I havent killed as many Toms as your gf's Dad has but I've killed a few in my day and not one hunt was the same as the others. Most of the time when I'm hunting and its rainy, windy and cold I hardly hear a peep out of any turkeys. I usually will just quietly spot and stalk becasue I feel its easier becasue the warm weather doesnt have them all wound up. I have found turkeys to be like teenage boys...If its beautiful warm weather they are all over the place wanting to check the next girl that will give them a chance out but if its rainy and cold they tend to hangout in a certain area and keep to themselves... I have had a few toms to respond to calling in these weather conditions but they were eager 2 year olds...I would prolly just wait where theyare roosting and try to catch them coming back to roost.
"Go afield with a good attitude, with respect for the wildlife you hunt and for the forests and fields in which you walk. Immerse yourslef in the outdoor experience. It will cleanse your soul and make you a better person." -Fred Bear