Topic: Sydney waterspout footage

[nmoir]

check this great footage from ch7 in sydney

follow link and then look for twister story

http://au.news.yahoo.com/video/seven/index.html

[nmoir]

Watch it fold that roof in half and then suck it up and hurl it!

[Jimmy Deguara]

Nick,

Great piece of footage (if I could play it on my internet). After your call and one from Ray, I sat up and took notice! Anyone else see the footage/images?

Regards,

Jimmy Deguara

[Dave Nelson]

I recorded it of channel 2 news last nite  its an mpeg movie on my puter 
 I will clean it up and put on my www site
its going to be ~ 17mB in size ... hope you have broadband
I could make it smaller but that would loose quality

give me till mid saturday afternoon     
the quality will be substantially better than wat was on the channel 7 www site


cheers
Dave N

 

[Jimmy Deguara]

Hi Dave,

Place a link - as a file it is easier for those with snail speed internet!

Regards,

Jimmy Deguara

[Dave Nelson]

ok guys

 here's a link to a mid quality copy of the news item still better than the Ch7 site
beware its 18Mb in size

www.sydneystormcity.com/060804Waterspout.mpg

if you would like the original version   mail me  and I could put it on a CD for you
cheers
Dave N

[Geoff Thurtell]

Here is an AAP news item on the waterspout:

http://news.ninemsn.com.au/article.aspx?id=71675

Regards,
Geoff

[Geoff Thurtell]

Channel 7 replayed the footage on the news tonight, along with some extra footage of the damage. I managed to record this on video. Definitely a strong waterspout.
Geoff

[Seannmc]

I have some high def footage, can someone tell me how to put in a link for a file

[Harley Pearman]

Fridays storms

Good evening. The thunderstorms of Friday were unusual in my opinion in the following ways:-

I have never recorded a single thunderstorm occurring in August in Sydney since moving here in 1997 and my personal records do not show any storm occurring during this month. The earliest season storm I remember occurring since 1997 was around 3 September 1997 and 4 - 5 September 2004. This makes it unusual in this sense in that an August storm in Sydney is very rare.

I admit where I was (Auburn), the storms were producing mainly rain with the occasional rumble. I noted though looking through the BOM models and infra red pictures throughout the day that some cloud tops off the coast were reaching heights where the air temperature was -55 degrees. I place their heights at over 30 - 35,000 feet. Quite unusual I thought for this time of year because most CB clouds I have seen from aircraft top out at 7 to 8 KM high (June, July and August). The upper trough I though was strong. I looked at the 700 level on BOM and I have never seen the temperature at this level drop to -38 degrees over our region.

The heaviest concentration of storms and showers were off the coast and I noted at 5.20 am a single bolt lit up an entire CB cloud sitting off the coast. The radar showed it some 20 km off the coast at this time and moving NNE parallel to the coast.

I note that there was a water spout / tornado that crossed the coast at La Peruse. Did this form on the SE side of the storm and if so how? My understanding is that they would be found on the northern / NW side of the storm. My curiosity.

Do you realize that if this is a tornado, then there have been at least 5 weak tornados or similar in the Sydney region in 6 years (3 November 2003, 3 February 2005 and now this). Any discussion or thoughts on this (That I am aware of).

Looking at my weather records, I also note it really was the coldest day in 10 years, I think July 6 when the temperature reached around 10.4C. Another significant event.

I also note another significant event TO. It was the wettest August day in Blacktown since about 1999 based on the records I have. We had 28 mm. Penrith 15 mm Cronulla 89 mm clearly indicating it was more coastal but west of Blacktown rainfalls dropped sharply away.

Harley

[Jimmy Deguara]

Hi Harley,

Welcome to the forum.

Storms during August are not too uncommon and occasionally can be severe. I guess this is the turbulent period where cold fronts can interact with warming conditions

There were the possibility of storms on 27th August 2001 when an upp trough came through during the afternoon. Also the 1st August 2000, there was a storm or two around the better storm was near Wollongong. Then the 20th and 23rd August 2000 produced a few storms. There were storms in some suburbs on the 28th August.

Obviously the dates seem to be more biased towards latter August.

Regards,

Jimmy Deguara

[David C]

I note that there was a water spout / tornado that crossed the coast at La Peruse. Did this form on the SE side of the storm and if so how? My understanding is that they would be found on the northern / NW side of the storm. My curiosity.


Harley

Hi Harley,

Ray called me around the time and said that there was frequent Cg lightning in his area (south Hurstville) - we had a few rumbles here at North Ryde and the rain.

This was a tornado, no question. There were reports and, I think, photos supportive of a funnel cloud connecting with the cloud base ie the tornado was under an updraft (ie not a gustnado). 'Tornado' refers to a particular phenomenon [see the AMS Gossary] but the physical processes (certainly far from being fully understood) that produce different 'types' of tornadoes are almost certainly different  (we started a discussion of sorts on this elsewhere on the forum so I wont go into it further here).

Regarding tornadoes that form on a storm's NW flank. Tornadoes of all kinds require the presence of an updraft to ingest horizontal vorticity.  In the case of a left-moving classic supercell, yes a tornado would be expected to form under the main updraft or flanking line, which, typically, is on the northern flank in our part of the world. In this case, the thunderstorms were moving northwest. If the tornado developed prior to the onset of precip from the cell, then that is where updraft growth was occurring. As in most cases one of these updrafts probably had a fortuitous encounter with a source of horizontal vorticity producing the tornado. Personally, I doubt this resulted from organised storm scale processes (ie mesocyclonic) given a look at the radar loop, but it's close to the Doppler so the BOM would know what happened and hopefully we'll see a little report come out.

128k radar > http://radar.strikeone.net.au/?fuseaction=loops.main&radar=543&numberofImages=20&dateStart=1154665800&dateFinish=1154676600

[Harley Pearman]

David

Thank you for your reply. This is a learning curve for me and a good answer about tornadoes. I have learnt something. My experience and observations of storms in this region on what I have seen is that the updraft area seems to be on the northern side of the storm (inflow area) and the outflow area on the southern side of the storm, opposite to those in the USA.

I really noted that on the storms of 5 September 2004, 19 september 2004, 3 November 2000, the February 2002 supercell etc and hence thats why I posed that question. I would never expect a tornado to be on the southern side here.

I am not sure whether the storm had supercellur characteristics because I did not have any radars up at the time that it occurred. I am very interested.

I note though that when I was looking after 1 pm the core was still hugging the coast and moving slowly so what I could see, anything substantial would have occurred over the water.

Thank you

Further, I made an error yesterday:- It was the coldest day (11C) since the first Saturday in July 1997 which would have been around 6 July when it rerached 10.4C - another interesting feature of Friday. Harley

[Jimmy Deguara]

David and Harley,

The tornado was also cyclonic which guves it more credibility with regards to dynamics I guess.

Regards,

Jimmy Deguara

[nzstorm]

I think Jon Davies work in the USA on non mesocyclonic cold core tornadoes has a lot of application to this part of the world.  The very steep lapse rates present on the day would have been the main factor in this water spouts/tornadoes development and it would have taken its energy from the relatively warm sea surface temps. As soon as it hit the cold land land it would have started weakening.  Likely to have been some sort of mesoscale boundary associated with it.  I wouldn't rule out a mini supercell.  Given 500mbs temps were -30C, the trop/cb tops can't have been very high.  My thoughts.