“--we know from Cairns luck improves with preparation.”

Cairns’ luck had more to do with the fact that cyclone Yasi crossed the coast 120 kilometres south of the city rather than ten kilometers north of it.

The community risk for Cairns remains much the same as it was more than a decade ago when the Multi-hazard Risk Assessment for Cairns, provided by what is now Geoscience Australia, was published.

What silliness! Cairns had a little bit of strong wind. New Orleans had a hurricane. As for Tully, Cardwell, Mission Beach, Dunk Island, Ingham and, to a much lesser extent, Townsville ... well, they didn't fare so well as the Cairns region.

I tend to agree with the 2 comments so far - this is rather a foolish article. The cyclone passed to the South of Cairns. To my enormous relief it passed just south of Innisfail where I live. Wind strengths in Cairns were much less than in Townsville. It was a very large cyclone, but I suspect will be found on analysis not a very strong one. My guess having had a good look round at tree damage and in particular whether the poor things had any twigs left (they nearly all do)I suspect that it will turn out to have been a 4 at most. If I am wrong, well so be it.

Neither Tracy or katrina were much of a learning thing for coonstruction in the NE tropics. there was an upgrade of rules after Althea in Townsville in the Early seventies. Further changes occurred, especially for ridge top buildings after Winifred (Innisfail)in 1986, and of course there was the powerful though small Larry. Poor Innisfail again.
Katrina is irrelevant. if you build a city below sea level...well, what do you expect? Construction methods in Darwin prior to Tracy seem to have been low, lacking adequate bracing and roof strength.

What we do learn each time is the importance of precautionary organisation for the post cyclone period. As one who has been through more than enough cyclones I feel justified in saying that the organisation for the peoples relief has been superb. it also seems possible that the post Larry 'kill all trees' policy has been stopped. Certainly after Larry there was planning through the Terrain NRM to improve that aspect of recovery.
Perhaps the author would do well to reconsider his opinions especially his views on the significance of Katrina and Tracy. His emphasis on organisation before the event was spot on though.

In the Cardwell area it looks like there has been a nuclear agent-orange attack.

Townsville got flogged by the equivilant of a cat 3, some would say a weak cat4.

I would be in agreement with some of the above comments.

A severe cyclone will take the leaves off native trees, and that did not happen on a large scale. All areas were spared a major tidal surge, as the cyclone did not cross the coast at high tide.

Improved building codes certainly have helped, and there was some good organisation that also reduced risk.

Of great concern is Mackay that does not have one designated cyclone refuge center for a population of 120,000, when there are 3 major shopping centers, plus innumerable solidly built warehouses that could be used as cyclone refuge centres.

Of concern is also the southeast corner of QLD. It is only a matter of time before a severe cyclone goes over the top of Brisbane, and the state of QLD is now so centralised, it will bring the whole state to a standstill.

Also of concern is the state of Australia’s navy. It is so lacking in engineers and skilled personnel, most of our naval ships are non-operational and could not be used to give aid to the north of QLD if they were required. Luckily they were not required

http://www.theaustralian.com.au/national-affairs/defence/cancerous-morale-risks-our-navy-fleet/story-e6frg8yo-1226008439486

vanna, I don't know where you and others are getting your information from. Let me assure you the tv pic do not do justice to the destruction caused by Yasi.

All the native trees leaves were stripped in Cardwell/Kennedy area and most of Tully. The place was stripped, big trees smashed and twisted. In my yard 3 mature coconut trees were twisted from thier roots at the base of the trunk. I have not been to the beaches near Tully but I have heard they were very hard hit.

The leaves of trees were minced. My home had minced leaves throughout the whole place - they came in through any possible gap in louvres etc. Thankfully, due to the rain and sunshine most of the trees are getting small leaves emerging (unlike after Larry when it rained so much nothing grew for ages).

A person living 10 km inland from Cardwell said that the rain during the cyclone was salt-water.

I find it astounding to read the opinions of people who are obviously not from the area where Yasi hit, or who have not visited it

Aka,
When leaves are stripped from native trees, and whole hillsides are brown afterwards, then that is a major cyclone.

However it did not occur much in Townsville or Cairns, and only occurred in less populated regions.

Many trees that come down in towns during cyclones are hand planted, and are often pot-bound when planted, and the root system does not form a proper tap root.

I have been through a cat 3-4 while living in a beachfront house, and seaweed was stuck to the walls and windows afterwards, and after cyclone Ada, periwinkles were found in swimming pools at Airlie Beach.

I tend to think that Yasi was very broad, but the destructive winds were not that extensive.

If a major cyclone does go over more populated areas, then the destruction to property and possible loss of life will be greater.

vanna, you state that "When leaves are stripped from native trees, and whole hillsides are brown afterwards, then that is a major cyclone."
This is exactly what the Cardwell/Kennedy/Tully area is like.

You are welcome to hold your opinion, based on Cairns and Townsville and Mackay, but you are plain wrong.

Based on your definintion and description of a cat3-4 Yasi was a monster. Just because you were not here to witness the devestation does not make it any less real. I find it odd why anyone would want to try to argue that Yasi was not a super cyclone, and that it was just lucky it did not hit in a major city.

Oops I meant to say:

I find it odd why anyone would want to try to argue that Yasi was not a super cyclone.

It was just lucky it did not hit in a major city.

aka,

The eye of Yasi was 30 klms across. If a cyclone cat 5 that big crossed the Cassowary Region then everything, not just flora, would have been flattened ... like Darwin with the Cat 4 Tracey. Tracey's eye was 7klms across.

While Darwin's relatively lax building code resulted in 9000 homes being totally destroyed. Yasi destroyed totally only 105 homes, according to 'Tropical Disaster' Anna.

Qld building codes only require homes to be built to survive cat 4 cyclone conditions.

So why weren't Ingham and Inisfail destroyed? It simply wasn't a Cat 5 Cyclone because if it had been then cyclone cat 5 winds would have battered both those towns and both Cairns and Townsville would have seen huge devestation from at least cat 4 winds.

Another pointer that it wasn't a cat 5 was that the eye dissapated quite unexpectedly quickly after leaving the Cassowary Coast region. No cyclone damage from severe destructive winds was experienced further inland ... they suffered only torrential rain.

Yeah I'd argue it wasn't a cat 5 cyclone and if you think it was you will be in terrible danger if you think you can clean up, 'bunker down' and ride out the next Cat 5 Cyclone that comes to town.

Aka,
It appears that Yasi has been rated cat 4-5.

For example,

Yasi maintained Category 3 intensity for the next 24 hours before being upgraded to a Category 4 at 7pm on 1st February. During this time, Yasi started to take a more west-southwestward movement and began to accelerate towards the tropical Queensland coast.

Yasi showed signs of further intensification and at 4am on 2nd February and was upgraded to a marginal Category 5 system.

At the time of writing there are no verified observations of the maximum wind gusts near the cyclone centre. However a barograph at the Tully Sugar Mill recorded a minimum pressure of 929 hPa as the eye passed over suggesting wind gusts of about 285 km/h were possible.

http://www.bom.gov.au/cyclone/history/yasi.shtml

As I have mentioned in a previous post, it was lucky that the cyclone did not cross the coast in a more populated area, it was lucky that the storm surge was not larger, it was lucky that Yasi did not cross over Mackay because of a lack of cyclone refuge centers in that town, and I personally think that extensive damage would occur to Brisbane if a cyclone of only cat 3 ever went over the top of it.

The Australian navy is also in such an inglorious state at present it could not be relied upon to offer any type of assistance in the case of a major emergency.

Our 3 biggest navy ships were all non-operational at the time of Yasi, and one has to question why we bother with a navy.

vanna,

let's get some facts straight.

If wind gusts at Tully Mill were assessed to be 285klms/hr then sustained winds (1 Min) according to the methods used in assessing both sustained winds and wind gusts in Cyclone Tracey, there would have necessarily been sustained winds(1 Min) of 240Klms/hr within approximately 80klm the edges of the eye. ie sustained winds (1 min) would have been greater than the maximum gusts of 181klm/hr recorded at South Johnstone during Larry, and they would have smashed both Innisfail and Ingham ... worse than Larry in Innisfail.

Fact.

For confirmation have a read of the Official BOM report on Tracey from around pages 40-45, from memory.

I get the feeling that you all think that if another Cat 5 cyclone passes through Mission Beach and the Cassowary region the destruction will be pretty much as occurred with Yasi.

If that's the case and it is indeed a feeling held in the community from Cairns to Townsville, then a terrible terrible error is being made and you are abetting setting up the community for a catastrophe.

keith,
From general experience with more cyclones than I care or want to remember, I tend to think strong wind gusts during a cyclone do the most damage, as well as storm surges and flooding from rain.

If a cyclone is category 3 and above, it is dangerous, and strong buildings are necessary, with expected loss of electricity supply to some or most areas in the cyclone path.

Category 4 is worse, and category 5 basically requires mass evacuation.

What happens afterwards is perhaps more important, as power has to be restored, roads cleared, fuel made available, bridges repaired and food delivered.

The author maintains that good organization occurred. I think that there was good organization for a cyclone that hit a small population, but if Yasi had hit a more populated area, the situation would have been very different, and the armed forces would have been required.

If the roads are cut, the army cannot get through. If the air port is out, the air force cannot land planes until they can get the air port operational.

The navy could get ships into the area, but most of our navy is currently non-operational and unreliable, and would be of little use to supply aid to a large population.

Vanna,

You are right to say that it is the severe wind gusts that do the most damage during cyclones.

Larry's cat 4 severe gusts were recorded at 181klm/hr and they destroyed much.

Tracey's severe gusts were recorded at 217klm/hr and they destroyed totally.

Now given how wind speeds are calculated in cyclones [See Tracey Official report for info on how that is done (pages 45 approx)] Yasi's sustained winds (1 min) should have been at 240klm/hr for over 80klms from the edge of the eye, and given your experience can you please explain to me how anything was left standing from Ingham to Innisfail if Yasi was indeed a cat 5 cyclone?

Please note that sustained winds in a cyclone are multiplied by a factor of 1.2 to ascertain the stronger wind gusts. Sustained winds are gusts that last for one minute and longer...which means all the winds within 80 klm of the eye in Yasi would have been stronger than anything you've ever experienced in any cat 4 or lesser cyclone.

Surges are caused by the action of wind, wave and tide. The stronger the winds the bigger the surge.

Now please tell me why Cat 5 requires mass evacuation?

As far as organisation of the rescue operations, I think you're kidding yourself. I was talking to one of our SES volunteers yesterday, & he was totally scathing of the organisation.

He was one of 80 very experienced SES volunteers from SEQ who flew into Cairns to help out. First they were horrified to find the transport organised for them was a fleet of hired Toyota Camrys, not quite ideal for flooded, littered & damaged roads.

Despite this, it was not the army with their high clearance 6X6 trucks that were first into a number of the isolated coastal communities, it was "the charge of the Camrys" that led the way. In some instances the media were in the lead, but at least they had 4WDs to drive.

Fortunately, some of them had a fair idea of what to expect, as they got no useful support locally. What they took with then was it, even down to fuel for the chain saws.

Organisation, what's that? Perhaps that what left Horseshoe Bay, on Magnetic Island, off Townsville, without help for so long.

Yes that's right, Townsville, a long way from the centre.

This cyclone was like a number I have experienced. A moderate, very large system, with pockets of very severe storms embedded within it. Those who got those pockets probably had true Cat 5 strength. This is where the false claims of Cat 5 are coming from. Of course the pollies jumping on the biggest claim they can find to build their drama. This makes it hard for the BOM to then tell the truth.

Keith,
"Now please tell me why Cat 5 requires mass evacuation?"

In most of our towns, people cannot live for very long without electricity.

They will have no drinking water, lighting, cooking facilities, food refrigeration facilities or sewagage disposal.

A cat 4 cyclone can mean large areas will be without power for many days or a number of weeks (and I was on the edge of a cat 3-4 last year and some areas were without power for 2 weeks afterwards)

A cat 5 cyclone going over a town will not only wreck many buildings, it is likely to wreck most of the electricity supply lines also making it impossible for most people to live in the town afterwards.

Hasbeen,
It is interesting that the SES were called into Townsville when Townsville has a large army base.

The current situation with the navy is that it is unreliable in an emergency, and perhaps the army is just as unreliable also.

WTF?

Seems like someone has cyclone envoy – my cyclone is bigger than your cyclone.

Grow up you poor sad creatures.

'A cat 5 cyclone going over a town will not only wreck many buildings, it is likely to wreck most of the electricity supply lines also making it impossible for most people to live in the town afterwards.'

And that didn't happen in most of the Cassowary coast nor in Ingham, Townsville, Innisfail nor Cairns. Only 105 buildings were destroyed. Compared to 9000 in Tracey. And there was no great exodus because the region was unliveable whereas 2/3 of the pop of Darwin was evacuated.

So where was the cat 5 cyclone?