It can be done. The northern beaches graph gets its data from a non BOM weather station.
I set up a weather station at my work that feeds data to a webpage on the work intranet. I think the station cost about $2000. For it to work it needs a computer connected to the weather station and a network connection of some sort.
Here is a screenshot of it. I think Laurie said this weather station's data can be utilised by Seabreeze.