Yes
I don't even know if I want to elaborate[&o]
You are going to have to call louder so it cuts through the rain, depending on how much is coming down. (I'm sure someone will disagree)
Do you know where the turkeys are roosting?
edit: just saw the post...
They have been roosting in pretty much the same location for the past few weeks, changing trees, but not location. They frequent the same field in the morning hours, daily. They have NOT been called to, or distrubed, aside from tractors working the fields that will be corn this year.
and no, rain shouldn't be a major issue. I've killed four turkeys in the rain.
Good Luck, sounds like it will be productive