At a short enough distance from the apocalypse, it doesn't much matter whether you're reversing time or predicting the future. Throwing telekinesis in there as well can't hurt. Kids find themselves with superpowers when the right trauma strikes, and there's a perfect storm brewing.

After a sudden storm drops hailstones around the city, people who were hit start developing unusual and often useless powers. They often ironically relate to a person's major struggles and traits. They are triggered by emotions or situations. Thus-empowered individuals start cults, become power brokers, and change the timeline in frankly recklessly dangerous ways- as well as accidently creating imaginary friends, weaponizing milk, and kickstarting a zombie apocalypse.

There is a mysterious conspiracy at the heart of Blackwell Academy; the secrets are kind of bad news

-Reversing time to prevent someone from dying proves to be difficult when the universe wants them dead

-The storm is operating on a timetable; if nothing is done to prevent or divert it, it will happen

-If the storm is not prevented, there will also be storms in other parts of the world

-Powers are first discovered through incidents- varying from minor grievances to major traumas- which tie into a character's personal issues

-Most powers relate to a character's personal hangups or 'character flaws' in some emotional way- anger, regret, lust, social anxiety, being milquetoast, loneliness, purity complex, etc.

-Some people who discover their powers do things like become power brokers who take powers from and give powers to others. Some start cults, others start zombie apocalypses. Sometimes someone gets an OP time travel power, etc.