Skywrite

2nd-Level Transmutation Spell (Artificer, Bard, Druid, Wizard)

Casting Time: Action
Range: Sight
Components: V, S
Duration: Concentration, up to 1 hour

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

Source: Elemental Evil, p. 22