SnowStorm

SnowStorm is the het ship between Caitlin and Ronnie from the The Flash fandom.

Earth-1
Caitlin and Ronnie meet in StarLabs, where they both work and in January 2012 begin an opposites attract romance, as Caitlin relays it to Barry. Ronnie is a very sweet, kind, outgoing and adventurous person, while Caitlin is equally sweet and kind, but of a more quiet and cautious nature. With unlikely direction from Hartley Rathaway, Cisco discovers that Ronnie is still alive and has merged with Professor Stein as Firestorm (with Professor Stein), their union unstable and subject to a nuclear explosion. Firestorm attempts to sacrifice themselves, but are saved by the Quantum Splicer which separates them and Caitlin and Ronnie finally reunite.

After 14 months of chaotic living, Ronnie asks Caitlin to leave Central City with him and start their life together anew, but Caitlin wants to remain in Central City to help people with Team Flash. After realising that he and Professor Stein are bound permanently by a physiological and psychological connection, Ronnie tells Caitlin that he now understands their lives are altered forever. To research their condition and keep everyone safe from Gen. Eilling, Ronnie and Stein leave Central City to figure out their lives together as Firestorm. They return to help the team capture the Reverse-Flash. Ronnie re-proposes to Caitlin, who accepts and Professor Stein officiates their wedding. They are happily married, but when Firestorm helps Barry close the portal to other dimensions, Ronnie is killed.

Six months after his death, Caitlin works at Mercury Labs as she blames herself for Ronnie's death and couldn't face being in S.T.A.R. Labs day in, day out, being reminded of it. Caitlin tells Barry she thinks that if she'd gone out of town with Ronnie when he asked, he would still be alive. But Ronnie was actually the one who said that they're lives had changed and wanted to leave with Stein so Eilling couldn't harm Caitlin. After Barry and Caitlin talk, she is willing to rejoin Team Flash and start anew.

Earth-2
When Barry and Cisco pay Earth-2 a visit, they come across Caitlin and Ronnie's doppelgängers, who are evil – Killer Frost and Deathstorm. Although evil, the two still display affinity for one another and Killer Frost is livid when Deathstorm is killed.

Fandom
AO3

FORUMS
 * Ronnie & Caitlin

TUMBLR

Trivia

 * "Ronnie used to say we are like fire and ice." - Caitlin. Which is kinda ironic because Ronnie became Firestorm after the particle accelerator exploded and later, Caitlin became Killer Frost. Just like they dopplegängers on Earth-2.