This event foreshadows the difficulties that the Joad family will face on their journey to California. It suggests that they will encounter many more challenges, including other dust storms, harsh weather conditions, and social and economic injustices. The dust storm also serves as a metaphor for the broader forces of nature and society that are working against the Joads and other migrant workers during the Great Depression. It emphasizes the precariousness of their situation and the importance of resilience and determination in the face of adversity.