TAMPA, Fla. — Since the 1950s, the United States has used a watch and warning alert system for severe weather. Surprisingly, many still don’t know the difference and confuse the two terms. It is unfortunate that they both start with W and sound similar as the meaning and impacts are vastly different.

Watch

This is generally a longer-term FORECAST for severe weather. In other words, WATCH for updates and storms to develop.

Watches are issued for a long period of time (6-12 hours) and for a large geographic area. In this example, a severe thunderstorm watch issued recently for Southern Louisiana. Notice a massive amount of area with the “possibility” of severe storms.

If you were in this area, you should continue to keep up with the weather and watch the situation closely. No need to do anything other than that. 

Warning

A warning, on the other hand, is a quick local bulletin that severe weather has been spotted or detected on radar.

For the past decade, warnings for severe local storms are no longer issued on a county level, but a polygon is issued to show the warning spot. If a tornado or flash flood warning is issued, your cell phone might go off if you are located inside the polygon.

A warning means you should take action because the severe weather (tornado, hail, high winds, flash flooding) is occurring. The warning is usually issued for as short of a time as possible (maybe 15-60 minutes) and for as small of an area as possible.

In our Louisiana example, you can see the warning polygon for a tornado is only in a small portion of the larger watch area issued earlier.

Sometimes you will also see us issue numerous weather alerts during summer thunderstorms. These are for storms that aren’t severe and don’t have an official warning, but you still need to know about them. Think of them as a half-way point between a watch and a warning.

With the summer season almost here, you will see many of our weather alerts for lightning, heavy rain, gusty winds, and street flooding scroll across the bottom of your TV screen in the coming months.