex wind field can be predicted with an accuracy that would satisfy everyone will be in the days of practical quantum computing, most likely - far off. The real agenda is "bash the Met", I suspect. But I can imagine the howls of protest if worst-case scenarios weren't allowed in warnings, and many were caught unawares ...

[Manukau heads obs]

@mattbs
its all about the wave formation...the wind goes up and down...due to the ranges...
where it comes down you get a belt/band of gales
where it goes up you get lighter winds
those bands migrate too...they are not fixed...as the isobars move..i.e as the lee trough changes...i.e as the frequency of the wave changes too (sometimes there will be more or less waves in the sequence too as well as the position)
studies done on weed dispersal across the plains show that there are bands where this wind wave comes to the surface more often across the plains than other bands,..i.e there are places across the plains that get the NW gales more often than other places...but every NWer produces its own unique wave setup...there will be an average setup but there will also be exceptions to the rule
this is what makes the lee trough so interesting but also so hard to predict

[matttbs]

@mattbs
its all about the wave formation...the wind goes up and down...due to the ranges...
where it comes down you get a belt/band of gales
where it goes up you get lighter winds
those bands migrate too...they are not fixed...as the isobars move..i.e as the lee trough changes...i.e as the frequency of the wave changes too (sometimes there will be more or less waves in the sequence too as well as the position)
studies done on weed dispersal across the plains show that there are bands where this wind wave comes to the surface more often across the plains than other bands,..i.e there are places across the plains that get the NW gales more often than other places...but every NWer produces its own unique wave setup...there will be an average setup but there will also be exceptions to the rule
this is what makes the lee trough so interesting but also so hard to predict

Thanks for that, great explanation on how it works. It's actually blowing a gale here now but only light winds down the road so that is a very good indication on how much it varies with each passing NW

[Manukau heads obs]

I did some studies on the canty NWer when I was at Lincoln Uni back in the late 80's