You could use the addon Srendar, activate the debug options in the addon settings and check which buff ability id is set to your character if the proc occurs.
This ability id, e.g. 34587 or something like this, is qunique then and you can set it up into a whitelist of one of Srendars buffbars to show.
Move that buffar to the left top corner or whereever you want to see it and you will be noticed with the proc buff(buffs if there are more then one procking) each time with your visual style preference (icon, text, ...).
Or try the addon AuraMastery, amybe it can handle it too.