Hurricane Watch Vs. Warning: What the Terms Mean, and What Is Storm Surge?

Hurricane season in both the Atlantic and Pacific basins is in full swing and those who are on guard for the possible storms heading their way should be aware of the terms used in a hurricane situation.

Some of the terms used can mean the same thing, like how hurricanes and typhoons are both names for tropical cyclones. But there's one distinction those bracing for a storm should be highly aware of—the difference between a hurricane watch and a hurricane warning.

A hurricane warning is more serious than a watch because it is issued when hurricane conditions are actually expected in an area. It means that there are sustained wind speeds of 74 miles per hour or more accompanying a cyclone expected in an area where the warning was issued, according to the National Hurricane Center. Warnings are issued 36 hours before the winds are expected to reach an area so that people have time to prepare.

Even once winds dissipate, the warning can stay in effect until potentially dangerous waters and/or waves have stopped in the area as well. When a warning is issued, those in the area should begin their storm preparations and then evacuate if their local officials direct them to do so.

Hurricane watches are slightly less imminent than warnings. A watch means there are sustained winds of 74 mph or higher possible in the area. These are issued 48 hours in advance.

Hurricane watches and warnings are issued by the National Weather Service and are also broadcast on TV, radio and shared online. Those in an area where a hurricane is expected should pay close attention to messages from local authorities as well.

The difference between a watch and a warning is consistent with all severe weather. A warning always means that the severe weather threat is expected or already happening

A storm surge is also a key term for those in areas where hurricane conditions are possible should know. A storm surge is a type of serious flooding caused during any storm that brings precipitation and causes the sea level to rise above the usual tide level. Storm tide, on the other hand, is the combination of storm surge and that usual tide level. Storm surges can cause the tide to rise upwards of 20 feet in some areas, according to the NHC.

hurricane off the us
A photo of a hurricane formed off the coast of the United States. NOAA