What's the difference?
When a HURRICANE WATCH is issued - the possibility of experience hurricane conditions are within 36 hours. This watch should trigger your family's disaster plan, and proactive measures should be initiated especially those actions that require extra time such as securing a boat, leaving a barrier island, etc.
When a HURRICANE WARNING is issued - sustained winds of at least 74 mph are expected within 24 hours. Once this warning has been issued, your family should be in the process of completing proactive actions and deciding the safest location to be during the storm.
Courtesy weather.com