Forecast rainfall by date and model run (GFS). The current 10 day forecast total is 35mm.
Top graph has the model runs (every 12hrs) along the x-axis and each day is represented by it’s own line. Each line represents all the different forecasts made for that day across all of the preceding model runs. A line that is consistently high or low means that day is likely to be wet or dry, lines where the is a high degree of variability means that the model isn’t sure what will eventuate, although data to the right of the graph is more likely to be more accurate than data on the left as forecasts on the right are closer to the date on which the rain is expected to occur.
The second graph is the reverse of the first, with dates along the x-axis and the model runs represented by the lines. This is probably the easier to read, as you can see all the different forecasts made for a given day. Again data from more recent model runs is likely to be more accurate than data from older model runs.
The Weather Project 