Ice on the roads develops as a result of cold and wet conditions.
These warnings apply primarily to the road conditions, whilst differentiating between the following hazards:
- Slippery conditions due to packed snow: Snow that has frozen solid on the roads (up to 4 cm thick).
- Black ice: Wet roads which subsequently freeze over as a result of clear skies at night.
- Icy roads: Cold or cooled precipitation (freezing rain/drizzle) that falls onto a road surface with a temperature below 0 degrees, thus freezing solid instantly.
Please note: warnings for slippery conditions due to ice or snow are not issued foraltitudes above 800 m.