Usage Notes For The Australian Analysis and Forecast Soundings
Selecting the latest GFS forecast dataset
The latest complete forecast dataset or "run" is automatically selected for you. However, because of the way the system updates the data files for the runs, data for the next run (when it becomes available) will be accessible in set increments as the data files are downloaded. For example the latest complete run may be the 00z run, but as the 06z run becomes available it'll be labelled "First 12 Hours Avail", then 10-15 minutes later "First 36 Hours Avail" etc. This continues until the run has been completely downloaded, at which point it'll be labelled "All Hours Avail". The update increments are 12 hours, 36 hours, 72 hours, 120 hours and finally 180 hours for the full run. The benefit of this is essentially having each run, in part, available up to an hour before it would otherwise be available. For example having the first 12 hours of forecast data from the overnight 18z run available at not long after 7:30am of a morning, as opposed to 8:30am from many internet sources, can be a priceless time advantage for storm chasers wanting to browse the latest model forecast before heading off to their target area for the day.
Selecting a lattitude and longitude
The map provided covers the area for which forecast data is available - that is, the area bound by 110E to 160E and -10S to -45S. The white dividing line between the map and the colour bar at the bottom of the map marks the southern most extent of the forecast data.
Lattitude and longtitude figures obtained by clicking on the map are as accurate as they can possibly be - within a decimal point of a degree of lattitude and longitude.