Storm Australian Severe Weather Forum
Severe Weather Discussion => General Weather - all topics not current severe weather. => Topic started by: Jimmy Deguara on 01 August 2006, 02:34:37 AM
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Given it is the most intense storm with the largest insurance payout in Australia's history, this definitely is one of Australia's most significant severe storms. News footage from this event was also beamed around the world.
The question is - where were you on this particular day? Describe what you were doing? Did you get to see the storm as it flickered over the Sydney suburbs? Here is your chance to write your story.
Regards,
Jimmy Deguara
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I was at home (which at the time was the Northen Beaches). I remember Paul Graham called to let me know that there was an intense storm moving up the coast. I went out the back and looked up at a beautiful clear night sky. What caught me eye was the fresh NE winds and low-level strato-cumulus racing in. Hmmm this could be good, I thought to myself. I could also see flashes to the south. Another friend called in to say that his car was trashed (well in reality it was very heavily dented) while on the way to a lecture at UTS.
Pretty soon deep booms of thunder were audible and the storm was clearly dropping these powerful clear air bolts out and to the left of the vault on the northern end. One of these bolts put our power out some time before the storm hit and took me by surprise in fact. As rain turned to small hail (3cm max on out back porch) there was an eerie calm that preceeded a very intense Cg barrage - multiple 'overlapping' flangs at times before sporadic large hail fell. Winds also became very strong, although fearing the worst w/r to what was to come, I was inside with my daughter Kia who was only a little over 4 months old, so I had no idea on wind directions. Luckily that was pretty much it and radar confirmed that the storm has weakened briefly before re-intensifying just to out north.
Also remember speaking on the phone to Michael just after the event that evening.
Now, where were you Jimmy ;D
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Sorry, but no story from me. I was inside and oblivious to the storm until I bought a paper the next morning then I ket out a huge "DOHHHHH"!
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Hi,
Now, where were you Jimmy
Righto smarty panse:)
I guess I was meant to be a storm chaser. That evening I was meant to attended a meeting at the Bushwalking club. I was determined to ensure that I went.
During the late afternoon, I spoke to Paul Graham and I saw some solid towers. I commented to Paul that these towers were unusually large for that time of the year. Paul suggested that the season was basically over though I insisted that this storm was not to be ignored. Something about it's structure attracted my attention. It also had other towers backbuilding. Knowing that they were not in any way heading toward us in the western suburbs, I did not think much more about it after the phone call. At about 7:00pm, I headed for Mt Druitt where the meeting was to be held. It was courageous effort - I had to pass Michael Bath's place which I could have easily stopped by and ignored the meeting. But I was adamant that I would attend to give myself another hobby besides storm chasing. I ignored each flash of lightning.
Later that night, I headed home and noted discussion on the web about the hailstorm. I turned on the news and there were stories unfolding already of the devastation. Of course the footage was of the second storm that did not match the stories of the main event. It was here I realised that I had missed an incredible event. Michael Bath had gone to photograph the lighting from Rooty Hill and I could have done so also. I doubt we would have gone to the city that night.
Yes - you guessed it - no more meetings after that!
Regards,
Jimmy Deguara
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Hey at least I never even saw it, you saw it jimmy and went to a bushwalking meeting! Have you had therapy for that? ;)
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Definitely Jeff, I am now in remission!
Regards,
Jimmy Deguara
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I was just starting to chase at this time and i lived in coogee close to the most intense damage but that morning i was sent to coffs harbour for some boring story and then my flight home that night was cancelled because our aircraft was damaged at sydney airport.......oh the pain .. I then spent about a week covering the damage. Sydney media has forgotten it and does not realiase that things can get so much worse. Andrew meares , another photographer just told me that he was in bondi photgraphing the hundreds of dead seagulls nailed by the hail. My dad lost his roof which was old style slate and then was flooded by the 2nd storm.
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Hi Nick,
I know just how sorry you fealt for those seagulls given your impressive effort to avoid birds on storm chases over the past few years:)
You hit the nail on the head with the flooding by the second storm. This in my opinion seems unprecedented where a second severe storm follows a major supercell such as this and in my opinion contributed to internal damage thence a significant increase in insurance damage bill.
Regards,
Jimmy Deguara
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Hi Nick,
I know just how sorry you fealt for those seagulls given your impressive effort to avoid birds on storm chases over the past few years:)
You hit the nail on the head with the flooding by the second storm. This in my opinion seems unprecedented where a second severe storm follows a major supercell such as this and in my opinion contributed to internal damage thence a significant increase in insurance damage bill.
Regards,
Jimmy Deguara
Hi Jimmy, do you think this was a major factor? The First supercell was HP and had plenty of rain in it so I would have thought the damage would have been done, more or less. I assumed the cost was more likely the result of the demographic that copped it - ie vehicle expenses and the high density and expensive real estate.
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Hi David,
I didn't suggest it was a major factor but if you can provide evidence that it was not at least one of the factors, I'll let it stand. I suggested it was unprecedented where a second storm followed a similar path. I have never to this date observed such an event in Sydney.
And not that the media are as reliable in reporting but I don't recall the media ever covering in such detail internal damage in the March 18th 1990 and 21st January 1991 (except for the high wind component and trees collapsed on houses) - both storms were HP supercells. Which would you rather have David, a few broken roof tiles or a busted ceiling?
One could also argue that the 'tight-arse' attitude of insurance companies in recent years must have also been a factor to counteract demographics including using the tactics of under-insurance. I know this first hand.
Regards,
Jimmy Deguara
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It is worth noting, vehicle claims alone were in excess of 400 million from this storm (which is more than the total bill, CPI adjusted, for previous such disastrous storms eg Western Sydney 1990, Brisbane 1985). Now, in comparison to the 1990 storm - the hailstones were undoubtedly larger in 1999 - evidence for 12cm hailstones as opposed to 8cm (1990). Could that be a reason why the media did not cover such internal damage to the same extent? There were less busted ceilings!
So, while I'd agree that the partial overlap in the track of these two supercells worsened the situation in the coastal suburbs (mostly water damage) and hence would increase insurance payouts I think the sheer size of the hail with the first supercell and also it's track were particularly significant in the 1.7billion figure. If the second supercell did not come through I dont think there would be a massive reduction in this. Also there was further rain after the event and many homes remained unprotected for sometime due to the building boom -- all of this weighs in. 10-12cm hail was the culprit.
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Hi David,
I guess we both are on the same page then.
I am not so sure that the 8cm claim in the 1990 hailstorm is justified. I recall someone who lived in the path of the event in Liverpool and showed the size of the hail to me indicating 9 to 10cm hailstones. of course, I wasn't there and did not measure the stones. Hail >8cm is more than sufficient to bust roof tiles given the threshold suggested by engineers. The density of largest hailsize scatter is important. One could argue that hail to 14cm fell in the Sydney hailstorm:)
Please note that as you suggested David these areas were highe class than most of the areas affected by the 1990 event for instance. Being higher density housing, and the lack of warning contributed to this high insurance payout for vehicles. I would also assume that lower insurance payouts were available to the 1990 affected residents due to affordability of insurance, even knowing rights about what to claim. Very complex issue...
Some useful links in regards to natural disasters:
http://www.disaster.qld.gov.au/disasters/severestorms_history.asp
http://www.bom.gov.au/bmrc/basic/old_events/hawr6/poster_session_1/SCHUSTER_hailstorms.pdf
Regards,
Jimmy Deguara
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Don't forget as well that the rooves damaged in the eastern suburbs were tiled with exspensive glazed clay tiles and not concrete tiles. An interesting fact was that they were pretty much obselete at the time but after the hailstorm monier and other companys began re-production of classic styled clay roof tiles which has since created a resurgence in their use. They are now very popular on up-market home styles!
I can tell you from experience that to repair and replace roof tiles as well as the ceiling gyprock lining and repainting would cost at least about $20,000 per property. Multiply that by how many 000's of propertys that were badly damaged. I don't think it matters as such that rainfall got in after the holes were punched through as you'd have to replace all the above anyway.
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Another interesting fact about the 1990 hailstorm was high glass breakage due to wind driven hail as compared to 1999 where wind wasn't as big a factor and so glass breakage was a lot less. I still remember the news images of dozens of apartment blocks with smashed windows on their western sides in 1990. Think about this, maybe the angle of hail being wind driven would cause less tile damage to tile rooves as more hailstones would deflect off rooves due to the angle of strike. Deadfalling hail over 10cm though with terminal velocities of 60+mph would destroy tiles as we saw in 1999.
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Jes and David,
I have video from an unnamed insurance company showing testing with hailstones hitting tiles based on different hailsizes, etc. I do recall also discussions of hail sizes produced at an angle. You have to be careful in this consideration given the pitch of the roofs. So a hailstone coming at an angle can possibly impact perpendicular to the surface as compared to deflecting hail falling near vertical at an angle to the pitch of the roof.
By the way, I thought it was the southern facing windows that were hammered in 1990 - but that is another discussion. (Given the placement of the core producing hailstones what direction would the hailstones be driven?
Regards,
Jimmy Deguara
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Southern or Western, either way window breakage was a much bigger problem in 1990 as compared to 1999. I don't know fully why but I would bileve that hail that impacts rooves on a flatter angle would tend to glance off more without damage. I have footage from 1999 which shows the hail falling almost vertically which given the size should account for more tile damage you would think than glancing blows.
Physics should proove that glancing hail transfers less energy on impact than directly hitting hail. Also 80% or more of rooves in Australia are built on a 22.5 degree angle which is relatively shallow. They used to build them at a 30 degree angle and i'd suspect that most of the homes damaged in 1999 had a 30 degree pitch.
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I don't disagree Jeff. My point perhaps should have been made clear with more total damage on one or two faces of the roof facing more perpendicular to wind driven hail.
Regards,
Jimmy Deguara
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There is a lot of evidence that the heavy rainfall in the second storm added significantly to the insurance claims. There was a woman working in the organics laboratory at AGAL at the time. She said that it was heatbreaking to see their slate tiles trashed by the first storm. She then described the despair that she and her husband felt when the second storm dumped more rain. Furniture, carpets, books and artwork which they thought that they had saved were water damaged during the second storm. She said that they simply did not have enough buckets and sheets of plastic to cover everything.
Over the next couple of weeks, I received quite a few phone calls from people concerned about possible asbestos contamination in the dust from their ceilings. Almost all of them said that their ceilings had held up until the second storm came through. It was the second storm that caused ceilings to collapse and cause extra damage to furniture and carpets that had not been damaged in the first storm.
I recall one person who was living in a converted factory with an asbestos cement roof. He said that the hailstones went straight through the roof and the ceiling. He also said that even with the hail damage, the second storm addded significantly to the water damage. Definitely that building had to have a thorough clean up of all of the dust before the residents were allowed to return, adding to the insurance bill.
Regards,
Geoff
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Good points Jeff - definitely some violent squalls with the 1990 storm.
Geoff, re second storm, I guess it is all academic. I wonder how significant (ie %) the 2nd cell related costs were in the context of all other damage. Some coastal suburbs received larger hail with the 2nd storm but that was generally golfball sized from memory. As Jeff pointed out, repairs to damaged tiles and roofing would be substantial. There was footage of ceilings with fist sized holes. Perhaps the influx of water was not only from the second storm but 12 cm ice rocks melting in the ceiling:-)
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Hi David,
My thoughts were that the fact that full fledged storm with mostly precipitation and 4cm hailstones just through things over the threshold and contributed to the internal damage. That was my point - though I would be interested in some statistical breakdown.
Regards,
Jimmy Deguara
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Another interesting fact about the 1999 hailstorm was that the major insurance companys teamed up and leased a large industrial lot at weatheril park were most of the written off cars were taken to be auctioned off for parts ( or did the governmant do that? can't remember now). Also they caught a lot of people who had non-severe hail damage who had tried to write their cars off after the storm with sledge hammers! Apparently you can pick the difference between a sledge hammer and a 12 cm hailstone! ;)
I also recall seeing a near new sports car with a dent on it's bonnet so large and deep that the assesor could fit his fist into it and the impact had actually split the steel in the middle of the crater!
Another very expensive item that would have needed replacing is carpet. You could probably add another $10,000 per property just for that alone.
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Sydney Hailstorm 1999
I was watching it from Granville and saw it move along the coastal suburbs. I remember telling Rita at the time before it unleashed onto Sydney that the storm was no ordinary storm. I knew it was a severe storm but I did not know enough about supercells at the time.
I note though that the damage insurance payout was $1,720 million putting it into the Gunness Book of World Records for costly hailstorms (Australian Section) after the event. It still ranks as far as I am aware, the worlds second most costly "hailstorm" after the Dallas - Fort Worth event of 1995 (Not sure what date) but damage from that was around $2 Billion. Amazingly Sydney Australia is up there and holds the Australian records for thunderstorms.
While on the subject of hailstorms and supercells, I pose this:- I am looking at what this season could bring in terms of Supercells for Sydney. I am intrigued that the corridor from "The Oaks to Hornsby" which is a well known supercell path has not fired properly for 4 years. The question is:- Is this ready to fire this year and produce a storm that will go all the way? I worked out, the Average return frequency is 2.66 years and looking at that, one would think that this path which has seen some big supercells would be ready to produce. It produced supercells in 1990, 1991, 1994, 2000, 2001 and last one February 16 2002. (The really big ones). I know there was a small one in late March 2003 but the whole storm collapsed around Seven Hills and did not go all the way. I am talking about something like 3 November 2003. Any discussion on this path as I am paying some attention to it? Thank you.
Harley
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Hi guys,
Relating to the Sydney hailstorm on 14th April 1999, here is a Youtube video of the event with the smaller of the hailstones
http://www.videosurf.com/video/live-footage-huge-hail-smashes-city-4730198
Regards,
Jimmy Deguara