I also wanted the DWD Warnings in openhab, but I didn’t really like the solution with a cron script.
So I decided to build my own binding. It’s currently working on my local openhab installation. I’m thinking about filling a pull request (would be my first), but before I would like to have some comments.
The source code is here: https://github.com/limdul79/openhab2-addons/tree/dwd/addons/binding/org.openhab.binding.dwdunwetter and jars (for 2.4.0 and 2.5.0-SNAPSHORT) can be found here: https://drive.google.com/drive/folders/1vUTIWki45CDxVHP2aepX1aLaIuTf9Aut?usp=sharing