Moist NW flow and severe weather, Upper NI, 5 Dec -

GraemeWi · Unread post by **GraemeWi** » Thu 06/12/2012 18:16

03Stormchaser wrote:Trying to work out if this is related to the one that hit Hobsonville or another completely seperate tornado/waterspout as it appears over water here.

I'd say it would not be the same - approx 18 KM out to the east of the track

Willoughby · Unread post by **Willoughby** » Thu 06/12/2012 18:16

The Metservice is officially calling the Auckland storm a tornado.

The service said they received a reliable report from police of a tornado crossing the north western motorway.

The highest windspeed recorded at Whenuapai airbase, close to the time of the tornado, was 69 knots (110 kph). That constituted a severe gale but would not have been the speed in the tornado itself, which was not measured.

"Police Superintendent Bill Searle said a series of tornadoes passed through Hobsonville, and one of those touched down on a subdivision, causing damage to trees and buildings".

Source: unknown, sorry!

This photo here looks like a tornado with a wrapping wall cloud and a bit of an RFD cut!
http://images.tvnz.co.nz/tvnz_images/na ... and_E1.jpg

Manukau heads obs · Thu 06/12/2012 18:25

I notice Mercer had 65mm is a short space of time on the EW site.

that fits with my brother recording 60mm (in about 30 minutes) in Ramarama (just northwest of Bombay)

C-Nimbus · Unread post by **C-Nimbus** » Thu 06/12/2012 18:31

terrible news this, 3 deaths and a significant number injured.

With this in mind what will these be classed as on the F scale?

I'm thinking it could be F2 - F3??

Vertigo · Unread post by **Vertigo** » Thu 06/12/2012 18:54

im getting the feeling from the widespread tornado-like damage that this might be an outbreak of many tornados...

RODALCO · Unread post by **RODALCO** » Thu 06/12/2012 18:55

Great photo, I observed part of the wall clouds of the super cell in the distance from Browns Bay.
Very threatening dark grey clouds.
Pity I didn't have a camera handy.
Interesting to note that there are not more actual photo's of the event.

spwill · Unread post by **spwill** » Thu 06/12/2012 19:43

A few more photos of wind damage at Hobsonville.

NZstorm · Unread post by **NZstorm** » Thu 06/12/2012 20:36

The clip here that was tv

http://www.youtube.com/watch?v=mu_7lwX-GvI

Michael · Unread post by **Michael** » Thu 06/12/2012 20:42

We got lightning and thunder then about 2 hours of heavy rain followed,very ominous it looked before it began about 12 oclock.

Manukau heads obs · Thu 06/12/2012 21:03

Great video that
Looks up to 80kts!
Amazing how it suddenly damped up with sudden white out rain
That will be when the rain wrapped tornadoe passed by

03Stormchaser · Unread post by **03Stormchaser** » Thu 06/12/2012 22:23

Interesting one today, I think ive gone from its a tornado too there wasnt one too what appears like a tornado 'outbreak' if you can call it that. Appears there may have been three from,what I can gather.

spwill · Unread post by **spwill** » Thu 06/12/2012 22:43

A tornado can be seen in this clip, NZ Herald
http://www.nzherald.co.nz/national/news ... _id=129676

littleheaven · Unread post by **littleheaven** » Thu 06/12/2012 22:53

Not long after the tornado, what looked like the edge of a shelf cloud came over the hillside (the hill between my house and the inlet that separates us from Hobsonville/Greenhithe) and the whole thing was rotating. You could clearly see the low band of dark grey cloud, like a conveyor belt.

When the 2nd band of storms came through, I observed a large piece of debris flying over the treetops on top of the hill, just before the torrential rain hit. Apparently a tree fell on a car at Glenfield College, which is about 500-600m from my house. I suspect it happened when that squall went through. There was also a loud crack from the neighbour's house, indicating something had blown loose from their deck. We also had a very close lightning strike.

I had a builder here who was constucting me a storage room beneath the house. It's windowless and right between the big foundation poles for the house. I commented just the other day that it would make a good tornado shelter. We both hid in it for a while. The new drains to divert the water away from it worked superbly. It was an excellent test. The gutters were overflowing and water was cascading off the house.

jamie · Unread post by **jamie** » Thu 06/12/2012 23:10

spwill wrote:A tornado can be seen in this clip, NZ Herald
http://www.nzherald.co.nz/national/news ... _id=129676

oh nice one! I'm certainly leaning towards lots of little tornados occurred with one or two significant ones. I imagine there was a lot of RFD straight line wind damage too.

Some of the images are reminiscent of what I've whitnessed in USA

Manukau heads obs · Fri 07/12/2012 07:30

sounds like you were lucky littleheaven!
great video of the tornado their Spwill!

took this photo of incoming squall first thing this morning
with some nice structure

jamie · Unread post by **jamie** » Fri 07/12/2012 08:02

Yes there is some great structure to these cells floating around thismornig. Could be an interesting day.

Dale · Unread post by **Dale** » Fri 07/12/2012 09:07

Everyone is entitled to their own opinions on was it a tornado or not.. but I'm sorry, straight line winds, do not do this.

http://twitter.com/TroyRF/status/276759 ... 14/photo/1

Vertigo · Unread post by **Vertigo** » Fri 07/12/2012 09:32

definitely looks to me like we had multiple tornados around the greenhithe/hobsonville/whenuapai/westgate area. i might start working on a map of the locations of tornado like damage soon.

Manukau heads obs · Fri 07/12/2012 10:45

Will be the same one,touching down at times,should
Be a line nw to se
?

littleheaven · Unread post by **littleheaven** » Fri 07/12/2012 12:22

Dale Small wrote:Everyone is entitled to their own opinions on was it a tornado or not.. but I'm sorry, straight line winds, do not do this.

http://twitter.com/TroyRF/status/276759 ... 14/photo/1

I do agree a lot of the tree damage looks tornadic - leaves and branches stripped in what appears to be an upwards fashion, also the scatter pattern of the branches is very random rather than all in one direction. Eye witness reports talk of wind coming from one direction then another. And of course there are photos and video of funnels in the area. That's all good evidence to support the theory.

Dale · Unread post by **Dale** » Fri 07/12/2012 15:02

The way that massive tree was twisted off at the top, draw your own conclusions. It takes a hell of a lot of force to do something like that. 220km/h winds have been "guesstimated" with one of the tornados.. if you wanted to be really pedantic, that would put it in the EF3 category, as 3 second minima gusts of 218km/h.. but 220 sustained? Feeling for you lot up there right now.

Vertigo · Unread post by **Vertigo** » Fri 07/12/2012 15:03

Manukau heads obs wrote:Will be the same one,touching down at times,should
Be a line nw to se
?

the whenuapai and hobsonville damage is in the right line, but westgate is way to the SW.
the damage at hobsonville primary school that was reported is also too far away to be the same tornado.

Philip Duncan · Unread post by **Philip Duncan** » Fri 07/12/2012 15:26

MetService says it was a "mini tornado". Good grief.

Manukau heads obs · Fri 07/12/2012 15:31

nothing mini about 238 houses with damage, 150 with lots of damage and some completly flattened!!!!!!!!!

Manukau heads obs · Fri 07/12/2012 15:52

You know, M/S included a high risk of thunderstorms for the auckland area at 10:30am
as it started to show up on the lightning tracker and rain radar to the NW
that was great
but somehow they took their eye off the ball....
the CB never got a watch put on it...it should have...by 11:30 it was going off, just off the west coast...I could not understand at that time why there was not at least a watch put on it
At 11:30am I was so worried about it I phoned the local primary school to let them know a thunderstorm was about to hit...as it was going to hit right on lunch break, when the kids would have been out playing..

One problem is that as it moved over the land, it did weaken a little...as they often do..
but it then intensified quickly after 12:00, as it got the fresh NE in flow, which was morning sun heated and super saturated as well, moving in over the Waitemata harbour...so there was not alot of time to get a full warning out ...but still there was a chance by the 2nd rain radar scan to do exactly that....
(the full warning did not come out until 1pm)

so mayb e a review could be done on how things could be improved further...

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