The Canberra forecast ended up getting updated at 9:16am.
Just having a quick look, I see ACCESS-R and EC have rain coming through the ACT (mainly this afternoon). While GFS keeps most of the rain to the north, out of the ACT.
It's a fairly thin line of rain, another 10kms further south and some of those northern suburbs would be under the line of rain now.
But for future reference on BOM's forecasts, the rain chance part in this case means 90% chance of more than 0.2mm, and the amounts stated mean 50% chance of getting 20mm or more and a 25% chance of getting 30mm or more.
On the updated forecast the amounts have been changed to 3 to 10mm, so 50% chance of getting 3mm or more and a 25% chance of getting 10mm or more.http://media.bom.gov.au/social/blog/209/right-as-rain-how-to-interpret-the-daily-rainfall-forecast/