I think the predictions are made on a computer tracking all the pressure systems in the australia region. If somthing changes such as water temp or intensity of low pressure system than this will drastically change the course of these pressure systems forcing the predictions to be altered.
I fell in to the same problem when i looked at the graph on sunday it said west winds 30-40 knots with 4m of swell, the following day i looked at it and it revealed west winds at 15knots with a 1m swell. The only drastic change which occured in the forecast is the intensity of the wind and waves i believe that this could be due to a pressure system losing some of its intensity or a change in the water temp which would force the system to by-pass the sydney region. Remember the start of this winter we had warm water no westerlies and no snow, i think this was due to warm temps forcing all the pressure systems to miss the nsw region
. As soon as the water cooled of the westerlies came in and it snowed on the mountains.
Hope this hellped you guys understand why the forecast might change so quickly but dont quote me on any of it cos i aint a meteoroligist but if their is any body out there in the now that can either back me up or dis prove my theory i would love to here from them. And birubi willl still go off, trust me!!!
Tim Bailey channnel 10 weather
