Tornadoes are powerful and destructive. Recognizing the signs of an approaching tornado is important for personal safety and provides time to seek shelter. Understanding atmospheric cues and official alert systems enhances preparedness when severe weather threatens.
Visual Indicators
Observing the sky provides early signs of a developing tornado. A wall cloud, a lowered, rotating base from a parent thunderstorm, suggests conditions are favorable for tornado formation. Its rotation signals an increased likelihood of a tornado developing.
Funnel clouds are rotating columns of air extending from the cloud base, but are not considered tornadoes until they make ground contact or have a debris cloud beneath them. Even without a fully developed funnel, a swirling cloud of dust and debris near the ground indicates intense winds and a tornado in progress. Rapid, organized rotation within the clouds, particularly at the storm’s base, is another strong visual cue. A dark or greenish sky, often associated with intense thunderstorms and large hail, can precede tornado activity.
Auditory Indicators
While visual signs often precede a tornado, specific sounds indicate one is very close. The most reported auditory cue is a continuous, low-pitched roar, frequently compared to a freight train or jet engine. Unlike the intermittent rumble of thunder, this sound is persistent and grows louder as the tornado approaches.
Other sounds, such as rushing wind, breaking glass, or crashing noises, may be heard if the tornado is very near or impacting structures. Relying solely on auditory cues means the tornado is often upon you, highlighting the importance of earlier visual or official warnings.
Official Warning Systems
Official warning systems provide the most reliable and timely alerts for tornado threats. It is important to distinguish between a tornado watch and a tornado warning. A tornado watch means conditions are favorable for tornadoes to form in a broad area, signaling preparedness. Conversely, a tornado warning indicates a tornado has been sighted or detected by radar, meaning it is imminent or occurring, requiring immediate action.
Multiple channels disseminate these alerts. NOAA Weather Radio is a nationwide network broadcasting continuous weather forecasts, warnings, and hazard information directly from the National Weather Service. These radios can be programmed to alert for specific geographic areas, activating with a tone and broadcasting relevant information. Wireless Emergency Alerts (WEA) deliver emergency messages, including tornado warnings, to mobile devices in affected areas, often with a unique tone and vibration. Local outdoor warning sirens also provide an audible alert for communities, signaling imminent danger and prompting individuals to seek shelter. Having multiple ways to receive alerts ensures critical information is received, even if one system experiences an outage.