Skywrite
Source: Xanathar's Guide to Everything, DND 5e Wiki
2nd-level transmutation (ritual)
Casting Time: 1 action
Range: Sight
Components: V, S
Duration: Concentration, up to 1 day
You cause up to ten words to form in a part of the sky you can see. The words appear to be made of cloud and remain in place for the spell’s duration. The words dissipate when the spell ends. A strong wind can disperse the clouds and end the spell early.
Spell Lists: Artificer, Bard, Druid, Wizard