General November Weather

[mikestormchaser]

Wensday i am seeing a potential thunder/hail set up for coastal otago/canterbury..

[NZ Thunderstorm Soc]

Back to NW gales here at the moment.
I see that it is blowing a stiff easterly in town ?

[NZstorm]

Gusting to 44knots at Auckland Airport from WNW. El Nino weather getting worse for Auckland.

[Nev]

Report of a 'possible' tornado in Greymouth at about 5.25am this morn…

''Mini tornado' hits Greymouth' - NZ Herald

[melja]

Gale nw all day here in the mackenzie and getting stronger dispite the forecast of it calming down.
Cool to for a nw wind with only 17C , given it being mid Nov they just dont seem to be getting to there normal hotness yet

[David]

Gusting to 44knots at Auckland Airport from WNW. El Nino weather getting worse for Auckland.

We had gusts up to 59 km/h around 1pm, though it's not as gusty now.

[Brassnz]

Thunder here.

[spwill]

A squally downpour here and a loud clap of thunder, went through quick.

[NZstorm]

I was out for run and got caught in the thundery downpour. Grey Lynn recorded 6mm.

[Manukau heads obs]

Gusting to 44knots at Auckland Airport from WNW

this time the WNW wind was general across the area...and not just on the west coast here
(we got 50 knots here)

[NZstorm]

If you look at the model sounding for Auckland for 4pm you can see how much wind aloft there was today.

Also, I have placed the saturated adibat line trough the 850mb moisture to show some CAPE there. Just enough for thunder evidently.

[shovelopikis]

Large hailstorm out of nowhere on the 13th, for around 1min, 10 mins west of taupo, stones roughly 15-25mm and road was white within seconds, pulled over quickly to large embankment which provided a bit of safety from the wind direction, but alas, my brand new car has 3 big dents now

[Dale]

Can vouch for that possible tornado this morning Nev.. I was laying in bed & just on daybreak all hell broke loose outside, it had been teeming down rain a good hour already but the winds came up nearly as strong as TC-Ita over easter... really did think the roof was going to go for a few minutes. Too much in the la-la's to look out the window, probably just as well.

Explains why everything was flagged off around the Fire Station this morning......

[trickytiger]

Thought wind sounded and felt stronger than last year, although we only recorded a max gust of 91.8km/hr today... bit of damage around the place, lost a wall on the cow shed, 2 spans of our main pivot that runs the effluent flipped, broken power line across the driveway, power pole snapped at ground level on neighbours farm and a few trees down.

[Nev]

Can vouch for that possible tornado this morning Nev.. I was laying in bed & just on daybreak all hell broke loose outside, it had been teeming down rain a good hour already but the winds came up nearly as strong as TC-Ita over easter... really did think the roof was going to go for a few minutes. Too much in the la-la's to look out the window, probably just as well.

Explains why everything was flagged off around the Fire Station this morning......

Thanks for the report Dale. I see Greymouth Aero, which is just 1 km to the WSW, only recorded gusts to 65 km/h around that time, so the damaging winds must have been fairly localised. How far away are you from the fire-station, damaged garage?

TV3 also includes some footage in this clip.

[Nev]

For posterity, here's a list of some of the higher gusts affecting most of the country yesterday…

Code: Select all

Plus 85 km/h gusts for Nov 15 from MS's website:

172   Cape Turnagain
124   Darfield
124   Kaikoura
120   Le Bons Bay
120   Brothers Island
120   Kelburn, Wellington
120   Mamaku Radar
120   Golden Valley, Waihi
117   Dunedin Aero
117   Stephens Island
111   Wellington Aero
106   Lyttelton
106   Cape Campbell
104   Cape Kidnappers
104   Whangaparaoa
102   Culverden
102   Fairlie
102   Mahia Radar
100   White Island
98   Ohakea
96   Mana Island
94   Napier Aero
94   Hicks Bay
93   Ashburton Aero
91   Roxburgh
89   Whenuapai Aero
89   Waiouru
89   Invercargill Aero
87   Oamaru Aero
87   Paraparaumu Aero
85   Port Taharoa

Also some Canterbury PWS early morn gusts:

105   Eyrewell Forest
103   Barrhill
101   Amberley
91   Oxford 
91   Swannanoa
89   Methven

[NZstorm]

Interesting wind data there.

The trough comes across the top of the country like an express train tomorrow, moving very quickly. It's loaded with tropical moisture so brief heavy falls possible in the morning with the chance of elevated thunder for Auckland/Northland. The 850mb dewpoints are modeled at 11-12C which is more like what you would see in a moist situation in February.

[03Stormchaser]

Cheers for that Nev.

[Dale]

Thanks for the report Dale. I see Greymouth Aero, which is just 1 km to the WSW, only recorded gusts to 65 km/h around that time, so the damaging winds must have been fairly localised. How far away are you from the fire-station, damaged garage?

TV3 also includes some footage in this clip.

I live in Cobden right alongside the Grey River.. so to the Fire Station is about a 5 minute drive on a good day
Had to nip into town just before so went for a drive up to Cowper Street & sure enough, whatever it was that came through made a mess. The Greymouth Aero is about 1km down the road further so it would have been VERY localised.. but destructive, that old pine survived Ita & the other big winds of about 7 years ago.. finally gave up the ghost this time.

*EDIT* .. So judging by the windspeed I estimated around here.. it came in from my direction running over the mouth of the Grey & straight up the main drag.. would have been a very narrow swathe but for he aero (Grey Base Hospital) to only get 65km/h.. was closing in on triple figures as it roared past here, whatever it was.

[Paul Mallinson]

Thanks for the report Dale. I see Greymouth Aero, which is just 1 km to the WSW, only recorded gusts to 65 km/h around that time, so the damaging winds must have been fairly localised. How far away are you from the fire-station, damaged garage?

TV3 also includes some footage in this clip.

I live in Cobden right alongside the Grey River.. so to the Fire Station is about a 5 minute drive on a good day
Had to nip into town just before so went for a drive up to Cowper Street & sure enough, whatever it was that came through made a mess. The Greymouth Aero is about 1km down the road further so it would have been VERY localised.. but destructive, that old pine survived Ita & the other big winds of about 7 years ago.. finally gave up the ghost this time.

*EDIT* .. So judging by the windspeed I estimated around here.. it came in from my direction running over the mouth of the Grey & straight up the main drag.. would have been a very narrow swathe but for he aero (Grey Base Hospital) to only get 65km/h.. was closing in on triple figures as it roared past here, whatever it was.

These are very interesting comments. I am interested in this event because I have put together some guidance here that helps to identify wind storm situations whether they be tornadic or straight line winds.

What we saw in the guidance was:
very high Environmental and Storm Relative Helicities
LI w.r.t. 700 hPa was negative
0-1km and 0-2km bulk shears were 29 and 34kts respectively
3km CAPE over 200 but deep CAPE no more than 300 j/Kg (most in low levels
strong convergence on front
strong ascent on front

These are sufficient to indicate a small tornado but by the same token it may have been straight line wind damage??

There was a comment in the Greymouth Star by fireman John Walton who said...

"Just a massive wind, a strong strong wind. Then it just stopped".
"It only went for about five minutes, not even that really. It had been building up, but this wind was just phenomenal."
The wind snapped the top off the Norfolk pine at the back of the station and threw it into a brick wall, yet a stack of chairs less than 10m away had not even budged, he said.

I thought the comment about the chairs was interesting. It perhaps suggests a very confined event which might be the work of a small funnel? There was one or two lightning strikes around, but they were probably a little to the north.

I need to look at the radar data more carefully.

Paul

[Dale]

We had a couple of lightning strikes earlier this morning Paul.. cant give you a time but it was early morning. From what I have seen it was extremely localised but I have seen this around here.. you only have to look at the Blaketown Tornado (waterspout) of a couple of months ago which tracked along a very similar path & again I witnessed.. from my best estimations it was a relatively isolated event but for reference, as the straight line runs from my place to the Grey Fire Station is within 2kms.. I didn't notice any other damage through the direct area between, it's a path I normally drive to that side of town.

Where Cowper Street & the Fire Station is, both are elevated as opposed to the main drag through Greymouth, not sure if that would have some influence.?

[Dale]

Between you & me, I think it was more an isolated microburst.. the rain & hail at the time were pretty intense.

[NZstorm]

RE possible Greymouth tornado

I had a look at this yesterday and decided on balance it was a gust. But it was a highly sheared moist environment so a tornado was defintely possible.

[Manukau heads obs]

looks like lightning active CB's blowing up on the cold front (behind the warm front over northland)
heading our way

[spwill]

Lightning tracker