The type of alert used depends on the severity and timing of the event:
Warning
Urgent message that severe weather is either occurring or will occur
Updated regularly so that you can stay informed and take appropriate action
Watch
Alerts you about weather conditions where there is potential for a significant storm or severe weather to occur
A Watch may upgrade to a Warning as certainty increases about the path and strength of a storm system
Advisory
Issued for specific weather events (like blowing snow, fog, freezing drizzle and frost) that are less severe, but could still significantly affect Canadians
Special Weather Statement
The least urgent type of alert
Issued to let you know that conditions are unusual and could cause concern