Frequently Asked Questions

• The OWSS will be activated upon receipt of a tornado warning issued by the National Weather Service (NWS) in Polk County.
• Severe Thunderstorm Warnings where forecasted or actual wind speeds reach or exceed 70mph (61kts)
• Sirens will sound in a cycle of 3-5 minutes, followed by a 10-15-minute break for the duration of the threat (warning period).

Please note that cities do perform a monthly siren test to ensure all sirens are functioning. The entire system is tested at 1 p.m. on the first Saturday of each month unless severe weather is imminent. 

When the sirens are heard, go inside and tune in to local media to get more information.

Sirens are an outdoor warning system designed only to alert those who are outside that something dangerous is approaching.

People should be indoors and monitoring local media for updates on the storm.

Sirens are typically activated by city or county officials, usually a police or fire department or emergency management personnel.  Check with your city or county officials to learn more.

When thunderstorm winds exceed 70 mph, trees can be uprooted or snapped. Hail that is golf ball sized or larger can break windows. Both of these things pose a direct risk to life if people are caught outdoors.

The safest approach is to be proactive and use all of the information available to protect yourself and your family from threatening weather. Nothing can replace common sense. If a storm is approaching, the lightning alone is a threat. Sirens are only one part of a warning system that includes preparation, emergency and severe weather alerts, NOAA Weather Radio, and local media.

In the event of an emergency or severe weather, it’s important to stay informed. Warren County Emergency Management utilizes “Alert Iowa” – State of Iowa’s official emergency notification system. Alerts can provide valuable seconds for you to seek shelter and can help keep you safe during an emergency.

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The National Weather Service also says every home and business should have a NOAA Weather Radio All-Hazards. NOAA Weather Radio is like a smoke detector for severe weather, and it can wake you up when a warning is issued for your area so you can take appropriate action.

A Tornado WATCH means Be Prepared. A Tornado WARNING means Take Action! weather.gov/safety/tornado-ww

 Don’t underestimate the power of water. It only takes 6 inches of fast-moving water to knock over and carry away an adult, and 12 inches to carry away a small car. Turn Around Don’t Drown!