During a tornado warning, you may hear outdoor sirens, NOAA weather radio alerts, Wireless Emergency Alerts on phones, or TV emergency alert tones. Understanding each sound and what it means can save critical seconds during an emergency.
Loud sirens designed to alert outdoor audiences. Usually 3-5 minute constant tone.
Digital alert tone followed by voice warning. Distinct alert tones for different warnings.
Phone alarm plus vibration plus voice/text alert. Distinct WEA tone.
Broadcast emergency alert tones followed by voice warning.
Constant, unwavering high-pitched sound lasting 3-5 minutes. Most common tornado warning siren.
Some jurisdictions use alternating high-low tones. Distinct pattern.
Rising and falling pitch. Less common but used in some areas.
Outdoor sirens are the warning to get inside immediately. They're meant for outdoor audiences, not indoor sheltering decisions. If you're inside, you shouldn't rely on sirens alone.
Most communities test sirens:
If you hear a siren and don't know if it's a test, verify via weather radio, phone alert, or TV before ignoring.
First: Loud digital alarm (attention signal). This is a beeping/tone pattern.
Then: Recorded voice announcing the warning type, location, and details.
Distinct rising-tone pattern. Loud enough to wake you.
Combined with vibration.
Brief text with warning type and area.
iPhone: Settings → Notifications → scroll to Emergency Alerts. Android: Settings → Notifications → Emergency Alerts. Enable all critical categories.
Distinct 3-tone sequence. Emergency Alert System signature sound.
Then: TV station cuts to weather. Radio interrupts programming.
Weather service warning read verbatim.
The specific tone frequency used by NOAA weather radio. Distinct and unmistakable.
Alert outdoor audiences to go inside. Not designed to reach indoor listeners.
Alert those already indoors to take cover. Weather radio, phone, TV alerts are for this purpose.
You need multiple warning sources:
When you hear ANY of these warning sounds:
All-clear is more nuanced:
Rare designation. Confirmed violent tornado approaching populated area. Even more urgent than tornado warning. May trigger additional siren activation.
Additional designation for confirmed strong/violent tornadoes.
Multiple warning sounds serve different purposes. Outdoor sirens are for outdoor audiences. NOAA weather radios, phone WEA alerts, and TV/radio warnings are for indoor sheltering decisions. A layered warning approach maximizes your chances of hearing the alert and responding effectively.
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