Hi all,

I recently got a question on an exam simply asking me to enter the direction of the wind in Sydney ___ based on a synoptic chart. The was a high in the area with an isobar line going over Sydney at roughly 330/150. I based the wind direction on the counter clockwise high and adjusted for surface friction to the right. Then entered the 3 digit direction I thought the wind was coming from. From my results I think I got it wrong. Is CASA looking for an exact number ex. 183 or if your answer is in a range it will be correct? I veered the wind by 30 degrees perhaps that close to the water it should have been 10 degrees. Any thoughts or suggestions about this question would be appreciated.

It would depend on whether the high is to the east or west of Sydney. If the high is to the west of Sydney, the wind would be an on-shore wind from roughly the south-east and would be approaching over water. If the high was to the east of Sydney, the wind would be roughly north-west and would be approaching over land. I hope CASA don't expect you to put a plotter on the synoptic chart and I'm sure they wouldn't. There would have to be large margins on the accepted answers surely.

It's a pity that CASA would ask such a silly question (I know they do). If I wanted to know the wind at Sydney I'd listen to the ATIS. In any case the isobars are dynamic not static so they are constantly changing over time.

I don't know of a single case where a practicing pilot in the real world ever consulted the synoptic chart to get the wind direction. The 10°/30° 'rule' is very rough, especially over land because there are so many vastly different land surfaces.