Reading the visibility
A pass is only listed when the satellite is sunlit, your sky is dark,
and it is genuinely bright enough to see.
Brightness is apparent magnitude — lower is brighter; the ISS reaches about −3, while a Starlink is typically +3 or fainter. Each pass is checked against how faint the eye can see in that sky, which is why Starlink trains usually only qualify in the middle of the night. The
cloud figure is the forecast sky cover at pass time — even a brilliant pass is hidden under thick cloud.
Excellent — bright & high overhead
Good — easily spotted
Fair — modest, look carefully
Faint — low or twilight-washed