What do all the tropical alerts really mean?

Hurricane warning flags fly for Hurricane Ian in South Carolina. A Hurricane Warning is just one of many alerts that are issued for tropical storms and hurricanes. (AP Photo/Alex Brandon) (Alex Brandon, Copyright 2022 The Associated Press. All rights reserved.)

JACKSONVILLE, Fla. -- – You’ve gotten the push alerts that Tropical Storm Watches, Storm Surge Warnings and Tropical Storm Warnings are in effect. What do all these alerts mean?

📹 WATCH EXPLAINER: Understanding all the tropical alerts

Watch vs. Warning

The first thing to know is the difference between a watch and a warning.

A watch means conditions are favorable for something to occur. This does not mean it will occur, and sometimes nothing happens.

When a watch is issued, it means to “watch” weather conditions in the future. It is also an opportunity to prepare.

Watch vs. Warning definition

A warning means a weather event is highly likely or is occurring. A warning means preparations should be rushed to completion, as the weather or flooding could deteriorate quickly.

Tropical Storm Watches and Warnings

Tropical Storm alerts are issued when tropical storm conditions are possible or highly likely. Tropical storm force winds are sustained winds at or above 39 mph.

Tropical Storm Watch vs. Warning

A Tropical Storm Watch is issued when 39 mph+ winds are possible in the area. These are issued 48 hours ahead of when the winds may increase.

Again, a watch does not mean it’s imminent, and tropical storm conditions may not occur.

A Tropical Storm Warning is issued when 39 mph+ winds are likely or imminent. These are issued 36 hours ahead of when the winds are expected to increase.

Hurricane Watches and Warnings

Hurricane Watches and Warning follow the same idea as tropical storm alerts, but the threshold is higher.

Hurricane-force winds are sustained at or above 74 mph. These winds are often capable of producing damage to homes and structures.

Hurricane Watch vs. Warning

A Hurricane Watch is issued when 74+ mph winds are possible in the area. These are again issued 48 hours ahead of when the winds may increase.

Hurricane Watches do not mean hurricane conditions are likely. In fact, these are often issued together with Tropical Storm Warnings to signify the possibility of an upgrade to hurricane conditions.

A Hurricane Warning is issued when 74+ mph winds are likely or imminent. These are also issued 36 hours ahead of when the winds are expected to increase.

Storm Surge Watches and Warnings

Storm surge alerts are the newest alerts that are issued. These are issued when storm surge could become or is expected to become an issue.

In this region, storm surge alerts can be issued for the entire coastline, and the St. Johns River basin, as storm surge and elevated tidal levels can be possible on the river and its tributaries.

Storm Surge Watch vs. Warning

A Storm Surge Watch is issued when storm surge that could be life-threatening is possible. This again means a surge event is possible, but not necessarily likely. This watch is issued 48 hours before the first surge event is expected.

A Storm Surge Warning is issued when storm surge is likely or imminent. This is issued 36 hours before the first surge event is expected.

Storm surge is difficult to forecast due to a variety of factors, but a warning does signify some surge is expected.

Knowing what all the tropical alerts mean can help you better understand what specific threats may occur in your area. And remember, no two storms are the same and the impacts will be different every time.


About the Author:

David Heckard is The Weather Authority's Assistant Chief Meteorologist.