Altocumulus clouds are being illuminated by the setting ... and temperatures are back above average in the middle and upper 40’s Skies will slowly clear out for Thursday evening, just in time ...

They discovered that these peculiar shapes form when planes fly through "altocumulus ... patchy clouds form at mid-level ...

Because of their rarity and unusual appearance, fallstreak holes, or punch hole clouds, are often attributed to UFOs because they form as large circular gaps in cirrocumulus or altocumulus clouds.