Snow on the roof- it's good for something

These areas of melted snow appear to show where insulation was left out of the rafter bays (vaulted ceiling/no attic) and heat is escaping. Scraping away the snow revealed nothing unusual to the eye.

Could it be ceilings lights or fans?

And what were you doing on a Snowy Roof Scraping away snow, I’ve got two plates and 22 screws holding my right leg together from the last time I did that. Be Safem Not Sorry

No recessed light fixtures. I didn’t spend too much time trying to figure it out.