Do not listen to silvestris! Hmmm...maybe that should be my signature line? [:D]
Seriously, life is short and you only get so many days of turkey hunting before it's over. Don't waste one because of a little rain. Turkeys are not made of sugar, nor are good hunters.
You can expect them to be more quiet and move a lot more slowly, but they are still spring turkeys. Find a piece of high, open ground if at all possible. I would expect the birds to move out of the timber and loaf in the open. Don't be afraid to call and keep your eyes open for movement.
Now that's downright funny. Good to see you back posting.
If it's raining at flydown, they'll generally stay on the roost longer. They'll also be quieter when they do flydown.
If it starts raining after flydown, they have a tendency to shut up, bunch up and get hinky until they can withdraw to what they feel is a safe place. After that, they remain subdued but sometimes quite huntable.
If it continues to rain, you can usually come out, have a cup of coffee, and change clothes. However, be back out in the open pastures later in the morning or afternoon for an ambush. Turkeys like to go feed on drowned insects and worms, and they'll do so both during a prolonged rain and and after it. My favorite time to be out when rain is in picture either:
1) Just before it rains, say like when a squall line is due in at flydown +1:00. That first hour will be hot.
2) Just as the rain is pulling out. That's when I'm most likely to see turkeys come out to the middle of the pasture.
The hardest part of hunting rain is hearing and being heard. The woods get noisey when it rains. You can't hear the turkeys; they cannot hear you. On the other hand, if you do call and you are heard, you may get a gob coming in. Try some assembly yelping, and then shut up. They like to bunch up when it rains, and if you have a lone turk trying to make contact with a flock of hens, you may hear nothing but a deep cluck when he arrives.