September 30, 1994 to October 3, 1994;

December 31, 1997 to January 7, 1998;

January 12, 2001 to January 17, 2001;

April 30, 2003 to May 8, 2003 [guest appearances]

August 5, 2008 to August 6, 2008;

September 26, 2012 [guest appearances]

Stephen Logan, Jr. was the oldest child of Stephen Logan and Beth Henderson; when Stephen abandoned the family, Stephen Jr., who was nicknamed "Storm" due to his intensity, helped raise his sisters, Brooke, Donna, and Katie, and became very protective of them. When Brooke was almost raped, Storm didn't want Brooke to help her policeman boyfriend, Dave Reed, nail her attackers by using Brooke as bait. Storm also worried about Donna, who had a good-for-nothing boyfriend, Mark Mallory, and Beth, who wanted to pursue her married first love, fashion designer Eric Forrester. Storm briefly dated school chum Alex Simpson, who had had a fling with Eric's son, Ridge Forrester.

Storm was about to have his father declared legally dead when his sisters received an anonymous tip that Stephen was living in Arizona. When Stephen agreed to come home, Storm laid into his dad for his desertion, but eventually saw that Stephen was sincere about making up for the past, especially when Stephen took a job with Spencer Publications in Paris. Storm was happy to see his parents reunited, but never knew that Eric's manipulative wife, Stephanie Forrester, had tracked Stephen down and arranged employment for him to get Beth away from Eric. Later, attorney Storm helped pregnant Forrester Creations assistant Margo Lynley demand child support from her deadbeat, married babydaddy Clarke Garrison; Storm agreed to be the godfather of Margo's infant son, Mark Maclaine.

When a nude photo of publishing magnate Bill Spencer, Sr. was printed in a naughty male magazine, Bill's daughter, an angry Caroline Spencer, hired Storm to find out who its publishers were; Storm shocked Caroline by ascertaining that Bill owned the macho mag himself. After Caroline was diagnosed with terminal leukemia, Storm was surprised to see Caroline's doctor Taylor Hayes, a high school classmate. Storm had been sweet on Taylor and finally got to date her despite her interest in Caroline's widower, Ridge. Storm proposed to Taylor, but when Ridge barged in to talk Taylor out of accepting, Storm punched him.

Before taking a position at a law firm in San Francisco, Storm drew up an ironclad prenuptial agreement for Forrester competitor Sally Spectra, who was marrying the sneaky Clarke, then tried to free Ridge's sister, Felicia Forrester, from a contract she had signed with Spectra. Storm was pleased that Donna wanted to join him in San Fran. Storm did come home for special occasions: Brooke's 1994 and 1998 weddings to Ridge, her wedding to Ridge's brother, Thorne Forrester, in 2001, and a third wedding to Ridge in 2003, which Brooke stopped.

In 2006, Storm was hired by Ridge to represent Taylor, who had been arrested for vehicular manslaughter in the death of Thorne's wife, Darla Einstein; Taylor had hit Darla with her car while drinking. Storm tried to enter a not guilty plea until Taylor sabotaged his case by telling the judge she was responsible for Darla's death. Storm counseled Shane McGrath, the only witness who could testify that Darla's death was an accident. Storm also offered his legal expertise to Donna, who thought she saw Stephanie pushing adversary Jackie Marone over a two-story railing. Storm then worked for Forrester Creations under the ownership of Jackie's son, Nick Marone; Storm helped Nick siphon off Eric's old buyers to keep Eric's new company, Forrester Originals, from succeeding.

Storm represented Nick, who had been arrested for murdering Shane. Storm was sure that Ridge was the murderer and tasked Brooke with getting a confession out of Stephanie; it turned out that Shane had killed himself in front of Ridge, and Stephanie helped frame Nick because Ridge had a police record for once admitting he'd shot Grant Chambers in an attempt to protect the real shooter, Storm's then-preteen nephew Rick Forrester. When Brooke's younger children, Hope Logan and R.J. Forrester, were unintentionally left alone all night and set fire to the living room, Storm represented Brooke against Stephanie and Ridge, who had filed for custody of the kids.

Storm walked Donna down the aisle at her wedding to Thorne, finding out later that Donna was only marrying Thorne as revenge for Stephanie causing Brooke to be raped by Andy Johnson. Then Storm blew up at a newly-divorced Stephen for running out on him, his mother, and his sisters all those years ago; soon after, Stephanie was shot following a fashion show with Stephen as the prime suspect, and Storm leaped to his father's defense. But when Brooke noticed that Storm had a ring identical to the one Stephen always wore, which was seen in a police photograph, Storm admitted that he shot Stephanie for causing Brooke's rape and framed their absentee father for it. Storm couldn't believe it when Stephen wanted to confess to protect him; father and son went free because Stephanie promised Donna she'd ask the court for leniency as long as Donna left her new boyfriend, Eric.

Storm left for Europe with Stephen to find Beth and get help, but Storm came back to Los Angeles, entering therapy locally. Storm realized he was going to jail when Donna confessed she had tried to fool Stephanie into thinking she'd broken up with Eric; Storm was ready to turn himself in when Katie begged Stephanie for compassion. After Stephanie let Storm off the hook, Storm represented Nick in a custody case against Taylor, who had fallen off the wagon after learning that her baby Jack Marone, born from a donated egg, was Brooke's biological child.

The love-starved Storm was thrilled when Brooke set him up on a date with Genoa City transplant Ashley Abbott, even though Storm knew that Brooke wanted to keep Ashley from reuniting with Ashley's ex-fiancé, Ridge. Storm and Ridge came to blows when Ridge deemed Storm dangerous; after Ridge ruined Storm's chances with Ashley by telling her Storm shot Stephanie, Storm accosted Ashley, explaining his motivations and frightening Ashley by showing her the gun he used in Stephanie's shooting. When Katie burst in thinking Storm was threatening Ashley, Storm accidentally shot Katie in the heart struggling over the gun, not realizing it was loaded.

With Katie about to die because there was no available heart donor, and facing a long jail term for two shootings, Storm left Katie a note, then shot himself in the head to donate his own heart to Katie; Storm died clutching Katie's picture in his hand. Katie has gone on living with Storm's heart beating inside her; Storm appeared to Katie in visions twice in 2008, imploring her to live after his sacrifice and then seemingly inviting her to join him on the other side when she got pregnant by Nick, the husband of her niece, Bridget Forrester. Katie last had a vision of Storm in 2012, when she nearly died in childbirth. Storm has been mentioned several times by his sisters in the years following his death.

In 2019, an online DNA testing site revealed there was a 52% chance Storm was the father of Florence Fulton, the result of a brief fling in Las Vegas with casino worker Shauna Fulton. Storm was never aware he had a daughter in his lifetime.