Vantage Pro 2 Rain Gauge blocked

[MBaines]

As we have been having some significant wet weather in the area, I discovered my VP2+ (old style no spikes) rain gauge had become blocked, and while surrounding stations were recording 50-100mm nearby I managed about 2 - the rain gauge cone however was pretty much filled - 18mm from the top.    Anyone know how to approximate a rainfall reading from that - as despite best efforts to unblock the gauge slowly it cleared and the flow was too fast for the system to record properly.  It managed 135+ double tips, but was being held in place by the flow from the cone at times.