What does the number mean for the enemies???

I'm trying to learn Storm, I legit have like 5 minutes on her I think. I know the blue number is the amount of teammates that are in the radius for her ability, but what about the enemy? What does it do for the enemy? More Storm tips are also welcome, thank you!

https://preview.redd.it/8fk7y5qgeraf1.png?width=1919&format=png&auto=webp&s=4d2f6aab67057119dff2916218f2bc4eb15614d3