The rdwd package provides a collection of all the metafiles on the DWD data server. It is presented as an interactive map below.
When a point is clicked, an infobox should appear. The first line can be copypasted into R to obtain more information on the available files. The map is created with the following code:
library(rdwd) ; data(geoIndex) ; library(leaflet)
leaflet(geoIndex) %>% addTiles() %>%
addCircles(~lon, ~lat, radius=900, stroke=F, color=~col)%>%
addCircleMarkers(~lon, ~lat, popup=~display, stroke=F, color=~col)