The X-Men films have been going through some significant changes in recent years and as such we don't really know exactly what coming in the future. As an idea, the actress currently playing Storm thinks her character could use her own solo movie. Alexandra Shipp recently said that she'd love to do a movie that focuses on the weather-controlling mutant because it's a film that would specifically appeal to a segment of nerd culture that is often overlooked.
It would be awesome to have a whole movie about Storm... I just want to see it as a nerd myself. I grew up with the cartoons, and it was really amazing to see a superhero who looked like me. I know that through the last X-Men [movie], I got to show this strength to young black girls and young female nerds, and I'd love to expand on that.
Superhero movies are the biggest thing the movies have seen in a long time. While comic books themselves may have been more of a niche product, it seems that everybody loves the movies based on them. The audience enjoying superhero movies is incredibly diverse, yet the characters are less so. Clearly, Alexandra Shipp's comments to Fandango represent what many others probably feel. For her, seeing Storm as a character in the old X-Men animated series was a big deal because there were few characters like her for Shipp to relate to.
Representation is a major issue when it comes to film and as the largest segment of the movie industry from a financial sense, superhero movies are being given close scrutiny when it comes to representing the diversity that exists in the world. Many of the comic book characters that we see on the screen today were created in the 1950s and 60s and, as such, they were created to cater to a white male demographic.
The X-Men, however, were a bit different. Their struggle for acceptance was specifically designed to stand in for the same fight that so many others of different ethnicities and sexualities also had to deal with. As such, their cast was significantly more diverse. The popularity of the X-Men likely led to Storm being one of the most popular black superheroes among all of them in comic history.
Storm is expected to appear in New Mutants which is one of the next major films in the X-Men franchise. As far as standalone movies go, only Deadpool 2 is for sure. Channing Tatum has been trying to get a Gambit movie off the ground and while the project doesn't appear dead, it does seem to be in a continual struggle for survival. A Storm stand alone movie doesn't appear likely at this point, but as things move forward, who knows what the future holds?