Whatever you say Mark, you're the climate expert.

rpg, McReal and Mark Lawson,

Yasi was defined as cat 5 cyclone. That is misleading.
There's two types of winds in a cyclone. Gusts whose strengths determine the speed and catagory and sustained winds which I think determine the intensity. Assessment of yasi, are missing how the combination of both types of winds determine the destructive strength of cyclones.

The worlds smallest recorded cyclone (Tracey) destroyed Darwin and killed 61, yet one of the biggest (Yasi) wrecked, less damage and indirectly killed one.

Why?

Anecodotal reports tell of gusting winds in Yasi without the sustained winds of cyclones such as Tracey and Larry.
Also the eye of Yasi disintergrated very soon after leaving Tully to the dismay of many.. The Bureau of Meteorology predicted Yasi would be a cyclone until it reached Mt Isa. The sustained winds in a cyclone are predominant around the eye and once they abate and dissappear the system is no longer cyclone but becomes a tropical low with strong winds.

Yasi crossed the coast of a cat 5 cyclone with gusts up to 300klms per hour but it didn't have the worst of tropical cyclonic winds ie Sustained gale force winds of either grades, 69klm per hour or 118 klms per hour, combining with gale force extreme gusts of up to 300 kms per hour.

Hence the lack of Innisfail or Darwin type extensive devastation.

Geoscience Australia models for destructive cyclones. I think they've missed a factor in assessing the destructive impact of yasi. I believe the advice handed to Gillard and Bligh about the destructiveness and the degree of storm surge, by the BOM and Geo Aust, which caused these leaders to state Yasi would be the greastest natural disaster Australia had ever seen, was simply wrong.

There needs be an enquiry into the activities of Geoscience Australia and the BOM since both seem blinded by pro AWG attitudes and since they got it wrong with the Brisbane floods, Cyclone Anthony and their not forecasting of the Toowoomba Range downpour which killed about 20.

I'm an amateur weather watcher.

I predicted to friends, on the morning of the downpour, the Toowoomba Range floods after the Eastcoast low crossed the coast at around Gympie and tracked Southwest towards Toowoomba.

I stated to the ABC, but not broadcast, two days before the Brisbane floods that they would not be as severe or catastrophic as the BOM were predicting.

I also stated on the ABC a week before Yasi arrived that I thought there was a possibility Yasi might abate before it crossed the coast.

How was that?

Isn't that like predicting the winner of the Melbourne cup before the race is run. A weather forecast as i understand it is only good for ten minutes. So I am not sure what a royal commission would establish.
The information we got would have been as up to date as the media would allow. Yasi has still got 90 km winds and it is somewhere in SA.

Keith:
>> The worlds smallest recorded cyclone (Tracey) destroyed Darwin and killed 61, yet one of the biggest (Yasi) wrecked, less damage and indirectly killed one.

Why? <<

Perhaps because Mission Beach and Cardwell are not a cities

Keith, as 'an amateur weather watcher', what do you think might have happened if Yasi crossed at Cairns, or Townsville, instead of the small villages that were wiped out?

""I also stated on the ABC a week before Yasi arrived that I thought there was a possibility Yasi might abate before it crossed the coast.

How was that?""

Posted by keith, Monday, 7 February 2011 4:19:06 PM

"That" was a cyclone that did not abate, or hit a major city. Spoke to a guy from Cairns this morning - he said Yasi hitting Cairns as directly as Tracy hit Darwin would have been far worse for Cairns than Darwin. Wasn't Tully, Cardwell, and Mission beach hit as hard as Innisfail was hit by Larry? Don't forget Dunk Island either - catastrophic, huh?

Good call on Toowoomba rains, though don't understand what you meant about the Brisbane Floods - you mean you predicted they would not go as high as 1974? Because?