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

[NZstorm]

I am currently doing a study of the event both onground and looking at the meteorology.

WAITNT wrote

but to call it a tornado when the evidence doesn't stack up just gets you into a discussion where your position is on sinking sand...

Make sure your defence of the Met Service does not get in the way of a scientific approach.

[Manukau heads obs]

looking forward to reading about your findings NZstorm

[Cook]

I am currently doing a study of the event both onground and looking at the meteorology.

WAITNT wrote

but to call it a tornado when the evidence doesn't stack up just gets you into a discussion where your position is on sinking sand...

Make sure your defence of the Met Service does not get in the way of a scientific approach.

Even thought the facts seem to show a certain agency that claimed to have forecast a tornado and then bragged about this forecast in a poor light I don't really see how what WAITNT says is a defense of the MetService. Of course, banging ones breast and claiming that one forecast something, after the fact, and then it turns out that it did not happen at all is not a good look, but we all make mistakes. It is hard to forecast the future if you don't even understand the past.

I wish we could express our interest in the weather in a constructive way and work together to understand it rather than let biases towards this group of forecasters or another get in the way.

[WIATNT]

This is the real political debate here...

"Another issue is that the MetService has locked up the New Zealand rain radar to ensure a profit goes to the Government. This denies other forecasters and, more importantly, the general public, access to high-resolution radar images. In the US, people can track dangerous thunderstorms - not the tornadoes but the thunderstorms - and it is clear where the severe weather is. High resolution radar means you can zoom in to your suburb, town or street to see how close it is."

http://www.nzherald.co.nz/nz/news/artic ... d=10852797

[Razor]

This is the real political debate here...

"Another issue is that the MetService has locked up the New Zealand rain radar to ensure a profit goes to the Government. This denies other forecasters and, more importantly, the general public, access to high-resolution radar images. In the US, people can track dangerous thunderstorms - not the tornadoes but the thunderstorms - and it is clear where the severe weather is. High resolution radar means you can zoom in to your suburb, town or street to see how close it is."

http://www.nzherald.co.nz/nz/news/artic ... d=10852797

Excellent- back on topic- the title of this thread is a severe weather one as many here have alluded to, not specifically tornadoes, or the like- the importance of having these things appropriately warned/ notified is vital

[WIATNT]

Here are video clips for comparison.

I notice Metservice have amended their blog today stating they now are of the opinion that it was not a tornado, but a severe microburst.

There updated blog does, however, have an error. They say that absence of evidence is not evidence of absence. They are totally wrong. Absence of evidence IS evidence of absence; what it is not is PROOF of absence.

Albany 2011
https://www.youtube.com/watch?v=Hqb5SDL8J5o
https://www.youtube.com/watch?v=UL_6XFhMwPk

AuckFeb 2012 waterspout
https://www.youtube.com/watch?v=LI-2nY4ZBg0
https://www.youtube.com/watch?v=Opj5VwHc4mM

Hobsonville
https://www.youtube.com/watch?feature=e ... dvUsTDTBPM
https://www.youtube.com/watch?v=f9CYQof-ZL8
https://www.youtube.com/watch?v=UbcxJ1fbDsM


https://www.youtube.com/watch?v=r0bL-GFr6UI

[Cook]

It gives me great pleasure to see that the MetService have taken another look at this. Perhaps some others might follow this example.

[Razor]

Hey Cook and WIATNT- just a note that you appear to take a degree of glee from being "right". This is not how we conduct ourselves here, it would be good if you could ease up a bit, your posts are repetitive and blimmin hard to fliter out among everyone elses as you keep reiterating the same comments with long and verbose prose.

Polite suggestion is if you want folk to read your comments, you need to be a bit more to the point, and alittle less condescending.

[TonyT]

I feel we have covered this ground pretty thoroughly in this thread, and we are starting to now go back over old ground and see who can shout the loudest. Please keep any future comments to new material or new interpretations. Failure to do so will test the moderators' patience to the point where we may lock the thread permanently.

[Razor]

I feel we have covered this ground pretty thoroughly in this thread, and we are starting to now go back over old ground and see who can shout the loudest. Please keep any future comments to new material or new interpretations. Failure to do so will test the moderators' patience to the point where we may lock the thread permanently.

Thanks

[Manukau heads obs]

the last video linked is not even looking towards west auckland, so not sure why that is there

the other videos (one of which was shown on the news on the day) show the straight line winds we know occured
with which there was an embedded tornado in those straight line winds

a CB producing severe straight line winds (microburst)
(with some of the worst damage seen in NZ)
did not even have a watch on it
that was the problem

in any case

note there is a video , which has been linked and discussed on this thread, of a tornado in the greenthithe (spelling ?) area
so it was a tornadic CB line as well as one producing a microburst

[WIATNT]

I wonder if Philip Duncan is still 90/10 that it was a tornado or whether, a week on, he's now leaning toward his alternative, a severe microburst.

Remember, forecasting is wrapped around credibility. Several hours after the event Philip was on video/tv saying that it had not been confirmed as a tornado... it still hasn't. Metservice has at least critically evaluated the evidence and back-tracked. That, to me, enhances their credibility, not diminishes it.

Philip, having the benefit of a weeks review of the evidence, can you perhaps update us on your expert opinion?

[WIATNT]

Manukau heads obs, there was no tornado reported in Greenhithe... at best it was a whirlwind...

[NZstorm]

I would like to see a proper study done on this event.

Obviously the Met Service have already done their analysis and I am looking forward to reading the scientifc basis on which they have made their conclusions.

[Manukau heads obs]

there was no tornado reported in Greenhithe

the video shown , shows a tornado (short lived)
whirlwinds do not have condensation cloud..


why is what Phillip Duncan said got anything to do with all this ?

Metservice has at least critically evaluated the evidence and back-tracked

by looking at some stuff online?

have they actually gone to ground zero and checked on the evidence themselves?

are you guys involved someway with Met Service?

[NZstorm]

Manukau heads obs, there was no tornado reported in Greenhithe... at best it was a whirlwind...

The Greenhithe clip shows a tornado. The person doing the filming has pointed the camera in that direction for a reason.
Many tornadoes are multivortex and I get the impression that's what the person was recording.

[NZstorm]

Just add for people who don't know Auckland's Geography, Greenhithe and Hobsonville are more or less the same place. Right next door to each other.

[jamie]

Manukau heads obs, there was no tornado reported in Greenhithe... at best it was a whirlwind...

you have already stated you have no interest in the weather, so how can you look at the video and be of power to say its a whirl wind?

Its clearly a tornado

[WIATNT]

Greenhithe is at least 2km away from where the men were killed at it's closest point... across a harbour...

It's starts in the top right of this snip...
http://www.weatherforum.org.nz/phpBB3/d ... &mode=view

Whatever it was in greenhithe, that isn't what went through whenuapai and hobsonville... a distance of some 4km long and 500m wide. Would a tornado be able to travel that far and damage an area so wide without being seen?

The absence of evidence certainly is strange in todays world with every other person carrying a video camera... even still camera.

Re why ask Philip Duncan? Well three reasons. One, he's contributed on here, two, he is claimed to have predicted a tornado (actually, he didn't, he stated a low probability of one occuring. On the balance of probabilities, he in fact said it was not very likely that their would be one.) and thirdly, several contributors on here seem to be involved with weatherwatch.

For the record, I am Joe Average with no involvement whatever with Metservice.

Also for teh record, WIATNT was coined from, When Is a Tornado Not [a] Tornado? Missed adding the last A.

I'm done here. I had googled, "was it a tornado" and "hobsonville"... this was the only hit so I signed up to ask if anyone had actually seen a tornado, and had evidence of it. Absence of evidence certainly is evidence of absence. Until actual evidence shows up I've concluded it wasn't a tornado. Just a severe localised storm. If the technical term is a microburst, so beit.

Remember, credibility isn't just about being right... more often than not it's about how one responds when challenged by new evidence that is in-conflict with one's beliefs. It's OK to change one's mind in light of new evidence.

I'm done... you've answered my question. Thanks.

[spwill]

The Greenhithe clip shows a confirmed tornado so WeatherWatch were correct in their thinking for the day, atleast they alerted the public to a severe weather chance which more than MetService could do..

[kaimaikid]

It gives me great pleasure to see that the MetService have taken another look at this. Perhaps some others might follow this example.

I have been stirring this up on more than one occasion on ZB and gave PD a good chance to have a crack at the MS on air...

and besides there seems to be a lot of hot air coming from West Auckland at the mo... but not sure if you could class it as a extreme weather event as it seems to be fairly constant since around November, one could almost be suspicious that the cause of all this hot air isn't a MS employee

[NZ Thunderstorm Soc]

There were 16 of them that discussed the fromallions of the surrender to the durrnace that was paid to the survivors of the inferno. The tornado had the cooliage effect of the understanding of the forecast done for the period. Upper atmosphere reading by comparison showed 4.5 at the 500 hPa level.
What touched the ground was what they call the "Swiffling" effect that comes with the sudden movement of air within a 'air-subsidence twist'.
Air movement from such systems can be hard to predict, actually impossible, even using the Fedwol forecasting model which can forecast predictions even before they happen.

[Orion]

Oh awesome! Thankyou!

[Tornado Tim]

OK first of two points:

Tornado vs Microburst:
I personally had doubts if it was a tornado or not, going by the footage provided, but then again I wasn't there.
The quality of evidence to prove that it was Tornado isn't exactly solid, more investigation needs to be done.

The two theory's provided: Severe Microburst vs Tornado are completely different and develop at completely different stages of a Thunderstorm.
Therefor, it has got to be said that the 2 can't occur at the same time.
So in order to go through this completely and throughly date's and locations need to be listed on the evidence (Photo's and videos).
Media Organization's usually take anything they can get so photo's and videos do need to be criticized if there is going to be a fair investigation.

It is still possible that a Tornado and Severe Microburst occurred, however its extremely unlikely that they would occur at the same time. I remember a relatively keen NE kept the front at bay and fairly stationary for a time.
This could of held the storm in place, allowing for the storm to cycle within a short distance and therefor produce both kinds of weather phenomena. However this needs to be proved and is just a theory.

Metservices Warning's or lack thereof:
First of all, I want to state that I don't dislike the Metservice.
NZ is a hard place to forecast for.
However, there was a lack of Warning on this storm, irrespective of Tornado vs Microburst it still contained strong wind.
When this wind was able to be detected by equipment from Metservice is still yet to be seen.

Since the team at Metservice are Human, like us are bound to make mistakes at some point.
If Metservice have come to the conclusion that a mistake was made about the warning of this storm, I hope they would come forward and admit it, for the benefit of the public, the family's involved and their own internal team.
Investigations on this storm should be made, this will help with the forecasting and tracking of storm's when a similar situation is encountered later on.

This event has truly outlined what is lacking when it comes to the NZ Metservice & NZ Government.
Some thing's such as radar resolution and data withholding can't be solely blamed on the Metservice.
Since they are an SOE (State Owned Enterprise), they have to make a profit.

The money the Government pays Metservice (for Meteorological data) is not enough, that is why the public is being starved of data.

I surely hope this event helps the public cause and forces the NZ Government to do something about it.

[tgsnoopy]

OK first of two points:

Tornado vs Microburst:
I personally had doubts if it was a tornado or not, going by the footage provided, but then again I wasn't there.
The quality of evidence to prove that it was Tornado isn't exactly solid, more investigation needs to be done.

The two theory's provided: Severe Microburst vs Tornado are completely different and develop at completely different stages of a Thunderstorm.
Therefor, it has got to be said that the 2 can't occur at the same time.
So in order to go through this completely and throughly date's and locations need to be listed on the evidence (Photo's and videos).
Media Organization's usually take anything they can get so photo's and videos do need to be criticized if there is going to be a fair investigation.

It is still possible that a Tornado and Severe Microburst occurred, however its extremely unlikely that they would occur at the same time. I remember a relatively keen NE kept the front at bay and fairly stationary for a time.
This could of held the storm in place, allowing for the storm to cycle within a short distance and therefor produce both kinds of weather phenomena. However this needs to be proved and is just a theory.

Metservices Warning's or lack thereof:
First of all, I wan't to state that I don't dislike the Metservice.
NZ is a hard place to forecast for.
However, there was a lack of Warning on this storm, irrespective of Tornado vs Microburst it still contained strong wind.
When this wind was able to be detected by equipment from Metservice is still yet to be seen.

Since the team at Metservice are Human, like us are bound to make mistakes at some point.
If Metservice have come to the conclusion that a mistake was made about the warning of this storm, I hope they would come forward and admit it, for the benefit of the public, the family's involved and their own internal team.
Investigations on this storm should be made, this will help with the forecasting and tracking of storm's when a similar situation is encountered later on.

This event has truly outlined what is lacking when it comes to the NZ Metservice & NZ Government.
Some thing's such as radar resolution and data withholding can't be solely blamed on the Metservice.
Since they are an SOE (State Owned Enterprise), they have to make a profit.

The money the Government pays Metservice (for Meteorological data) is not enough, that is why the public is being starved of data.

I surely hope this event helps the public cause and forces the NZ Government to do something about it.

Thank you Tim, one of the best posts to date on this topic.