What is some foreshadowing in The Grapes of Wrath?

Some examples of foreshadowing in "The Grapes of Wrath" include the description of the dust clouds that precede Tom Joad's return, which symbolize the coming hardships and struggles for the Joad family. Another example is the conversation between Tom and Jim Casy about the changing roles of people in society, which foreshadows the themes of unity and solidarity among the migrant workers.