[4] MetService issues Severe Weather Outlooks, Watches and Warnings under a Code of Practice that enables others to distribute this information in the national interest.
Red level is for weather that can mean big danger, serious damage, and major disturbances.
This can refer to many types of weather related events such as wind, flooding, snow, forest fires, etc.
Until 2021 the SMHI its own warning level terminology, Class 1, 2 and 3, fairly much corresponding to Yellow, Amber and Red.
The NWS defines a watch as "the risk of hazardous weather or hydrologic event [increasing] significantly, but its occurrence, location, and/or timing is still uncertain" and a warning as "hazardous weather or hydrologic event [that] is occurring, is imminent, or has a very high probability of occurring".