This week is Severe Weather Awareness Week in Minnesota with the National Weather Service presenting information daily about various topics on severe weather safety.

Thursday, April 11, the NWS will cover tornadoes with the day featuring tornado drills and educating people on tornado safety.

At approximately 1:45 PM and 6:45 PM on Thursday, most counties in Minnesota will activate outdoor warning siren systems and other notification systems. The choice to activate sirens is a decision made by the counties and cities.

The NWS and others will also post on social media. NOAA Weather Radio will also activate with the Routine Weekly Test code.

Counties and cities own the sirens, and therefore decide how and when to activate them. The National Weather Service does not sound them.

There are many different policies regarding siren activation that are used by the various cities and counties. Some will activate sirens across the entire county for tornado warnings only. Others will activate sirens countywide for tornado warnings and all severe thunderstorm warnings. Some will activate sirens across the entire county for tornado warnings and severe thunderstorms that have winds of at least 70 or 80 mph. Others will activate sirens only for portions of counties. Local officials may also sound the sirens anytime they believe severe weather is a threat, even if there is no warning from the National Weather Service.

Sirens normally sound for about three minutes, and then go silent. It is very rare to keep the sirens sounding for the entire warning, since that would cause the backup battery to run out, which would be critical in the event that power goes out. Furthermore, the siren motor will fail much more quickly if the siren sounds continuously. Some jurisdictions may repeat siren activation every few minutes.

There is no such thing as an “all-clear” for storms.

Please check with your local public safety officials for details on when warning sirens are sounded in your community.

View more Severe Weather Awareness Week topics, HERE.