That experience and your comments highlight to me a fundamental problem with modern Australian aviation forecasts - and that problem is the over reliance on computer modelling. On the day in question it was obvious (for at least an hour beforehand) to anybody that bothered to look out the window or at a weather radar that SYD was going to be affected by TS. ie the human assesment was that the probabilty of TS was close to 100%. Yet nothing on any forecast. I suspect that the BOM was blindly issuing the computer model generated forecasts and the models had the prob at less than 30%. But the models were simply wrong and there was no human input into the accuracy of the forecast, ie using the Mark I eyeball to have a look out the window. I also suspect that ATC at SYD rang up the BOM after the airfield was closed and asked why the TTFs didn't have TS on them and then there was a mad scramble to catch up with reality.
Not too long ago TTFs were issued by real forecasters that used a blend of modelling and local knowledge and experience. That's what is missing these days - the human input. And that's why QF are paying for BOM forecasters to keep an eye on things and if the computer modelled forecasts aren't up to scratch it imposes it's own operational requirements in the form of OPRISK notices to it's crews.
Last edited by Bleve; 17th Jan 2007 at 04:47.