I used the coolant system pressure tester from the local Autozone and was pretty easy to spot then. Fresh snow on the ground and Holy Autolite Batman.
After a very short time at attempting to charge the sytem a 12" diameter puddle was fresh on the ground. Leaking from both HG's and very noticeable.
If not noticeable, a good coating of baby powder aroung the HG areas will be a good marking agent for locating the leaks. And afterwards, she'll smell baby powder fresh.
Wait.. that aint funny...been there.