One thing that has intrigued me is repeated claims in news.com.au and its subsidiaries that the Victorian floods in the last 4-5 days are due to Yasi. They have cited BOM in those claims ....

I thought they were more due to a cold front coming from the south west hitting the High over NSW, with only a possibility of an effect from the remnants of Yasi (or Yasi and Anthony) near Mildura in recent day or so?

keith, I'm in the USA, it was reported here that the cyclone had lost intensity gained intensity and everything in between.

If BOM now say it was cat 5, I stand corrected.

This is the problem with the alarmists all piling on, the exaggeration is difficult to separate from fact

Bonmot
data makes it appear your claim may support my theory of Yasi being less destructive than expected. It certainly wasn’t Australia greatest natural disaster, as Gillard and Bligh claimed.
The Cassowary Coast region is where the centre of Yasi crossed.
It includes the towns of Innisfail, Flyingfish Point, Mourilyan, Al Arish, Kurrimine, Bingal Bay, Mission Beach, Tully, Tully Heads and Cardwell, as well as the islands of Dunk, Gould and Hinchinbrook .
From Cardwell to Innisfail is about 50 klms.
Pop was 31,000 in 2006.
Pop of Darwin was 40,000 in 1974.
Yasi’s eye was 35 klms across. Innisfail and Cardwell should have been hit by cat 5 gales and sustained winds and destroyed. The BOM, when it predicted Yasi would go ashore at Innisfail said
‘VERY DESTRUCTIVE winds with gusts above 280klm/hr between Port Douglas and Cardwell’
They also stated Yasi’s
‘IMPACT IS LIKELY T BE MORE LIFE THREATENING THAN ANY EXPERIENCED DURING RECENT GENERATIONS’. (Their capitals)
Since the eye actually passed 50 kms south of Innisfail and also closer to Ingham, those forecasts now seem inaccurate.
150 dwellings were utterly destroyed in the Cassowary Coast region. (ABC News Monday 7 Feb 2011). Photos show many buildings in the worst hit areas, including Dunk, remain mostly intact and not utterly destroyed. There‘s no significant damage in Innisfail or Ingham.
Gale force winds upto 240klm/hr extended only 48 klms across Darwin. Darwin had 70% of its buildings utterly destroyed, which included 80% or 9,000 homes. Tracey was cat 4.
If it’s possible please I’d like to know type of winds your friend experienced?
Friends in Townsville confirm gusty nature of Yasi, as did an interviewee, on ABC radio from Mission Beach as Yasi’s eye passed over.
Had Cairns or Townsville been hit by the eye I suspect similar damage as has occurred across the whole of the Cassowary Region.
McReal,
the two previous 2011 cyclones (Tasha and Anthony)slowed dramatically and abated and crossed the coast as cat 1

cont
I suspect rain in Qld has not only caused an ocean of water to flow to Lake Eyre and the Murray but also an ocean to flow into the waters between the coast and the reef. Sunshine has been insufficient to heat that water to the 26.5 degree C. or the temp at which cyclones originate and sustain. I suspect as the cyclones crossed this, cooled and lost velocity and wind speed (Sustained wind speeds).

The 74 floods were different in four major factors.
Firstly, in 1974 there were Spring tides. This time there were only King Tides.
Secondly in 1974 torrential rain fell across the region through the floods. This had two effects, the run off below where Wivenhoe is now and Brisbane added to the flooding river and the Brisbane creeks, streams and flood flows suffered localized flooding and couldn’t run off. They backed up causing further widespread flooding.
Thirdly the sun shone for two days prior to the flood 2011 and no significant rain fell in Brisbane or it’s river catchment for that period.
Fourthly the Bremer River a major tributary, never reached the flood heights of 1974. It started falling before Brisbane flooded.
Other factors contributed, among them was the rate of rainfall that fell across Lockyer Creek catchment, another Tributary, and the velocity of its dramatic and tragic traverse across and departure from the Lockyer Valley and its subsequent flow down the Brisbane river. 400mm fell in 4 hours onToowoomba on the Monday. (300mm fell in Innisfail during Larry).

Flood height at the City was one metre less than the 1974, 5.6 metres .
rpg
Technically it was a cat 5 as it approached Willis Island. (500 kms from the coast.) Sometime after that it lost its sustained winds. Its gusting winds were always at cat 5 level… but I have no idea how many gusts were recorded at that level. I wonder how many gusts at 300 klms it takes to make it a cat 5?
I’m working on an olo article.

You obviously have done some homework Keith, good stuff.
The building codes of 40 years ago didn't help either and because of Tracey, the codes were improved to better cater for cyclones.

<Flood height at the City was one metre less than the 1974, 5.6 metres . >

Yes, but the Wivenhoe Dam did not exist in 1974. What would the height of the flood have been without it? BTW, the flood height in 1893 was about 9 metres.

So what did the CSIRO have to say?

http://www.csiro.au/science/adapt-extreme-weather.html

"Australia is likely to become warmer over the coming decades, with a reduction in average annual rainfall in the south-east, and uncertain changes in average annual rainfall in the north.

Climate variability from year to year and within years will be superimposed on these trends in average conditions. For example, a warming trend will include some cool years and many hot years, and a drying trend will include some very wet years and many dry years.

In this highly variable climate, future severe storms and extreme rainfall events are likely to be more intense resulting in more severe flooding."

The only absurdity is the ridiculous distortion of the article.