NZ Weather Forum

NZstorm wrote:
My thinking on this event was that it was a mesovortex tornado.

I don't think the damage pattern is supporting the microburst theory, there is very little in the way of divergent damage pattern but rather the pattern has a convergent look to it, strongly convergent in places.

I still find it hard to believe that in such a historic weather event in NZ's biggest city that no wind velocity images have been released by the MetService when the technology is there and available.

It truly boggles the mind.

Edit: I've since made an OIA request with them.

Willoughby wrote:I still find it hard to believe that in such a historic weather event in NZ's biggest city that no wind velocity images have been released by the MetService when the technology is there and available.

It truly boggles the mind.

Edit: I've since made an OIA request with them.

Good! A while ago I complained to Tony Ryall(via my MP) and told him directly about the benefits of having the velocity images released (and other complaints I had).
I got given a letter back (around 2 pages) explaining metservices reasoning not to release these images to the public (these do not directly tie into the the Hobsonville Tornado).

I won't release this letter on the forum to the public, but If people want to see this letter just give me a PM.

Could it have been a derecho?

wembley wrote:Could it have been a derecho?

No Durecho's are classified as a Mesoscale Convective System which can cover hundreds of kilometres, this is more localised.
There is still debate on the feature that Durecho's and Storms can produce….. Strong Straight-line winds.

A microburst occurs when a storm cell collapses. Negative buoyancy develops and the air comes straight down at increasing speed and when the air hits the ground you get further accelerations.

A Drecho is more like a squall line, there is an organised linear system and the storm cell is not weakening.