erscheinend
appearing
Becoming visible; in the process of emerging.
Der am Horizont erscheinende Vollmond tauchte die Landschaft in ein fahles Licht.
The full moon appearing on the horizon bathed the landscape in a pale light.

appearing / forthcoming
Loading your saved state.
appearing
Becoming visible; in the process of emerging.
Der am Horizont erscheinende Vollmond tauchte die Landschaft in ein fahles Licht.
The full moon appearing on the horizon bathed the landscape in a pale light.

'Erscheinend' (appearing) is the present participle of the verb 'erscheinen' (to appear). It describes an action that is currently taking place or in progress and is used like an adjective.
Die am Himmel erscheinenden Sterne waren wunderschön.
The stars appearing in the sky were beautiful.
This word is used almost exclusively as an adjective before a noun (attributively). Predicative use, such as 'Der Mond ist erscheinend' (The moon is appearing), is uncommon and sounds unnatural.
Der auf der Bühne erscheinende Künstler wurde mit Applaus begrüßt.
The artist appearing on stage was greeted with applause.
The meaning depends on the noun. In connection with visible things (sun, person), it means 'auftauchend' (emerging/appearing). In connection with media (book, article), it means 'veröffentlicht werdend' (being published).
Der plötzlich auf der Straße erscheinende Hund sorgte für eine Vollbremsung.
The dog suddenly appearing in the street caused an emergency stop.
In the context of publications, 'erscheinend' (appearing/forthcoming) is often combined with adverbs of time such as 'bald' (soon), 'demnächst' (soon/shortly), 'neu' (newly), or 'wöchentlich' (weekly).
Die wöchentlich erscheinende Zeitung hat eine hohe Auflage.
The weekly newspaper has a high circulation.
visible
'sichtbar' and 'erscheinend' can both have to do with seeing something. However, 'sichtbar' describes a state: something is visible. 'erscheinend' describes more of a process: something is just becoming visible or appearing. That is why 'erscheinend' often sounds more specific and less everyday. Learners may confuse the words because both are connected with seeing. As a simple guide: 'sichtbar' fits what is already visible; 'erscheinend' fits something that is just appearing.

Am Horizont beobachteten wir die langsam erscheinende Sonne.
On the horizon, we watched the slowly appearing sun.
Bitte klebe das Schild so an die Tür, dass es gut sichtbar ist.
Please stick the sign on the door so that it is clearly visible.