In "The Storm," Calixta has an affair with another man while her husband and son are waiting out a storm at a local store. In this story, the affair is not presented as something evil or even something that would make Calixta feel guilty. Rather, the affair is presented as a celebration of women's sexuality. It is a celebration of the freedom to express female sexuality by Chopin herself. So, as it is an expression of passion, note how the storm is analogous to Chopin's expression of female sexuality as well as Calixta's passion within the context of the story.
. . . the storm burst. It shook the wooden store and seemed to be ripping the furrows in the distant field. Bibi laid his little hand on his father's knee and was not afraid.
The clouds roll in with their "sinister intention from the west, accompanied by a sullen, threatening roar." The oncoming storm foreshadows something apparently "sinister." The storm shakes the store while Bibi and his father wait. The release of the storm parallels the release of passion between Calixta and Alcee.
The storm seems threatening and violent when it begins. With the analogous affair, Calixta's act could threaten her marriage. However, in the end her marriage stays intact. Chopin shows that just as men have moments of passion and lust, so do women. If it is healthy for men to have urges, it is healthy for women as well. Likewise, the storm is nature's way of releasing energy. It was simply a temporary surge of energy (storm and the affair). The storm was foreseen as threatening but was just a passing storm. The affair has the potential to threaten the marriage, but it was just a passing moment of passion. Thus, the story ends with "So the storm passed and every one was happy."
As far as the plot is concerned, the introduction of the treacherous storm in Part I explains why Bobinot and Bibi are marooned at Friedheimer's store for the afternoon. This stay keeps them away from Calixta, whom they assume is eagerly awaiting them at home.
While they wait out the storm, Calixta engages in a passionate afternoon tryst with Alcee Laballiere, who seeks shelter from the storm in Calixta's home.
While readers would expect an extramarital affair to tear a family apart, both Calixta and Alcee's families are content, and even strengthened, after the storm. The last line of the story reads, "...the storm passed and everyone was happy."
Also introduced in Part I is Bobinot's naivety concerning the thoughts and feelings of his wife. As he and Bibi marvel at the storm, Bobinot says to Bibi, "Mama'll be 'fraid, yes." However, we discover in Part II that Calixta barely notices the storm nor the absence of her husband and son. Bobinot does not know his wife's heart, which likely explains Calixta's desire to seek fulfillment in someone else, albeit temporarily.
Chopin's concise, evocative technique is evident in Part 1 of "The Storm." With a few strokes of the pen, Chopin establishes the character profile and relationships of the key characters: Bobint is a compliant, if somewhat dim, husband and affectionate father; Bibi is remarkably observant, wise for his years; neither character is truly "afraid" for Calixta, whom they both clearly love. The impending storm is a classic example of foreshadowing; it symbolizes the turbulence of Calixta's repressed desire and the threat to her marriage; it also serves efficient double duty as the element of the plot that will delay father and son, creating the opportunity for her affair. Yet even in the story's opening, we are assured that this is a passing storm, literally and figuratively; neither father nor son is substantially threatened by it. Bobint buys the can of shrimps his wife prefers and "stolidly" waits out the storm, confident of his dinner, and ultimately, his wife.
The focus of the question is specific to Part I only; thus, it is imperative to look closely at the small details Chopin offers. "sombre clouds...with sinister intention..." suggesting something ominous about to take place, but the "rolling" foreshadows the speed of the affair that will take place in Section II. The seemingly insignificant conversation between father and son sets the reader up to know that Calixta is a married woman, and a mother. If there are degrees of seriousness in one that has an affair, a married woman's participation might be looked upon more harshly than perhaps a single/unmarried woman. Furthermore, she is all alone at home with no help; thus, the set up for a perfect storm in the form of a tumultuous affair.
The reader is also provided a possible glimpse as to the constitution of the husband as he " purchased a can of shrimp of which Calixta was very fond." The reader should ponder the husband's action, does he suddenly make this decision due to a guilty conscience. The conclusion of the story will provide evidence to his behavior, but not in his case the guilt of adultery, but that of leaving his wife alone in a dangerous storm; but also, and perhaps amusing, the guilt of allowing his young son's clothes to become so filthy: Bobinot even imagines the conversation that takes place; thus, reinforcing what the reader is first exposed to in Section I, the rather weak, perhaps hen-pecked husband that is too oblivious to recognize the real fear Calixta may have experienced while her family was away, that is, the fear of a family retuning home so soon.