In "The Lottery," what details does Jackson use to foreshadow the end of the story in paragraphs 2 and 3?
In the second paragraph, we see that one child has "stuffed his pockets full of stones," and that other children are copying him and doing the same thing. This is a very direct example of foreshadowing: we see characters taking a certain action that doesn't immediately make sense. But it makes sense later when we see that they use the stones to kill the person chosen in the lottery.
Of course, the more interesting bit of foreshadowing in the second paragraph is that the children blindly copy the behavior of Bobby, the first child who starts to gather stones. Why are these kids just doing this behavior because the other kid is doing it? Doesn't that seem like a thoughtless, mindless thing to do? What else would they do if another child did it, or if an adult just told them to do it? This little bit of foreshadowing is more subtle. We might get the impression that the kids' copying behavior speaks to their whole society's willingness to blindly obey what they're told to do, even if it's irrational. And of course at the end of the story, that's exactly what happens.
In the third paragraph, we see how the adults behave: they stand around quietly, talking among themselves, and the women wear "faded" clothes. When we have a story as short as this one, we take every word as a potential bit of foreshadowing, so we might be looking too closely and interpreting things too much--but, by wearing "faded" clothing, these adults may be indicating that they cling too long to things, whether that's clothes that are worn out or traditions that are barbaric and should be abolished.
Although it's excellent advice to pay attention to how weather is described when you're on the lookout for foreshadowing, we don't see any of that here in the second or third paragraph. We're given a description of the warm, sunny weather in the first paragraph, which is not so much a foreshadowing of the story's dark ending as it is a contrast to it.