Advice (Yellow): an incident has started. There is no immediate danger. Stay up to date in case the situation changes.
Watch and Act (Orange): There is a heightened level of threat. Conditions are changing and you need to start taking action now to protect you and your family.
Emergency Warning (Red): An Emergency Warning is the highest level of warning. You may be in danger and need to take action immediately. Any delay now puts your life at risk. 
Community update (Blue): Specific information and updates for affected communities regarding a particular event or incident.