The National Weather Service, the Minnesota Division of Homeland Security and Emergency Management, and other state, county and local agencies have come together to host Severe Weather Awareness Week activities. Thursday, April 16th is the day for tornado drills and working on your safety plans. The schedule for April 16th is as follows:
1:45 PM: 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 but will not activate NOAA Weather Radio.
6:45 PM: Many 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 post on social media but will not activate NOAA Weather Radio.
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 75 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.