1. Pick Mirana and level up Starstorm
2. Have an enemy unit within 425 range of Mirana, but inside the fog of war
3. Cast Starstorm
4. Check whether the unit was hit or not

Result: The first wave of meteors (which covers the entire 650 radius) does not hit fogged units. But the second wave (the single meteor which hits the closest unit within 425 radius) hits fogged units.

Expected: Just like the primary wave, the secondary single meteor should not be able to hit fogged units.

Here you can see how the main wave never hits fogged units, but the second single-meteor wave does.